Vertiv Liebert STS2 User Manual

Liebert® STS2 /PDU

User Manual—250A-800A, Three-Phase, 60 Hz

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Vertiv™| Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017

TABLE OF CONTENTS

CONTACTING VERTIV™ FOR SUPPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . INSIDE FRONT COVER

IMPORTANT SAFETY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

1.0 UNPACKING AND INSPECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.1 External Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

1.2 Unloading and Handling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

1.2.1 Handling Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2.2 Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.3 Internal Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.0 LOCATION CONSIDERATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.1 Recommended Minimum Service Clearances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

2.2 Heat Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

2.3 Operating Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

2.4 Altitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3.0 LOCATING THE LIEBERT STS2/PDU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.1 Anchoring the Unit to the Floor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

3.2 Positioning the 250A Only Liebert STS2/PDU Without Anchoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

4.0 POWER AND CONTROL WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

4.1 Input and Output Power Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

4.2 System Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.3 Control Wiring Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.4 Remote Source Selection Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.5 Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

5.0 OUTPUT POWER WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

5.1 Customer Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

6.0 OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6.1 Programmable Relay Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

6.2 Input Contact Isolator Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

6.3 Comms Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

6.4 Liebert IntelliSlot™ Web/485 Card With Adapter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

6.5 Remote Source Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

6.6 Key Lockout Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

6.7 Static Switch Redundant Output Breaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

6.8 Inline Panelboards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

6.9 I-Line Panelboards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

6.10 Subfeed Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

6.11 K-Factor Transformers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

6.12 Surge Suppression System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

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7.0 INSTALLATION DRAWINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

8.0 INTRODUCTION TO LIEBERT STS2/PDU OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 68

8.1 System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

8.1.1 Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

8.1.2 Reliability and Agency Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

8.1.3 Factory Backup and Service Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

8.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

8.2.1 Normal (Preferred Source) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

8.2.2 Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

8.2.3 Transfer Inhibit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

8.2.4 Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

8.3 Operator Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

9.0 THEORY OF OPERATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

9.1 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

9.1.1 Liebert Static Transfer Switch 2/Power Distribution Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

9.1.2 Source Transfer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

9.1.3 Automatic Transfer/Retransfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

9.1.4 Emergency Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

9.1.5 Load Current Transfer Inhibit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

9.1.6 SCR Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

9.1.7 On/Off Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

9.2 Detailed Component Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

9.2.1 Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

9.2.2 Circuit Breakers and Non-Automatic Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

9.2.3 SCRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

9.2.4 Logic Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

9.2.5 Audible Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

9.2.6 RS-232 Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

10.0 OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

10.1 Normal System Turn-On. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

10.2 Manual Transfer / Preferred Source Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

10.3 Enabling Remote Source Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

10.4 Maintenance Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

10.4.1 Bypass Procedures for Source 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

10.4.2 Bypass Procedures for Source 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

10.5 Normal System Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81

10.5.1 Shutdown in Static Transfer Switch Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81

10.5.2 Shutdown in Maintenance Bypass Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81

11.0 ALARMS AND FAULTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

11.1 Event Mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

11.2 Event and History Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

11.2.1 Event Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

11.2.2 History Log. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

11.3 Alarm Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

11.4 List of Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

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12.0 COMMUNICATION INTERFACES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

12.1 Using the RS-232 Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

12.1.1 Connecting and Using a Terminal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

12.1.2 Configuring the Liebert STS2/PDU via the Terminal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

12.1.3 Setting Bitpacked Options With the Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

12.1.4 Setting Event Masks with the Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

13.0 TOUCHSCREEN DISPLAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

13.1 Display Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

13.2 Menu Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

13.2.1 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

13.3 Mimic Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

13.4 Event Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

13.5 Event Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

13.6 Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

13.7 Configuration Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

13.7.1 Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

13.7.2 Source Transfers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

13.7.3 Startup Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

13.7.4 Bypass Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

13.7.5 Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114

13.7.6 Logo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114

13.8 Cleaning the LCD Touchscreen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

14.0 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115

14.1 System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

14.1.1 Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

14.1.2 Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115

14.1.3 Output Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

14.1.4 System Current Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

14.1.5 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116

14.1.6 Electrical Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116

14.1.7 Surge Suppression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

14.1.8 Response Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116

14.1.9 Environmental Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

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14.2 System Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

14.2.1 Frame and Enclosure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

14.2.2 Casters - 250A only. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

14.2.3 Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

14.2.4 Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118

14.2.5 Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

14.2.6 Cable Entrance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118

14.2.7 Doors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

14.2.8 Color Graphical Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

14.2.9 RS-232 Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119

14.2.10 Terminal Port Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

14.2.11 RS-232 Interface Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

14.2.12 Maintenance Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

14.2.13 Fuseless Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

14.2.14 Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

15.0 EVENT MESSAGE HELP TEXT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

16.0 MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

16.1 Proper Tightening of Nuts and Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

16.2 Testing the Liebert STS2/PDU. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

16.3 Changing the Air Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

17.0 CUSTOMER SETTINGS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

17.1 Programmable Relay Board Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

17.2 Input Contact Isolator Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

FIGURES

Figure 1 Recommended derating for high altitude operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 2 Maximum ambient temperature for full load operation at higher altitudes . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3 Typical Liebert STS2/PDU, one-line diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 4 Typical Liebert STS2/PDU, one-line diagram, with dual static switch output circuit breakers

(not available on 250A units) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 5 Typical Liebert STS2/PDU, one-line diagram, with inline distribution, dual static switch output

circuit breakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Figure 6 Typical Liebert STS2/PDU, one-line diagram, with I-Line distribution, dual static switch output

circuit breakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Figure 7 Outline drawing, 250A Liebert STS2/PDU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Figure 8 Outline drawing, 250A Liebert STS2/PDU with right side I-Line distribution . . . . . . . . . . . . . . . . . . . .18

Figure 9 Outline drawing, 250A Liebert STS2/PDU with right side inline distribution. . . . . . . . . . . . . . . . . . . . .19

Figure 10 Outline drawing, 250A Liebert STS2/PDU with left side I-Line distribution. . . . . . . . . . . . . . . . . . . . . 20

Figure 11 Outline drawing, 250A Liebert STS2/PDU with left side Inline distribution . . . . . . . . . . . . . . . . . . . . . .21

Figure 12 Outline drawing,400-600A Liebert STS2/PDU with right side inline distribution . . . . . . . . . . . . . . . 22

Figure 13 Outline drawing, 400-600A Liebert STS2/PDU with right side output breaker or I-Line

distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 14 Outline drawing, 400-600A Liebert STS2/PDU with left side inline distribution . . . . . . . . . . . . . . . . 24

Figure 15 Outline drawing, 400-600A Liebert STS2/PDU with left side output breaker or I-Line

distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

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Figure 16 Outline drawing, 800A Liebert STS2/PDU with right side output breaker or I-Line

distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 17 Outline drawing, 800A Liebert STS2/PDU with right side inline distribution . . . . . . . . . . . . . . . . . . . 27

Figure 18 Outline drawing, 800A Liebert STS2/PDU with left side output breaker or I-Line

distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 19 Outline drawing, 800A Liebert STS2/PDU with left side inline distribution. . . . . . . . . . . . . . . . . . . . . 29

Figure 20 Outline drawing, 250A Liebert STS2/PDU with key lockout switch option. . . . . . . . . . . . . . . . . . . . . . 30

Figure 21 Outline drawing, 400-600A Liebert STS2/PDU, inline distribution, right side with key

lockout switch option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Figure 22 Outline drawing, 800A Liebert STS2/PDU, inline distribution, right side with key lockout

switch option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 23 Electrical field connections, 250A Liebert STS2/PDU input/output with CB8. . . . . . . . . . . . . . . . . . . 33

Figure 24 Electrical field connections, 250A Liebert STS2/PDU input with CB3 . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 25 Electrical field connections, 250A Liebert STS2/PDU input with CB3 & CB3A . . . . . . . . . . . . . . . . . 35

Figure 26 Electrical field connections, 400-600A Liebert STS2/PDU input with CB3. . . . . . . . . . . . . . . . . . . . . 36

Figure 27 Electrical field connections, 400-600A Liebert STS2/PDU input with CB3 and CB3A . . . . . . . . . . 37

Figure 28 Electrical field connections, 800A Liebert STS2/PDU input with CB3. . . . . . . . . . . . . . . . . . . . . . . . . . 38

Figure 29 Electrical field connections, 800A Liebert STS2/PDU input with CB3 and CB3A . . . . . . . . . . . . . . . 39

Figure 30 Electrical field connections, 250A Liebert STS2/PDU output with inline panelboards. . . . . . . . . . . 40

Figure 31 Electrical field connections, 400-800A Liebert STS2/PDU output with inline panelboards . . . . . .41

Figure 32 Electrical field connections, Liebert STS2/PDU output with I-Line panelboard . . . . . . . . . . . . . . . . . 42

Figure 33 Electrical field connections, 400-600A Liebert STS2/PDU with right side output breaker . . . . . . 43

Figure 34 Electrical field connections, 400-600A Liebert STS2/PDU with left side output breaker . . . . . . . 44

Figure 35 Electrical field connections, 800A Liebert STS2/PDU with right side output breaker . . . . . . . . . . . 45

Figure 36 Electrical field connections, 8600A Liebert STS2/PDU with left side output breaker . . . . . . . . . . . 46

Figure 37 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring . . . . . . . . . . . . . . . . . . . . . 47

Figure 38 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, breaker section . . . . . 48

Figure 39 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, STS section . . . . . . . . 49

Figure 40 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, left side

distribution cabinet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Figure 41 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, left side one-line . . . . . 51

Figure 42 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, left side one-line

with CB3A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Figure 43 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, right side

one-line. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Figure 44 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, right side

one-line with CB3A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Figure 45 Control wiring, 800A Liebert STS2/PDU, left side distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Figure 46 Control wiring, 800A Liebert STS2/PDU, right side distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Figure 47 Control connection location, 250A Liebert STS2/PDU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Figure 48 Control connection location, 400-800A Liebert STS2/PDU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Figure 49 Control location drawing conduit box, top entry, 400-600A Liebert STS2/PDU . . . . . . . . . . . . . . . . 59

Figure 50 Control wiring for the programmable relay board option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Figure 51 Control wiring for the input contact isolator board option. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

Figure 52 Control wiring for Comms board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Figure 53 Control wiring for the Liebert IntelliSlot™ Web/485 Card With Adapter option. . . . . . . . . . . . . . . . . . 63

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Figure 54 Control wiring for the RS-232 Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Figure 55 Control wiring for remote source selection option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Figure 56 Color LCD touchscreen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Figure 57 Liebert STS2/PDU touchscreen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Figure 58 Liebert STS2/PDU touchscreen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Figure 59 Source Transfer screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Figure 60 Gate board viewing slot locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Figure 61 Liebert STS2/PDU touchscreen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

Figure 62 Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Figure 63 Keyboard and keypad displays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Figure 64 Key lockout switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

Figure 65 Event Mask dialog box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Figure 66 User settings dialog box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101

Figure 67 Source setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Figure 68 PDU setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Figure 69 Comm options dialog box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Figure 70 Modem dialog box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Figure 71 Input Contact Isolator dialog box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

Figure 72 Programmable relay board dialog box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Figure 73 System options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Figure 74 PDU options button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Figure 75 Event log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Figure 76 History log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Vertiv | Liebert STS2/PDU User Manual | Rev. 6 | 10/17 vi

TABLES

Table 1 Shipping weights (typical) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Table 2 Heat output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Table 3 Input/output conduit plate specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 4 Remote source selection terminal block. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Table 5 Terminal block 1 and terminal block 2 wire connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 6 Distribution configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Table 7 Programmable relay board pinout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Table 8 Interconnection wiring, from STS section to breaker section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Table 9 Interconnection wiring from Breaker Section to Distribution Section . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Table 10 Input circuit breaker schedule, 250-800A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Table 11 Output circuit breaker schedule, 250-800A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Table 12 Non-automatic breaker schedule, 250-800A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Table 13 Event messages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Table 14 Terminal commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Table 15 Value types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Table 16 Group settings and values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Table 17 Binary-hexadecimal conversions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Table 18 Setpoint parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Table 19 PDU setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Table 20 Standard settings for programmable relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

Table 21 Input voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Table 22 Output voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Table 23 System current ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Table 24 Electrical requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Table 25 Unit short circuit withstand capability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Table 26 Frame sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Table 27 MTA plug pin-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Table 28 DB9 pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Table 29 RS-232 settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Table 30 Torque tightening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Table 31 Branch circuit breakers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Table 32 Programmable relay board settings record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Table 33 Input contact isolator settings record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

Vertiv | Liebert STS2/PDU User Manual | Rev. 6 | 10/17 vii

Vertiv | Liebert STS2/PDU User Manual | Rev. 6 | 10/17 viii

IMPORTANT SAFETY INSTRUCTIONS

SAVE THESE INSTRUCTIONS

This manual contains important instructions that should be followed during the installation and maintenance of
the Liebert Static Transfer Switch 2/Power Distribution Unit (Liebert STS2/PDU).

Read this manual thoroughly, paying special attention to the sections that apply to your installation, before
working with the Liebert STS2/PDU. Retain this manual for use by installing personnel.

Refer to 1.2.1 - Handling Considerations before attempting to move the unit.

WARNING

Risk of electric shock. Can cause injury or death.

Before proceeding with installation, read all instructions, verify that all the parts are included and check
the nameplate to be sure the voltage matches available utility power.

This unit is supplied by more than one power source. The unit contains hazardous voltages if any of the
input sources are on, even when the unit is in bypass. To isolate the unit, turn off and lock out all input
power sources.

Verify that all input power sources are de-energized and locked out before making connections inside
unit.

Lethal voltages exist inside the unit during normal operation. Only qualified service personnel should
perform maintenance on the Liebert STS2/PDU.
Installation and operation must comply with all national and local laws and regulations.

WARNING

Risk of electric shock. Can cause injury or death.
Under typical operation and with all Liebert STS2/PDU doors closed, only normal safety precautions are

necessary. The area around the Liebert STS2/PDU should be kept free of puddles of water, excessive
moisture, flammable liquids, gases, corrosive substances and debris.

Only properly trained personnel wearing appropriate safety headgear, gloves, shoes and glasses should
perform maintenance on the Liebert STS2/PDU. When performing maintenance on any part of the
equipment under power, service personnel and test equipment should be located on rubber mats. Service
personnel should wear insulating shoes for isolation from direct contact with the floor.
One person should never work alone, even if all power is disconnected from the equipment. A second
person should be standing by to assist and summon help in case of an accident.

NOTICE

Risk of damage from improper installation.
The input sources to the Liebert STS2/PDU must be grounded-wye sources. Input sources other than solidly grounded-

wye sources may cause damage to the switch.

Liebert neither recommends nor knowingly sells this product for use with life support or other FDA-designated
“critical” devices.

The Liebert STS2/PDU is suitable for indoor use only.

The unit is designed to operate from solidly grounded AC power sources only. Provide input over-current
protection in accordance with the unit ratings. Wire and ground the unit according to national and local electrical
safety codes. All wiring should be installed by a properly trained and qualified electrician.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 1

A thorough equipment inspection and supervised startup by qualified service personnel are strongly
recommended at these times:

1. Before unit is placed into service for the first time

2. After equipment relocation, and

3. After the unit has been de-energized for an extended period.

WARNING

Risk of heavy unit falling over. Can cause equipment damage, injury or death.
Locate the center of gravity symbols and determine the unit’s weight

before handling the cabinet.
Read all instructions before attempting to move the unit, lift it, remove packaging or prepare

the unit for installation.

NOTICE

This unit complies with the limits for a Class A digital device, pursuant to Part 15 Subpart J of the FCC rules and
EN550022. These limits provide reasonable protection against harmful interference in a commercial environment. This
unit generates, uses and radiates radio frequency energy and, if not installed and used in accordance with this instruction
manual, may cause harmful interference to radio communications. Operating this unit in a residential area may cause
harmful interference that the user must correct at his own expense.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 2

1.0 UNPACKING AND INSPECTIONS

NOTE

Read the entire manual before beginning to install the Liebert STS2/PDU. Upon delivery of the Liebert
STS2/PDU, the installer should perform the following steps to ensure a high-quality installation.

A high-quality installation begins on the receiving dock. The Liebert STS2/PDU and its packaging should be
inspected when the unit is delivered. If the packaging is not damaged, unpack the unit and conduct an internal
inspection before beginning installation. This section discusses inspecting and unpacking the Liebert
STS2/PDU.

1.1 External Inspections

1. While the Liebert STS2/PDU is still on the truck, inspect the equipment and shipping container(s) for any signs of damage
or mishandling. Do not attempt to install the system if damage is apparent.

2. Upon receipt and before unpacking, inspect the shipping crate for damage or mishandling.
Check the Shock-Watch

• If the indicator is red, note the condition on shipper’s receipt and check for concealed damage.

• If any shipping damage is observed, file a damage claim with the shipper within 24 hours and contact your local Liebert

representative or Vertiv Services at 1-800-543-2378 to inform them of the damage claim and the condition of the
equipment.

3. Locate the bag containing the keys for the front access door. The bag is attached to the cabinet.

4. Compare the contents of the shipment with the bill of lading. Report any missing items to the carrier and to Vertiv Services
immediately.

5. Check the nameplate on the cabinets to verify that the model numbers correspond with the one specified. Record the
model numbers and serial numbers in the front of this installation manual. A record of this information is necessary should
servicing be required.

6. If unit is to be stored before installation, it is recommended to store the unit in a dry environment with temperatures in the
range of -40 to 176°F (-40 to 80°C). Use original packing materials or other suitable means to keep the unit clean. When
opening the shipping crate, use care not to puncture the container with sharp objects.

™

indicator.

1.2 Unloading and Handling

WARNING

Risk of heavy unit falling over. Can cause equipment damage, injury or death.

Locate the center of gravity symbols and determine the unit’s weight
before handling the cabinet.

Do not exceed a 15-degree tilt with the forklift. Read all instructions before attempting to
move the unit, lift it, remove packaging or prepare the unit for installation.

NOTICE

When moving the unit by forklift, lift the unit from the rear so as to protect the front panel.
Also, if moving the unit by forklift or pallet jack after it has been removed from the pallet, be aware of the location of the
casters and stabilizing feet (if the unit is so equipped) so as not to damage them.

Most Liebert STS2/PDU models are contained in one cabinet. The 800 amp units are contained in two cabinets,
shipped on two pallets and connected together in the field.

The unit can be moved by forklift or pallet jack. However, because the weight distribution in the cabinet is
uneven, use extreme care during handling and transporting.

See 1.2.2 - Unit Preparation for instructions on removing the Liebert STS2/PDU from the pallet.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 3

1.2.1 Handling Considerations

The Liebert STS2/PDU is bolted to a wood shipping pallet to allow handling by forklift or a pallet jack.

WARNING

Risk of heavy unit falling over. Can cause equipment damage, injury or death.
Exercise extreme care when handling Liebert STS2/PDU cabinets to avoid equipment damage or injury to

personnel.

The cabinet can be safely tilted 15 degrees in any direction by forklift. If moving the unit up a ramp on its
casters (if the unit is so equipped) or a pallet jack, ensure that the incline does not exceed 15 degrees.

Locate the center of gravity symbols and determine the unit’s weight before handling the cabinet.

Check the unit size and weight. Refer to the cabinet drawings furnished with the unit for size and weight. Typical
cabinet dimensions are shown in Figures 7 through 22. Typical unit crated weights are:

Table 1 Shipping weights (typical)

Model Weight, lb. (kg)

250A 3813 (1733)

400A 4808 (2185)

600A 5892 (2678)

800A Module A* 4180 (1900)

800A Module B* 4723 (2147)

*800A ships on two separate pallets

Plan the route. Review the route over which the unit will be transported to its installation location to ensure that
all passages are large enough to accommodate the unit and support the weight.

Check for any non-negotiable corners or offsets in hallways. Before moving the unit to the intended location,
review 2.0 - Location Considerations.

1.2.2 Unit Preparation

The unit can be removed from the pallet before it is moved to its location.

Complete the following steps to properly remove the Liebert STS2/PDU from the shipping pallet:

1. Set the pallet in a level area with enough room to maneuver and remove the unit.

2. Remove the bolts holding the unit to the shipping pallet (located in the base of the unit).

3. Remove the shipping blocks from under the frame of the unit.

4. Use a forklift to raise the unit off the pallet and onto the floor. On the 250A unit ensure that the forklift is clear of the unit's
casters and stabilizing feet. Lift the unit from the rear.

5. Conduct an internal inspection of the unit. See the list in 1.3 - Internal Inspection.

1.3 Internal Inspection

After the Liebert STS2/PDU has been unpacked, conduct an internal inspection:

1. Verify that all items have been received.

2. If spare parts were ordered, verify their arrival.

3. After the Liebert STS2/PDU has been removed from the pallet, open the door and remove cabinet panels to check for
shipping damage to internal components.

4. Check for loose connections or unsecured components in the cabinet(s).

5. Check for any unsafe condition that may be a potential safety hazard.

After the Liebert STS2/PDU has been inspected and no problems are found, the unit can be moved to its
installation location. If using a forklift, remember to lift the unit from the rear.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 4

2.0 LOCATION CONSIDERATIONS

The Liebert STS2/PDU should be placed in a clean, cool and dry location. The 250A unit without an output
cabinet requires only front access for installation and maintenance. Both front and side access are required for
installation and maintenance of 400-800A units and 250A units with output cabinet. The output cabinet comes
factory-installed or either the right or left side, depending on how it was ordered. It cannot be moved from one
side to the other in the field.

Adequate space is required above the unit for conduit (if configured as such) and cooling air flow. This section
provides specific information for these considerations.

The unit is designed with top and bottom cable terminations to allow maximum flexibility in its installation. Units
with output inline panelboards are bottom exit only. If bottom cable entry and exit is used, sufficient cable
bending space must be provided by a raised floor or a floor stand.

For dimensions of each unit, see Figures 7 through 22. If your unit is equipped with an optional key lockout
switch, see Figures 13 through 21 for the location of that switch.

2.1 Recommended Minimum Service Clearances

The recommended service clearances are at the front and side, if equipped with output cabinet. The minimum
service clearance required by the National Electrical Code (NEC) Article 110-26 is 36 in. (91cm) for units with
voltages up to 150V to ground and 42 in. (107cm) for units with voltages over 150V to ground. Clearance of at
least 18 in. (46cm) is required above the unit for cooling air flow.

2.2 Heat Output

The unit produces minimal heat during normal operation.

Table 2 Heat output

Switch Size

250A 11,737 (3.44)

400A 19,295 (5.66)

600A 29,238 (8.57)

800A 39,238 (11.50)

Heat Output

BTU/Hr (kW)

2.3 Operating Environment

The unit is designed to be installed indoors where the ambient air temperature is in the range of 32° to 104°F
(0°C - 40°C) with a relative humidity of 0% to 95% non-condensing, up to an altitude of 4000 feet (1200 meters).

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 5

2.4 Altitude

0

10,000

(3048)

9500

(2896)

9000

(2743)

8500

(2591)

8000

(2438)

7500

(2286)

6000

(1829)

5500

(1676)

7000

(2134)

6500

(1981)

5000

(1524)

4500

(1372)

4000

(1200)

100

86

88

90

92

94

96

98

Rating (%)

Altitude, Feet (M) Above Sea Level

0

10,000

(3048)

9500

(2896)

9000

(2743)

8500

(2591)

8000

(2438)

7500

(2286)

6000

(1829)

5500

(1676)

7000

(2134)

6500

(1981)

5000

(1524)

4500

(1372)

4000

(1200)

104.0 (40)

86.0 (30)

87.8 (31)

94.1 (33)

93.2 (34)

95.0 (35)

96.8 (36)

98.6 (37)

Maximum Ambient

Temperature, °F (°C)

Altitude, Feet (M) Above Sea Level

102.2 (39)

100.4 (38)

89.6 (32)

The standard units are designed for full load operation up to 4000 feet (1200m) above sea level. See Figure 1 for
recommended deratings for altitudes greater than 4000 feet (1200m).

Figure 1 Recommended derating for high altitude operation

Operation at full load at a higher altitude can be accommodated in ambient temperatures less than 104°F (40°C)
ambient. Figure 2 shows the maximum allowable ambient temperature for full load operation at altitudes above
4000 feet (1200m).

Figure 2 Maximum ambient temperature for full load operation at higher altitudes

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 6

3.0 LOCATING THE LIEBERT STS2/PDU

This section provides instructions for leveling the Liebert STS2/PDU and anchoring the unit to the floor, should
that be required.

3.1 Anchoring the Unit to the Floor

The Liebert STS2/PDU can be anchored to the concrete floor to ensure stability for the unit in the event of
seismic activity.

3.2 Positioning the 250A Only Liebert STS2/PDU Without Anchoring

The 250A Liebert STS2/PDU is furnished with casters and stabilizing feet. After final positioning of the unit,
adjust the stabilizing feet located in each corner of the frame base to stabilize the unit.

For stabilizing feet details, see Figures 7 through 11.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 7

4.0 POWER AND CONTROL WIRING

WARNING

Risk of electric shock. Can cause injury or death.

This unit is supplied by more than one power source. The unit contains hazardous voltages if any of the
input sources are on, even when the unit is in bypass. To isolate the unit, turn off and lock out all input
power sources.

Verify that all input power sources are de-energized and locked out before making connections inside
unit.
Lethal voltages exist inside the unit during normal operation. Only qualified service personnel should
perform maintenance on the Liebert STS2/PDU.

All power and control wiring must be installed by a licensed, properly trained and qualified electrician. All
power and control wiring must comply with the National Electrical Code and all applicable local codes.

The input power busbars are accessible through the front of the unit. Liebert’s 250A units have PEM nut inserts
designed to allow one-handed tightening. Busbars in the 400-800A units are supplied with holes to
accommodate two-hole lugs.

Cables can be installed through the top or bottom of the unit through removable conduits plates. Units with
output inline panelboards are bottom exit only for output cables.

Unless otherwise labeled, use the recommended tightening torque shown in Tab le 30.

See Figures 12 through 21 for wiring entrance locations.

4.1 Input and Output Power Connections

The input power connections are made to the busbars provided inside the unit (see Figures 26 through 31).
These busbars are accessible through the front of the unit.

Output power connections are handled two different ways, depending on the type of distribution used. Power
connections on standard units with an output breaker are made to the busbars inside the unit. These busbars
are accessible through the front on 250A units and on the side on 400-800A units. See Figures 26 through 31
for details on the busbars. Power connections on units with panelboard distribution are made directly to the
panelboard breakers. Busbars are provided in the output cabinet for ground and neutral connections.

WARNING

Risk of electric shock. Can cause injury or death.

Verify that all input power and control circuits are de-energized and locked out before making
connections inside unit.

The two input power feeds (sources) to the Liebert STS2/PDU should be from two independent sources to avoid
a common source failure.

To ensure proper operation of the Liebert STS2/PDU, the two input sources must be the same nominal voltage
level and phase rotation.

For uninterrupted automatic transfer, the two input sources should be synchronized within 15 degrees.

NOTICE

The input sources to the Liebert STS2/PDU must be grounded-wye sources. Input sources other than solidly grounded­wye sources may cause damage to the switch.

The Liebert STS2/PDU is designed for operation with three-wire, solidly grounded sources only.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 8

See Figures 3 through 6 for typical one-line diagrams. Refer to Figures 26 through 31 for electrical field
connections on all units.

Figure 3 Typical Liebert STS2/PDU, one-line diagram

Source 1

Source 2

CB6

Surge

Suppression

Optional

CB7

Surge

Suppression

Optional

Transformer 1

Neutral

Ground

Transformer 2

CB4

CB1

CB2

CB5

SS1

CB3

SS2

Field-Supplied Wiring

PSP12006
Rev. 1

Figure 4 Typical Liebert STS2/PDU, one-line diagram, with dual static switch output circuit breakers

(not available on 250A units)

Source 1

CB6

Surge

Suppression

Optional

Transformer 1

Neutral

Ground

CB4

CB1

CB2

SS1

SS2

CB3

CB3A

Breaker

Output

Breaker

CB8

Output

CB8

Source 2

CB7

Surge

Suppression

Optional

Transformer 2

CB5

Field-Supplied Wiring

PSP12007
Rev. 1

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 9

Figure 5 Typical Liebert STS2/PDU, one-line diagram, with inline distribution, dual static switch output circuit breakers

Source 1

Source 2

CB6

Surge

Suppression

Optional

CB7

Surge

Suppression

Optional

Transformer 1

Neutral

Ground

Transformer 2

CB4

CB1

CB2

CB5

SS1

SS2

Field-Supplied Wiring

PSP12003
Rev. 3

CB3

CB3A

Subfeed 1

Optional

CB12

CB8 CB9 CB10 CB11

42-Pole Distribution
Panelboard, Typical

Subfeed 2

Optional

CB13

Figure 6 Typical Liebert STS2/PDU, one-line diagram, with I-Line distribution, dual static switch output circuit breakers

Source 1

CB6

Surge

Suppression

Optional

Transformer 1

Neutral

CB4

CB1

SS1

Output
Breaker(s)

CB3

CB3A

I-Line Panelboard

CB7

Ground

CB2

CB5

SS2

Source 2

Surge

Suppression

Optional

Transformer 2

Field-Supplied Wiring

PSP12001
Rev. 2

The input and output power wire size should be based on the overcurrent protection device, observing the NEC
and local codes.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 10

The Liebert STS2/PDU output power, ground and neutral busbars accommodate a wide range of wire sizes. The
Liebert STS2/PDU busbars accommodate standard two-hole lugs.

Table 3 Input/output conduit plate specifications

Rating

250A

400-600A

800A

Maximum Number

of Conduits Size, in.

12 2"

82-1/2"

63" or 3-1/2"

6 2"

4 2-1/2" or 3"

62-1/2"

53" or 3-1/2"

4.2 System Grounding

Equipment grounding—Grounding is primarily for equipment and personnel safety, although proper grounding
also enhances equipment performance.

All input and output power feeds must include an equipment grounding means as required by the NEC and local
codes.

An insulated equipment ground conductor is recommended to run with each input and output power feed. The
equipment ground conductors should be at least the minimum size conductor per the NEC based on the
upstream overcurrent protection device.

WARNING

Risk of electric shock. Can cause injury or death.

If conduit is used as a grounding means, adequate electrical continuity must be maintained at all conduit
connections. Using isolating bushings with a metal conduit can be a safety hazard.

4.3 Control Wiring Connections

No control wiring is needed on the standard Liebert STS2/PDU. Certain options and remote monitoring
configurations require external control wiring. See 6.0 - Options for details.

The customer must supply control wiring to the Liebert STS2/PDU for connection to any monitoring or
communication options. Top and bottom removable conduit plates are provided for control wiring conduit.

Control cables can be installed through the top or bottom of the unit through removable control conduit plates.
A top hat is provided on the 400-600A units for connecting the top entry control wiring conduits (see
Figures 13 through 21). The top hat is turned upside down and ships inside the unit. It must be removed from the
unit and flipped 180 degrees before being reinstalled (see Figure 49). The control wiring top hat does NOT
contain any knockouts for conduit. The installer must drill the appropriate-sized holes for the conduit before
attaching to the top of the Liebert STS2/PDU.

See Figures 47 and 48 for arrangement of optional cards.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 11

4.4 Remote Source Selection Wiring

An optional Remote Source Selection board may be installed in your Liebert STS2/PDU. This board is installed in the
same bay as the communications options. See Figures 47 and 48 for the location of these options. See Figure 55 for
information on the control wiring for the Remote Source Selection option.

The Remote Source Selection allows you choose the preferred input source from a remote location.

Terminal connections allow the customer to remotely select a source to be the preferred source in the same
process as the local source transfer selection.

If both the input contacts are closed, the current selected preferred source shall be retained. If the unit’s
preferred source selection and Remote Source Selection are active at the same time,
the Liebert STS2/PDU follows the last request for a preferred source change, regardless of whether it was from
the local or Remote Source Selection controls.

A six pin terminal block provides the Remote Source Selection connections. Two pairs of wires are used from the
switch to trigger the source selection. You can select the type of switch used for this remote control.
Connections are made to four of the connections, using Form A dry contacts. The contacts are numbered left to
right:

Table 4 Remote source selection terminal block

Contact

1Source 1

2 Isolated ground

3Source 2

4Isolated Ground

5 DO NOT USE

6 DO NOT USE

Connection

See 10.3 - Enabling Remote Source Selection for instructions on enabling the Remote Source Selection option.

4.5 Power Supply

The Liebert STS2/PDU is supplied with redundant power supplies that are designed to operate from a voltage
range of 200V to 600V. The unit is set at the factory to match the nameplate voltage. Field adjustments are not
necessary. If the unit needs to operate at a voltage other than what is listed on the nameplate, contact Vertiv
Services or your local Vertiv representative. Tab le 5 provides transformer tap information.

Table 5 Terminal block 1 and terminal block 2 wire connections

Connect Connect

Vol tag e

200 1 9 1 9 1-7

220 2 12 2 12 6-8

380 1 8 1 8 2-7

415 1 10 1 10 4-7

600 1 12 1 12 6-7

208 1 10 1 10 1-7

240111111 1-7

400 1 9 1 9 3-7

480 1 11 1 11 5-7

Jumper BetweenF1 TB1-XX F2 TB1-YY F3 TB2-XX F4 TB2-YY

NOTICE

Using Tab le 5 , ensure that the wiring for the control transformers matches the input voltage for the unit.
Improper wiring could result in blown fuses.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 12

5.0 OUTPUT POWER WIRING

The Liebert STS2/PDU standard model is provided with a circuit breaker for connecting to the load or a remote
distribution cabinet. Other distribution configurations are available.

The three main types of distributions available for the Liebert STS2/PDU are:

•Output Breaker

• Inline Panelboards—two panelboards (84 poles) on 250A units and four panelboards (168 poles) on 400-800A units.
Square D

•SquareD I-Line
to 400A breakers are available on 800A units.

For other optional distribution methods, contact your local Liebert representative or call 1-800-LIEBERT.

The Liebert STS2/PDU distribution may be mounted on either the right or left side at the customer’s option.
Location of output conduit connections is affected by the location of the output cabinet. See
Figures 8, 9, 12, 13, 16 and 17 for wiring a right-side distribution configuration and Figures 10, 11, 14, 15, 18 and 19
for wiring a left-side distribution configuration. See Figures 23 through 44 for wiring.

See Table 6 for wiring the various output options.

5.1 Customer Connections

The customer is responsible for connections from the Liebert STS2/PDU distribution to the connected load,
either directly or through remote distribution cabinets.

Table 6 Distribution configurations

Distribution Type

Output Breaker

Inline Panelboards

I-Line (Square D) Figure 32

®

and General Electric panelboards are available to accommodate bolt-in or plug-in breakers.

®

Panelboard—designed to accommodate up to 10 plug-in breakers from 100A to 250A. Additionally, 300A

For Details See

Electrical Output

Field Connections

250A Figure 23

400-600A Figure 33

800A Figure 35

250A Figure 30

400-800A Figure 31

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 13

6.0 OPTIONS

This section discusses the options available for the Liebert STS2/PDU. The communications options are also
discussed in 12.0 - Communication Interfaces.

WARNING

Risk of electric shock. Can cause injury or death.

All options must be installed by Vertiv Services or Vertiv factory-authorized service provided by a Vertiv
distributor. The option area and customer control cable area contain hazardous voltages if any of the
input sources are on, even when the unit is in bypass. Turn Off all power sources before installing
customer control cables to any option.

6.1 Programmable Relay Board

The programmable relay board (PRB) provides a means to trigger an external device when an event occurs in
the Liebert STS2/PDU. Each PRB has 8 channels. Each channel has two sets of Form-C dry contacts, rated 1A @
30VDC or 250mA @ 125VAC.

Any alarm or event may be programmed to any channel or channels. Up to ten (10) events may be programmed
to a relay. If multiple events are grouped to one relay, group the events logically to simplify troubleshooting when
an event is triggered. The same alarm or event may be programmed to more than one channel. Up to two
programmable relay boards can be installed in the Liebert STS2/PDU for a total of 16 channels. Programming is
performed through the touchscreen.

See Configuring the Programmable Relay Board Settings on page 109 for default settings and instructions
for reconfiguring the relays. See Figures 47 and 48 for the location of the PRB. See Figure 50 for wiring details.

Table 7 provides the PRB pin-out.

Table 7 Programmable relay board pinout

Channel Pin No. C N.C. N.O.

CH1

TB1

TB2

TB3

TB4

Key: N.O. = Normally Open; N/C. = Normally Closed; C = Common
Note: Pin 16 not used on TB1, TB2 and TB3.

CH2

CH3

CH4

CH5

CH6

CH7

CH8

A1-3 12 3

B4-6 45 6

A7-9 78 9

B 10-12 10 11 12

A 13-15 13 14 15

B1-3 12 3

A4-6 45 6

B7-9 78 9

A 10-12 10 11 12

B 13-15 13 14 15

A1-3 12 3

B4-6 45 6

A7-9 78 9

B 10-12 10 11 12

A 13-15 13 14 15

B1-3 12 3

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 14

6.2 Input Contact Isolator Board

The Input Contact Isolator Board (ICI) provides a Liebert STS2/PDU module interface for up to eight external
user alarm or message inputs to be routed through the Liebert STS2/PDU’s alarm network. The eight contacts
are normally open dry contacts. When a contact closes, an event is triggered.

The Input Contact Isolator options are configured through the Input Contact Isolator dialog box, which is
accessed from the Comm Option dialog box on the touchscreen. You also can program the alarm messages
through this dialog box. See Configuring the Input Contact Isolator Settings on page 107 for instructions on
configuring the connections.

See Figures 47 and 48 for the location of the ICI. See Figure 51 for wiring details.

6.3 Comms Board

The Comms Board provides a communication interface to Liebert SiteScan®, site monitoring product and/or an
external modem. Liebert SiteLink®-12 or Liebert SiteLink®-4 is required for Liebert SiteScan to communicate with
the Liebert STS2/PDU.

The Comms Board is equipped with an RS-422 communication port for communication to a Liebert SiteScan
monitoring system using a 2-wire twisted pair for reliable communication up to 1000 meters (3281 feet).
Information available from the RS-422 port includes the present switch status information, all monitoring
parameters and all active alarms.

The Comms Board is equipped with a modem interface for remote reporting of the present switch status
information, alarm history information and the history of status screens that are triggered upon a major alarm
event. The monitoring system software also supports an auto-dial feature that allows the system to automatically
dial programmed phone numbers by way of a modem to report designated alarm conditions.

Programming the Comms Board is performed through the touchscreen. See Comm Options on page 105 for
details.

See Figures 47 and 48 for the location of the Comms Board. See Figure 52 for information on the control wiring.

6.4 Liebert IntelliSlot™ Web/485 Card With Adapter

A Liebert IntelliSlot Web/485 Card With Adapter (IS-WEB485ADPT) enables the Liebert STS2/PDU to
communicate to a network management system (NMS). The card provides the internal hardware and software to
communicate, via SNMP, to any I.P.-based Ethernet network through an RJ-45 connector using Category 5
cabling.

The Liebert IS-WEB485ADPT provides redundant paths for communications that make it possible to connect to
a Building Management System (BMS) using Modbus, while simultaneously communicating to a NMS through
SNMP. A terminal block provides the connection to Modbus.

See Figures 47 and 48 for the location of the Liebert IntelliSlot Web/485 Card With Adapter. See Figure 53 for
control wiring information.

If you have questions about the Liebert IS-WEB485ADPT, refer to the user guide SL-52615, available at Vertiv’s
Web site, www.vertivco.com

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 15

6.5 Remote Source Selection

The Remote Source Selection allows the preferred input source to be chosen from a remote location. A user
supplied normally open dry contact allows the user to remotely select a source to be the preferred source in the
same process as the local source transfer selection.

If both the input contacts are closed, the current selected preferred source shall be retained. If the unit’s
preferred source selection and Remote Source Selection are active at the same time,
the Liebert STS2/PDU follows the last request for a preferred source change, regardless of whether it was from
the local or Remote Source Selection controls.

See 10.3 - Enabling Remote Source Selection for instructions on enabling the Remote Source Selection.

See Figures 47 and 48 for the location of the Remote Source Selection option.

See 4.4 - Remote Source Selection Wiring and Figure 55 for information on the control wiring.

6.6 Key Lockout Switch

The key lockout switch activates a software lockout of the touchscreen to prevent manual transfers and
configuration changes. When locked out, the touchscreen becomes a read-only display. A key is needed to do
manual transfers or change settings.

The alarm silence button is not disabled when in the lockout position.

The switch is located on the front of the unit next to the display; it is behind the front door but can be operated
without opening the front door. See Figures 20 through 22 for the key lockout switch location on each unit.

See 13.2.1 - Security and Figure 64 for instructions on using the key lockout switch.

6.7 Static Switch Redundant Output Breaker

A plug-in, non-automatic circuit breaker is provided which allows redundancy in the static switch output power
path. The breaker is connected in parallel with the static switch output plug-in non-automatic circuit breaker.

6.8 Inline Panelboards

An output distribution cabinet with either Square D or General Electric inline panelboards with copper bus to
accept bolt-in or plug-in circuit breakers. Each panelboard is individually protected by a 225A, 3-pole panelboard
main circuit breaker.

Each panelboard includes a separate isolated neutral bus bar and a safety-ground bus bar for the neutral and
safety-ground connections for at least 42 output circuits.

6.9 I-Line Panelboards

An output distribution cabinet with one vertically mounted Square D I-Line panelboard with copper bus to
accept Square D three phase plug-in circuit breakers. The panelboard must be enclosed with an accent cover.

6.10 Subfeed Breakers

Breakers for feeding remote panelboard(s) or other loads. Available in ratings of 225A or 400A.

NOTE

Only available on units with inline panelboards. 400A breaker not available on 250A units.

6.11 K-Factor Transformers

U.S. Department of Energy compliant K20-rated double-shielded copper isolation transformer specially designed
to accommodate highly nonlinear loads in accordance with UL 1561 (in place of standard isolation transformer).

6.12 Surge Suppression System

A fused and monitored high-energy, 80 kAmp/phase surge suppression system by Control Concepts connected
to each input of the unit for superior surge suppression.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 16

7.0 INSTALLATION DRAWINGS

22.8"

(579.1mm)

Air Intake

Air Intake Area
Do not block air
filter, typical

See Detail A

PSP11200
Rev. 4

Bottom Power
Conduit Entry
Area 14.8" x 10.4"
(375.9 x 264.2mm)

Top Power Conduit
Entry Area 24.4" x 9.4"
(619.8 x 238.8mm)

2.75" (69.8mm)
Typical

Stabilizing Foot

1. 18" (457mm) clearance above unit required for air exhaust

2. Installation and service access required in front only.

3. Approximate heat output: 11,737 BTU/Hr (3.44 kW).

4. Approximate weight: 3393 lb. (1542 kg)

5. Unit bottom is structurally adequate for forklift handling.

6. Keep cabinet within 15 degrees of vertical while handling.

7. Color: IBM off-white

8. Open door to replace air filter, disposable type,
size: 1"x25"x25" (25 x 635x635mm)

9. Threaded mounting holes (see Detail A) are provided for seismic
anchoring or floor stand. Mounting bolts must be threaded into the
unit mounting holes from underneath the unit base. If a floor stand
is used, the casters must rest on the floor stand to support the unit's weight.

10. Top and bottom cable entry available through removable access plates.
Remove, punch to suit conduit size and replace.

12mm Diameter
Threaded Mounting
Hole; 4 typically
See Note 9

Hinged Access Panel
To Input Breakers

Air Exhaust

120° Front Door Swing
All doors with
lift-off hinges

2.8" (71.1mm)

Top Control Conduit
Entry Area 12.8" x 5.1"
(325.1 x 129.5mm)

1.1"

(27.9mm)

Bottom Control
Conduit Entry
Area 11" x 4.6"
(279.4 x 116.8mm)

Front

8.4"

(213.6mm)

8.8"

(223.5mm)

5.6"

(142.2mm)

5.8"

(147.3mm)

TOP

RIGHT SIDE

FRONT

BOTTOM

Detail A

(Front of Unit

Shown without Side Panel)

1.1"

(28mm)

77.6"

(1971mm)

32.3" (820mm)

60.9 (1547mm)

Figure 7 Outline drawing, 250A Liebert STS2/PDU

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 17

Figure 8 Outline drawing, 250A Liebert STS2/PDU with right side I-Line distribution

A

76.8 (1950mm)

77.6

(1970mm)

ir Intake Area
Do not block air
filter, typical

2.8" (71mm)

Top Input Power
Conduit Entry Area

24.4" x 9.4"
(620 x 239mm)

Top Control Conduit
Entry Area 12.8" x 5.1"
(325 x 130mm)

1.18" (457mm) clearance above unit required for air exhaust

2. Installation and service access required in front only.

3. Heat output: Approx. 11,737 BTU/hr (3.44kW).

4. Approximate weight: 3993 lb. (1815 kg).

5. Unit bottom is structurally adequate for forklift handling.

6. Keep cabinet within 15 degrees of vertical while handling.

7. Color: IBM off-white

8. Open door to replace air filter, disposable type, size: 1" x 25" x 25"
(25 x 635 x 635mm).

9. Threaded mounting holes (see Detail A) are provided for seismic
anchoring or floor stand. Mounting bolts must be threaded into unit mounting
holes from underneath unit base. If a floor stand is used, the casters must rest
on the floor stand to support the unit’s weight.

10. Top and bottom cable entry available through removable
access plates. Remove, punch to suit conduit size and replace.

FRONT

1.1"

(27.9mm)

Top Output
Conduit Entry Area
(2) 13.1" x 7.9"
(333 x 201mm)

5.6"

(142.2mm)

TOP

Air Exhaust

120° Front Door Swing
All doors with
lift-off hinges

Bottom Input Power
Conduit Entry
Area 14.8" x 10.4"
(376 x 264mm)

PSP11206

32.3" (820mm)

RIGHT SIDE

1.8" (46mm)

2.3"

(58mm)

Hinged Access Panel
To Input Breakers

12mm Diameter
Threaded Mounting
Hole; 4 typically
See Note 9

8.4"

(214mm)

(147mm)

8.8"

(224mm)

5.8"

1.1"

(28mm)

2.75"
(69.8mm)
Typical

Detail A

(Front of Unit

Shown without Side Panel)

Front

Bottom Control
Conduit Entry
Area 11" x 4.6"
(279.4 x 116.8mm)

See Detail A

BOTTOM

(101.6mm)

Stabilizing
Foot

Bottom Output
Conduit Entry Area
(2) 12.5" x 7.2"
(318 x 183mm)

Air
Intake

4"

26"

(660mm)

2.6" (66mm)

Rev. 2

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 18

Figure 9 Outline drawing, 250A Liebert STS2/PDU with right side inline distribution

76.8 (1950mm)

Air Intake Area
Do not block air
filter, typical

2.8" (71mm)

Top Input Power
Conduit Entry Area

24.4" x 9.4"
(620 x 239mm)

Top Control Conduit
Entry Area 12.8" x 5.1"
(325 x 130mm)

1. 18" (457mm) clearance above unit required for air exhaust

2. Installation and service access required in front only.

3. Heat output: approx. 11,737 BTU/hr (3.44kW).

4. Approximate weight: 3993 lb. (1815 kg).

5. Unit bottom is structurally adequate for forklift handling.

6. Keep cabinet within 15 degrees of vertical.

7. Color: IBM off-white

8. Open door to replace air filter, disposable type, size:
1" x 25" x 25" (25 x 635 x 635mm).

9. Threaded mounting holes (see Detail A) are provided
for seismic anchoring or floor stand. Mounting bolts
must be threaded into unit mounting holes from
underneath unit base. If a floor stand is used, the
casters must rest on the floor stand to support the
unit's weight.

10. Top and bottom cable entry available through removable
access plates. Remove, punch to suit conduit size and replace.

FRONT

1.1"
(27mm)

22.8"

(579mm)

5.6"

(142.2mm)

Air Exhaust

TOP

120° Front Door Swing
All doors with lift-off hinges

Bottom Input
Power Conduit
Entry Area

14.8" x 10.4"
(376 x 264mm)

77.6

(1970mm)

2.1"

(53mm)

Hinged Access
Panel to Input
Breakers

(213mm)

(223.5mm)

PSP11207
Rev. 2

32.3" (820mm)

RIGHT SIDE

12mm Diameter
Threaded Mounting
Hole; 8 typically
See Note 9

1.7"

(43mm)

8.4"

5.8"

(223.5mm)

1.1"

(28mm)

8.8"

12.5"

(318mm)

0.88" Diameter
Typically 42 Places

Detail B

Detail A

(Front of Unit

Shown without Side Panel)

Bottom Control
Conduit Entry
Area 11" x 4.6"

Front

(279 x 117mm)

See Detail A

BOTTOM

2.6" (66mm)

2.75"
(69.8mm)
Typical

Air
Intake

8.1"

(206mm)

Stabilizing
Foot

Bottom Output
Subfeed Conduit
Entry Area
Typically 2 Places

8.3" x 4"
(211 x 102mm)

Bottom Output
Conduit Entry Area
Typically 2 Places
See Detail B

7.1" (180mm)

5.1" (130mm)

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 19

Figure 10 Outline drawing, 250A Liebert STS2/PDU with left side I-Line distribution

32.3" (820mm)

LEFT SIDE

1.8" (46mm)

2.3" (58mm)

Top Input Power
Conduit Entry Area

24.4" x 9.4"
(620 x 239mm)

77.6

(1970mm)

Top Output
Conduit Entry Areas
(2) 13.1" x 7.9"
(333 x 201mm)

Air Intake Area
Do not block air
filter, typical

1.1"

(27.9mm)

76.8 (1950mm)

33.7" (856mm)

FRONT

12mm Diameter
Threaded Mounting
Hole; 4 typically
See Notes 8 and 9

Air
Exhaust

2.75"
(69.8mm)
Typical

Stabilizing
Foot

Detail A

(Front of Unit

Shown without Side Panel)

Top Control Conduit
Entry Area 12.8" x 5.1"
(325 x 130mm)

38.7" (983mm)

5.6"

(142mm)

TOP

1. 18" (457mm) clearance above unit required for air exhaust

2. Installation and service access required in front only.

3. Heat output, approximately 11,737 BTU/Hr (3.44kW).

4. Approximate weight: 3993 lb. (1815 kg).

5. Unit bottom is structurally adequate for forklift handling.

6. Keep cabinet within 15 degrees of vertical.

7. Color: IBM off-white

8. Open door to replace air filter, disposable type, size: 1" x 25" x 25"
(25 x 635 x 635mm).

9. Threaded mounting holes (see Detail A) are provided for seismic
anchoring or floor stand. If a floor stand is used, the casters
must rest on the floor stand to support the unit’s weight.

10. Top and bottom cable entry available through removable
access plates. Remove, punch to suit conduit size and replace.

Bottom Output
Conduit Entry Area
(2) 12.5" x 7.2"
(318 x 183mm)

Hinged Access Panel
To Input Breakers

120° Front Door Swing
All doors with
lift-off hinges

26"

(660mm)

2.6" (66mm)

4" (102mm)

Bottom Input Power
Conduit Entry
Area 14.8" x 10.4"
(376 x 264mm)

24.2"

(615mm)

24.7"

5.8"

(147mm)

(27.9mm)

(627mm)

PSP11202
Rev. 2

Front

1.1"

BOTTOM

Bottom Control
Conduit Entry
Area 11" x 4.6"
(279.4 x 116.8mm)

See Detail A

Air
Intake

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 20

Figure 11 Outline drawing, 250A Liebert STS2/PDU with left side Inline distribution

0.88" Diameter
Typically 42 Places

PSP11203
Rev. 2

1.1"

(27.9mm)

1.1"
(27.9mm)

38.7" (983mm)

Bottom Input Power Conduit
Entry Area 14.8" x 10.4"
(376 x 264mm)

Bottom Output
Subfeed Conduit
Entry Area
Typically 2 Places

8.3" x 4"
(211 x 102mm)

Bottom Output
Conduit Entry Area
Typically 2 Places
See Detail B

Air Intake Area
Do not block air
filter, typical

Air
Exhaust

Air
Intake

See Detail A

Top Input Power
Conduit Entry Area

24.4" x 9.4"
(620 x 239mm)

2.75"
(69.8mm)
Typical

Stabilizing
Foot

1.18" (457mm) clearance above unit required for air exhaust

2. Installation and service access required in front only.

3. Heat output approximately 11,737 BTU/hr (3.44kw).

4. Approximate weight: 3993 lb. (1815 kg).

5. Unit bottom is structurally adequate for forklift handling

6. Keep cabinet within 15 degrees of vertical.

7. Color: IBM off-white

8. Open door to replace air filter, disposable type, size:
1" x 25" x 25" (25 x 635 x 635mm).

9. Threaded mounting holes (see Detail A) are provided for
seismic anchoring or floor stand. If a floor stand is used,
the casters must rest on the floor stand to support the unit’s
weight.

10. Top and bottom cable entry available through removable
access plates. Remove, punch to suit conduit size and replace.

12mm Diameter
Threaded Mounting
Hole; 4 typically
See Note 9

Hinged Access
Panel to Input
Breakers

120° Front Door Swing
All doors with
lift-off hinges

Top Control Conduit
Entry Area 12.8" x 5.1"
(325 x 130mm)

Bottom Control
Conduit Entry
Area 11" x 4.6"
(279 x 117mm)

8.1"

(206mm)

12.5"

(318mm)

24.7"
(627mm)

2.6"
(66mm)

5.1"

(130mm)

24.2"

(615mm)

5.8"

(147mm)

5.6"

(142mm)

TOP

LEFT SIDE

Front

7.1" (180mm)

FRONT

BOTTOM

Detail A

(Front of Unit

Shown without Side Panel)

32.3" (820mm)

76.8 (1950mm)

77.6

(1970mm)

1.7"

(43mm)

2.1"

(53mm)

33.7"

(856mm)

Detail B

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 21

Front

3

.3

9.4"

(239mm)

11.5" (292mm)

2.3"
(58.4mm)

2.3"

1. Approximate weight: 400A - 4608 lb. (2095kg)
600A - 5692 lb. (2582kg).

2. 18" (457mm) clearance above unit required for
air exhaust.

3. Installation and service access required in
front and right side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output:
400A - 19,295 BTU/hr (5.66 kW)
600A - 29,238 BTU/hr (8.57 kW).

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter. Disposable type, size
1 x 25 x 25 (25 x 635 x 635mm).

9. Top and bottom cable entry available through
removable access plates. Remove, punch to suit
conduit size and replace.

0.88" Diameter
Typically 42 Places

PSP11400
Rev. 3

11. 2"

(284mm)

Bottom Input Power Conduit
Entry Area, typically 2

10.4" x 5.4" (264 x 137mm)

Bottom Subfeed
Conduit Entry Area
Typically 2 Places

8.3" x 4"
(211 x 102mm)

Air Intake Area
Do not block air filter

Top Input Power
Conduit Entry Area

21.4" x 7" (620 x 239mm)

Hinged Access
Panel to Input
Breakers

120° Front Door Swing
All doors with lift-off hinges

Top Control
Conduit Box
Entry Area

12.9" x 6.8"

(325 x 130mm)
See Drawing
PSP13401

Bottom Control
Conduit Entry
Area 8.7" x 5.5"
(221 x 140mm)

Bottom Output
Conduit Entry
Area, Typically 4
Places; See Detail A

BOTTOM

28.3"

(719mm)

22.7"

(577mm)

20.4"

(518mm)

4.9"

(124mm)

13.6"

(345mm)

TOP

RIGHT SIDE

7.2" (183mm)

7" (178mm)

FRONT

Detail A

49.4"

(1255mm)

23.9"

(606mm)

73.3" (1861mm)

77.4"

(1966mm)

1.9" (48mm)
Typical

4.4"

(112mm)

Figure 12 Outline drawing,400-600A Liebert STS2/PDU with right side inline distribution

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 22

Figure 13 Outline drawing, 400-600A Liebert STS2/PDU with right side output breaker or I-Line distribution

1.9"

(48mm)

2

.3

2

.

3

1.4

1.8'

(46mm)

9.4"

(239mm)

Air Exhaust

Bottom Output
Conduit Entry
Area, 2 Places

21.3" x 8.3"
(541 x 211mm)

Front

11.5" (292mm)

11. 2"

(284mm)

1. Approximate weight: 400A - 4608 lb. (2095kg)
600A - 5692 lb. (2587kg).

2. 18" (457mm) clearance above unit required for
air exhaust.

3. Installation and service access required in
front and right side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output:
400A - 19,295 BTU/hr (5.66 kW)
600A - 29,238 BTU/hr (8.57 kW).

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter. Disposable
type size 1 x 25 x 25 (25 x 635 x 635mm).

9. Top and bottom cable entry available through
removable access plates. Remove, punch to suit
conduit size and replace.

PSP11401
Rev. 2

Bottom Input Power Conduit
Entry Area, Typically 2

10.4" x 5.4" (264 x 137mm)

Bottom Control
Conduit Entry Area

8.7" x 5.5"
(221 x 140mm)

Air Intake Area
Do not block air filter.

Top Input Power
Conduit Entry Area

21.4" x 7" (54x 178mm)

120° Front Door Swing
All doors with lift-off hinges

Top Control
Conduit Box

12.9" x 6.8"
(325 x 130mm)
See Drawing
PSP13401

BOTTOM

43.6"
(1107mm)

17.2"

(437mm)

20.4"

(518mm)

28.3"

(719mm)

TOP

RIGHT SIDE

FRONT

49.4"

(1255mm)

23.9"

(606mm)

73.3" (1861mm)

77.4"

(1966mm)

4.4"

(112mm)

22.7"

(577mm)

3.3"

(84mm)

Top Output
Conduit Entry
Area, 2 Places

21.9" x 8.8"
(556 x 224mm)

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 23

Figure 14 Outline drawing, 400-600A Liebert STS2/PDU with left side inline distribution

BOTTOM

TOP

3.3"

(84mm)

4.4"
(112mm)

FRONT

7.2"

(182.9mm)

7"
(178mm)

13.6"

(345mm)

2.3

39.6"

(1006mm)

11.5"

DETAIL A

.88" DIA.

Typ. 42 Places

1.9" (48mm)
Typical

2.3" (58mm)

4.9"

(124mm)

1.8'
(46mm)

8"

(203mm)

28.3"

(719mm)

22.7"

(577mm)

18.9"

(480mm)

Air Exhaust

Bottom Input
Power Conduit
Entry Area,
2 Places

10.4" x 5.4"
(264 x 137mm)

1. Approximate weight: 400A - 4608 lb. (2095kg)
600A - 5692 lb. (2587kg).

2. 18" (457mm) clearance above unit required for
air exhaust.

3. Installation and service access required in
front and left side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output:
400A - 19,295 BTU/hr (5.66 kW)
600A - 29,238 BTU/hr (8.57 kW).

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter. Disposable
type size 1 x 25 x 25 (25 x 635 x 635mm).

9. Top and bottom cable entry available through
removable access plates. Remove, punch to suit
conduit size and replace.

PSP11402
Rev. 2

Bottom Control Conduit
Entry Area, 8.7" x 5.5"
(221 x 140mm)

Air Intake Area
Do not block air filter.

Bottom Subfeed
Conduit Entry Area

8.3" x 4" (211 x 102mm)

120° Front Door Swing
All doors with lift-off hinges

Top Control
Conduit Box

12.9" x 6.8"
(325 x 130mm)
See Drawing
PSP13401

Top Input Power
Conduit Entry Area

21.4" x 7"
(544 x 178mm)

17.2"

(437mm)

LEFT SIDE

FRONT

49.4"

(1255mm)23.9"

(606mm)

73.3" (1861mm)

77.4"

(1966mm)

Bottom Output
Conduit Entry
Area, 4 Places
See Detail A

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 24

Figure 15 Outline drawing, 400-600A Liebert STS2/PDU with left side output breaker or I-Line distribution

Front

1.4"

(36mm)

1.9" (48mm)

3.3"

(84mm)

18.9"

(480mm)

1.8'
(46mm)

8"

(203mm)

39.6" (1006mm)

Air Exhaust

Bottom Output
Conduit Entry
Area, 2 Places

21.3" x 8.3"
(541 x 211mm)

11. 5"

(292mm)

1. Approximate weight: 400A - 4608 lb. (2095kg)
600A - 5692 lb. (2587kg).

2. 18" (457mm) clearance above unit required for
air exhaust.

3. Installation and service access required in
front and left side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output:
400A - 19,295 BTU/hr (5.66 kW)
600A - 29,238 BTU/hr (8.57 kW).

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter. Disposable
type, size 1 x 25 x 25 (25 x 635 x 635mm).

9. Top and bottom cable entry available through
removable access plates. Remove, punch to suit
conduit size and replace.

PSP11403
Rev. 2

Bottom Input
Power Conduit
Entry Area
Typically 2

10.4" x 5.4"
(264 x 137mm)

Bottom Control Conduit Entry Area

8.7" x 5.5" (221 x 140mm)

Air Intake Area
Do not block air filter

Top Input Power Conduit
Entry Area 21.4" x 7"
(54x 178mm)

120° Front Door Swing
All doors with lift-off hinges.

Top Control Conduit Box Entry
Area 12.9" x 6.8" (325 x 130mm)
See Drawing PSP13401

BOTTOM

43.6"

(1107mm)

17.2"

(437mm)

28.3"

(719mm)

2.3" (58mm)

2.3" (58mm)

TOP

LEFT SIDE

FRONT

49.4"

(1255mm)

23.9"

(606mm)

73.3" (1861mm)

77.4"

(1966mm)

4.4"

(112mm)

22.7"

(577mm)

Top Output
Conduit Entry
Area, 2 Places

21.9" x 8.8"

(556 x 224mm)

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 25

Figure 16 Outline drawing, 800A Liebert STS2/PDU with right side output breaker or I-Line distribution

77.4"

(1966mm)

Air Intake Area
Do not block air filter.
Typical

39.9" (1013mm)
Shipping Split

96.9" (2461mm)

FRONT

57" (1448mm)

Shipping Split

Hinged Access Panel

49.4"

(1255mm)

RIGHT SIDE

Top Output
Conduit Entry
Area (2)

21.9" x 8.8
(553 x 224mm)

Top Control
Conduit Entry Area
9" x 7.1"
(229 x 180mm)

2.7"

(69mm)

Bottom Control
Conduit Entry
Area 21" x 10"
(533 x 254mm)

PSP11800
Rev. 1

2.9"

(74mm)

1.4" (36mm)

32.3" (820mm)

120° Front Door Swing
All doors with lift-off hinges

54" (1372mm)

14.2"

(361mm)

(97mm)

Front

3.8"

TOP

3.8"

(97mm)

BOTTOM

Top Input Power
Conduit Entry Area

23.2" x 5.5"
(589 x 140mm)

Bottom Input
Power Conduit
Entry Area,
21" x 10" (533 x 254mm)

2.3"

(58mm)

2.9"

(74mm)

1.4"

(36mm)

Bottom Output
Power Conduit
Entry Area, 2

21.3" x 8.3"
(541 x 211mm)

2.3"

(58mm)

1. Approximate weight: 8618 lb. (3917kg)

2. 18" (457mm) clearance above unit
required for air exhaust.

3. Installation and service access required
in front and right side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output:
39,238 BTU/hr (11.5 kW)

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter. Disposable
type size 1 x 25 x 25 (25 x 635 x 635mm).

9. Top and bottom cable entry available through
removable access plates. Remove, punch
to suit conduit size and replace.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 26

Figure 17 Outline drawing, 800A Liebert STS2/PDU with right side inline distribution

2.3"

2.3"

2.7" (69mm)

DETAIL A

7"
(178mm)

0.88 " Diameter
Typically 42 Places

13.6"

(345mm)

Front

1. Approximate weight: 8618 lb. (3917kg)

2. 18" (457mm) clearance above unit required for
air exhaust.

3. Installation and service access required in
front and right side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output: 39,238 BTU/hr (11.5 kW)

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter. Disposable type size
1 x 25 x 25 (25 x 635 x 635mm).

9. Top and bottom cable entry available through
removable access plates. Remove, punch to suit
conduit size and replace.

PSP11801
Rev. 1

Bottom Output
Conduit Entry
Area, Typical (4)
Places; See
Detail A

Bottom Subfeed Conduit
Entry Area, Typical 2
Places 8.3" x 8.3"
(211 x 102mm)

Air Intake Area
Do not block air filter.
Typical

Top Input Power
Conduit Entry Area

23.2" x 5.5" (589 x 140mm)

Hinged Access Panel

120° Front Door Swing
All doors with lift-off hinges

Top Control
Entry Area
9" x 7.1"
(229 x 180mm)

BOTTOM

7.2"
(183mm)

4.9"

(124mm)

3.8"

(97mm)

3.8"

(97mm)

2.9"

(74mm)

1.4" (36mm)

1.9" (48mm)
Typical

14.2"

(361mm)

54" (1372mm)

32.3" (820mm)

TOP

RIGHT SIDE

FRONT

49.4"

(1255mm)

96.9" (2461mm)
57" (1448mm)

Shipping Split

39.9" (1013mm)
Shipping Split

77.4"

(1966mm)

Bottom Input Power Conduit
Entry Area,
21" x 10" (533 x 254mm)

Bottom Control
Conduit Entry
Area 21" x 10"
(533 x 254mm)

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 27

Figure 18 Outline drawing, 800A Liebert STS2/PDU with left side output breaker or I-Line distribution

Front

1. Approximate weight: 8618 lb. (3917kg)

2. 18" (457mm) clearance above unit
required for air exhaust.

3. Installation and service access required in
front and left side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output: 39,238 BTU/hr
(11.5 kW)

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter.
Disposable type size 1 x 25 x 25
(25 x 635 x 635mm).

9. Top and bottom cable entry available
through removable access plates.
Remove, punch to suit conduit size
and replace.

PSP11802
Rev. 1

Bottom Output
Conduit Entry
Area, 2 Places

21.3" x 8.3"
(541 x 211mm)

Air Intake Area
Do not block air filter.
Typical

Top Input Power
Conduit Entry Area

23.2" x 5.5"
(589 x 140mm)

Hinged
Access Panel

120° Front Door Swing
All doors with lift-off hinges

Top Control
Conduit Entry
Area 9" x 7.1"
(229 x 180mm)

Bottom Control
Conduit Entry
Area 21" x 10"
(533 x 254mm)

BOTTOM

2.3"

(58mm)

2.3"

(58mm)

2.9"

(74mm)

3.8"

(97mm)

3.8"

(97mm)

2.9" (74mm)

18.3"

(465mm)

1.4" (36mm)

14.2"

(361mm)

54" (1372mm)

41.9"

(1064mm)

TOP

LEFT SIDE

FRONT

49.4"

(1255mm)

96.9" (2461mm)

57" (1448mm)

Shipping Split

39.9" (1013mm)
Shipping Split

77.4"

(1966mm)

Top Output
Conduit Entry
Area (2)

21.9" x 8.8
(553 x 224mm)

Bottom Input Power
Conduit Entry Area,
21" x 10" (533 x 254mm)

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 28

Figure 19 Outline drawing, 800A Liebert STS2/PDU with left side inline distribution

A

49.4"

(1255mm)

57" (1448mm)

Shipping Split

77.4"

(1966mm)

96.9" (2461mm)

39.9" (1013mm)
Shipping Split

Bottom Subfeed
Conduit Entry Area,
Typical 2 Places 8.3" x 4"
(211 x 102mm)

Bottom Output
Conduit Entry
Area, Typical 4
Places; See
Detail Area A

7.2" (183mm)

Top Control
Conduit Entry

rea 9" x 7.1"

(229 x 180mm)

LEFT SIDE

Bottom Input
Power Conduit
Entry Area,
21" x 10"
(533 x 254mm)

1.9" Typ.

2.3"

4.9"

(124mm)

2.3" (58mm)

2.9"

(74mm)

Air Intake Area
Do not block air filter.
Typical

3.8"

(97mm)

BOTTOM

54" (1372mm)

Front

3.8"

(97mm)

Hinged
Access
Panel

FRONT

13.6"

(345mm)

7"
(178mm)

14.2"

(361mm)

0.88 " Diameter
Typically 42 Places

DETAIL A

Bottom Control
Conduit Entry
Area 21" x 10"
(533 x 254mm)

1. Approximate weight: 8618 lb. (3917kg)

2. 18" (457mm) clearance above unit required for
air exhaust.

3. Installation and service access required in
front and left side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output: 39,238 BTU/hr
(11.5 kW)

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter. Disposable
type size 1 x 25 x 25 (25 x 635 x 635mm).

9. Top and bottom cable entry available through
removable access plates. Remove, punch
to suit conduit size and replace.

18.3"

(465mm)

2.7"

(69mm)

120° Front Door Swing

TOP

All doors with lift-off hinges

41.9"

(1064mm)

Top Input Power Conduit
Entry Area 23.2" x 5.5"
(589 x 140mm)

PSP11803
Rev. 0

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 29

Figure 20 Outline drawing, 250A Liebert STS2/PDU with key lockout switch option

A

80.9" (1547mm)

Key

Lockout

Switch

77.6"

(1970mm)

32.3" (820mm)

ir Intake Area
Do not block air
filter. Typical

2.8" (71mm)

Top Power Conduit
Entry Area

24.4" x 9.4"
(620 x 239mm)

Top Control Conduit
Entry Area 12.8" x 5.1"
(325 x 130mm)

1. 18" (457mm) clearance above unit required

for air exhaust.

2. Installation and service access required in front only.

3. Approximate heat output: 11,737 BTU/Hr (3.44 kW).

4. Approximate weight: 3393 lb. (1542 kg).

5. Unit bottom is structurally adequate for forklift handling.

6. Keep cabinet within 15 degrees of vertical.

7. Color: IBM off-white

8. Open door to replace air filter. Disposable type,

size, 1" x 25" x 25" (25 x 635 x 635mm).

9.Threaded mounting holes (see Detail A) are provided for seismic

anchoring or floor stand. Mounting bolts must be threaded into the unit

from underneath the unit base. If a floor stand is used, the casters

must rest on the floor stand to support the weight of the unit.

10. Top and bottom cable entry available through removable

access plates. Remove, punch to suit conduit size and replace.

FRONT

22.8"

(579mm)

1.1" (27.9mm)

5.6"

(142mm)

TOP

120° Front Door
Swing; All doors with
lift-off hinges

RIGHT SIDE

12mm Diameter

Air
Exhaust

Bottom Power
Conduit Entry
Area

14.8" x 10.4"
(376 x 264mm)

Threaded Mounting
Hole; 4 typically
See Note 9

Hinged Access Panel
To Input Breakers

8.4"

(213mm)

5.8"

(147mm)

8.8"

(224mm)

Detail A

(Front of Unit

Shown without Side Panel)

Bottom Control
Conduit Entry

Front

1.1"

(27.9mm)

Area 11" x 4.6"
(279 x 117mm)

See Detail A

BOTTOM

PSP11201
Rev. 3

2.75"
(69.8mm)
Typical

Stabilizing
Foot

Air
Intake

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 30

Figure 21 Outline drawing, 400-600A Liebert STS2/PDU, inline distribution, right side with key lockout switch option

49.4"

(1255mm)

Key

Lockout

Switch

(1966mm)

77.4"

73.3" (1861mm)

23.9"

(606mm)

Air Intake Area
Do not block air filter.

1. Approximate weight: 400A - 4608 lb. (2095kg)
600A - 5692 lb. (2587kg)

2. 18" (457mm) clearance above unit required for
air exhaust.

3. Installation and service access required in
front and right side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output:
400A - 19,295 BTU/hr (5.66 kW)
600A - 29,238 BTU/hr (8.57 kW)

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter. Disposable type,
size 1 x 25 x 25 (25 x 635 x 635mm).

9. Top and bottom cable entry available through
removable access plates. Remove, punch to suit
conduit size and replace.

0.88 " Diameter
Typically 42 Places

FRONT

13.6"

(345mm)

7"
(178mm)

DETAIL A

Bottom Control
Conduit Entry
Area 8.7" x 5.5"
(221 x 140mm)

PSP11407
Rev. 2

Top Control
Conduit Box
Entry Area

12.9" x 6.8"
(328 x 173mm)
See Drawing
PSP13401

Air Exhaust
120° Front Door Swing
All doors with lift-off hinges

11. 2"

20.4"

(518mm)

22.7"

(577mm)

(284mm)

4.4"

(112mm)

(719mm)

BOTTOM

11.5" (292mm)

9.4"
(239mm)

3.3"

(84mm)

28.3"

RIGHT SIDE

Top Input Power Conduit
Entry Area 21.4" x 7"
(544 x 178mm)

TOP

Front

Bottom Input Power Conduit
Entry Area, Typically 2

10.4" x 5.4" (533 x 254mm)

4.9"

(124mm)

Hinged Access
Panel

Bottom Subfeed
Conduit Entry Area,
Typical 2 Places

8.3" x 4"
(211 x 102mm)

Bottom Output
Conduit Entry
Area, Typical 4
Places; See
Detail Area A

1.9" (48mm)

7.2" (183mm)

2.3"

2.3"

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 31

Figure 22 Outline drawing, 800A Liebert STS2/PDU, inline distribution, right side with key lockout switch option

Key

Lockout

Switch

(1966mm)

77.4"

39.9" (1013mm)
Shipping Split

96.9" (2461mm)
57" (1448mm)

Shipping Split

49.4"

(1255mm)

Air Intake Area
Do not block air filter.
Typical

Top Control
Conduit Entry
Area 9" x 7.1"
(229 x 180mm)

2.7" (69mm)

0.88 " Diameter
Typically 42 Places

2.9"
(74mm)

1.4" (36mm)

32.3" (820mm)

120° Front Door Swing
All doors with lift-off hinges

13.6"

(345mm)

7"
(178mm)

DETAIL A

Bottom Control
Conduit Entry
Area 21" x 10"
(533 x 254mm)

FRONT

TOP

14.2"

(361mm)

(97mm)

Top Input Power Conduit
Entry Area 23.2" x 5.5"
(589 x 140mm)

54" (1372mm)

Front

3.8"

Hinged Access Panel

3.8"

(97mm)

BOTTOM

RIGHT SIDE

1. Approximate weight: 8618 lb. (3917kg)

2. 18" (457mm) clearance above unit
required for air exhaust.

3. Installation and service access required in
front and right side only.

4. Keep cabinet within 15 degrees of vertical.

5. Color - IBM off-white.

6. Approximate heat output: 39,238 BTU/hr
(11.5 kW)

7. Unit bottom is structurally adequate for
forklift handling.

8. Open doors to replace air filter. Disposable
type, size 1 x 25 x 25 (25 x 635 x 635mm).

9. Top and bottom cable entry available through
removable access plates. Remove, punch
to suit conduit size and replace.

Bottom Input Power
Conduit Entry Area,
21" x 10" (533 x 254mm)

Bottom Subfeed
Conduit Entry Area,
Typical 2 Places

8.3" x 4"
(211 x 102mm)

Bottom Output
Conduit Entry
Area, Typical 4
Places; See
Detail Area A

1.9" (48mm) Typical

7.2" (183mm)

2.3" (58mm)

2.3"

4.9"

(124mm)

PSP11807
Rev. 1

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 32

Figure 23 Electrical field connections, 250A Liebert STS2/PDU input/output with CB8

FRONT

Doors and Accent Panels

Not Shown

CB5

A

B

C

A

B

C

A

B

C

.51" DIA.

(13mm)

Typ. 4 Places

Neutral
Output
Busbar

See Ground
Busbar Detail B

CB8

CB3

See Source,
Neutral, and
Output Busbar
Detail A

CB4

CB1

Output

Source 1

Source 2

CB6

CB7

CB2

1. Phase, neutral and ground busbars are 1/4" thick.

2. Control wiring and power wiring must be run in separate conduit.
Output cables should be run in a separate conduit from input cables.

3. Aluminum and copper clad aluminum cables are not recommended.

4. All wiring is to be in accordance with national and local electrical codes

Source 1 Busbar
Approx. 7.5 X 3.2
(191 x 81mm)
1/2"-13 PEM Nut
Typ. 4 Places

Output Busbar
Approx. 7.5" x 3.2"
(191 x 81mm)
1/2"-13 PEM Nut
Typ., 4 Places

Neutral Output
Busbar

12.6 X 5.75
(320 x 146mm)
1/2"-13 PEM Nut
Typ. 10 Places

Source 2 Busbar
Approx. 7.5 X 3.2
(191 x 81mm)
1/2"-13 PEM Nut
Typ. 4 Places

SOURCE, NEUTRAL,

& OUTPUT

BUSBAR DETAIL A

GROUND BUSBAR

DETAIL B

PSP11009
Rev. 0

1.75"
(44mm)
Typical

1.75" (44mm)

1.77"

(45mm)

8" (203mm)

3.5"
(89mm)

1.75"

(44mm)

Typical

1.75"

(44mm)

Typical

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 33

Figure 24 Electrical field connections, 250A Liebert STS2/PDU input with CB3

See Source
Busbar
Detail A

CB1

CB4

CB3

Source 1

Source 2

CB6

CB7

(44mm)

CB2

CB5

1.75"

Typical

A

A

B

B

C

Source 1 Busbar
Approx. 7.5 x 3.2
(191 x 81mm)
1/2"-13 PEM Nut
Typ. 4 Places

No Customer

Connections

See Ground
Busbar Detail B

Doors and Accent Panels

FRONT

Not Shown

8" (203mm)

1.77"

(45mm)

.51" DIA.

(13mm)

Typ. 4 Places

GROUND BUSBAR

DETAIL B

1.75" (44mm)

1. Phase, neutral and ground busbars are 1/4" thick.

2. Control wiring and power wiring must be run
in separate conduit. Output cables should be run
in a separate conduit from input cables.

3. Aluminum and copper clad aluminum cables
are not recommended.

4. All wiring is to be in accordance with national
and local electrical codes

3.5"
(89mm)

PSP11010
Rev. 1

No Customer

Connections

SOURCE BUSBAR

DETAIL A

A

B

C

A

B

C

Source 2 Busbar
Approx. 7.5 x 3.2
(191 x 81mm)
1/2"-13 PEM Nut
Typ. 4 Places

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 34

Figure 25 Electrical field connections, 250A Liebert STS2/PDU input with CB3 & CB3A

See Source
Busbar
Detail A

CB1

CB4

CB3

CB3A

See Ground
Busbar Detail B

CB6

Source 1

Source 2

FRONT

Doors and Accent Panels

Not Shown

8" (203mm)

1.77"

(45mm)

CB7

CB2

CB5

No Customer

Connections

1.75"

(44mm)

Typical

A

B

C

SOURCE BUSBAR

DETAIL A

A

B

C

A

B

C

Source 1 Busbar
Approx. 7.5 x 3.2
(191 x 81mm)
1/2"-13 PEM Nut
Typ. 4 Places

No Customer

Connections

Source 2 Busbar
Approx. 7.5 x 3.2
(191 x 81mm)
1/2"-13 PEM Nut
Typ. 4 Places

.51" DIA.

(13mm)

Typ. 4 Places

1.75" (44mm)

GROUND BUSBAR

DETAIL B

3.5"
(89mm)

1. Phase, neutral and ground busbars are 1/4" thick.

2. Control wiring and power wiring must be run
in separate conduit. Output cables should be run
in a separate conduit from input cables.

3. Aluminum and copper clad aluminum cables
are not recommended.

4. All wiring is to be in accordance with national
and local electrical codes

PSP11011
Rev. 1

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 35

Figure 26 Electrical field connections, 400-600A Liebert STS2/PDU input with CB3

Ground

CB6 CB1 CB2

CB7 CB5CB4

CB3

FRONT

Doors and Accent Panels

Not Shown

.56" DIA.

(14.3mm)

.75"

(19.1mm)

.56" DIA.

(14.3mm)

Typ. 6 Places

.41" DIA.

(10.3mm)

Typ. 8 Places

2"

(50.8mm)

1" (25.4mm)

1. Phase, neutral and ground busbars are 1/4" thick.

2. Control wiring and power wiring must be run
in separate conduit. Output cables should be run
in a separate conduit from input cables.

3. Aluminum and copper clad aluminum cables
are not recommended.

4. All wiring is to be in accordance with national
and local electrical codes

INPUT BUSBAR DETAIL, TYPICAL

GROUND BUSBAR DETAIL

PSP11012
Rev. 1

1.75"

(44.5mm)

1.75"

(44.5mm)

1.75" (44.5mm)

1.75" (44.5mm)

0.63"

(15.9mm)

1.13"

(28.6mm)

3" (76.2mm)

1.13" (28.6mm)

2.88"

(73.2mm)

12.75" (323.9mm)

1.77"

(45mm)

9" (228.6mm)

Source 1 Input Ø B

Source 1 Input Ø A

Source 1 Input Ø C

Source 2 Input Ø B

Source 2 Input Ø A

Source 2 Input Ø C

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 36

Figure 27 Electrical field connections, 400-600A Liebert STS2/PDU input with CB3 and CB3A

CB3A

Ground

CB6 CB1 CB2

CB7 CB5CB4

CB3

FRONT

Doors and Accent Panels

Not Shown

.56" DIA.

(14.3mm)

.75"

(19.1mm)

.56" DIA.

(14.3mm)

Typ. 6 Places

.41" DIA.

(10.3mm)

Typ. 8 Places

2"
(50.8mm)

1" (25.4mm)

1. Phase, neutral and ground busbars are 1/4" thick.

2. Control wiring and power wiring must be run
in separate conduit. Output cables should be run
in a separate conduit from input cables.

3. Aluminum and copper clad aluminum cables
are not recommended.

4. All wiring is to be in accordance with national
and local electrical codes

INPUT BUSBAR DETAIL, TYPICAL

GROUND BUSBAR DETAIL

PSP11013
Rev. 1

1.75" (44.5mm)

1.75" (44.5mm)

1.75" (44.5mm)

0.63"

(15.9mm)

1.13"

(28.6mm)

3"

(76.2mm)

1.13" (28.6mm)

2.88"

(73.2mm)

12.75" (323.9mm)

9" (228.6mm)

Source 1 Input Ø B

Source 1 Input Ø A

Source 1 Input Ø C

Source 2 Input Ø B

Source 2 Input Ø A

Source 2 Input Ø C

1.75" (44.5mm)
Typical

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 37

Figure 28 Electrical field connections, 800A Liebert STS2/PDU input with CB3

Source #1

SECTION A - A

ABC

ABC

ABC

Source #2
See Input
Busbar Detail

Ground busbar
(not shown) is
located under
Source #1
busbars.

(15.9mm)

1.75" (44.5mm)

1.13"

(28.6mm)

0.63"

Typ. 6 Places

2.88"

(73.2mm)

GROUND BUSBAR DETAIL

Breaker
Section

CB4

CB3

CB1 CB2

.56" DIA.

(14.3mm)

1.75" (44.5mm)

12.75" (323.9mm)

CB5

1.75" (44.5mm)
Typical

Typical

.41" DIA.

(10.3mm)

Typ. 8 Places

3"

(76.2mm)

1.13"

(28.6mm)

A A

SEE SECTION A - A

Ground Busbar
See busbar detail.

LEFT SIDE

Accent Panels Not Shown

1. Phase, neutral and ground busbars are 1/4" thick.

2. Control wiring and power wiring must be run
in separate conduit. Output cables should be run
in a separate conduit from input cables.

3. Aluminum and copper clad aluminum cables
are not recommended.

4. All wiring is to be in accordance with national
and local electrical codes

CB6

FRONT

Doors and Accent Panels

Not Shown

1" (25.4mm)

1.75" (44.5mm)

.75"

(19.1mm)

INPUT BUSBAR DETAIL, TYPICAL

7.5" (190.5mm)

CB7

.46" DIA.

(11.7mm)

2"
(50.8mm)

PSP11014
Rev. 1

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 38

Figure 29 Electrical field connections, 800A Liebert STS2/PDU input with CB3 and CB3A

A A

SECTION A - A

SEE SECTION A - A

Ground busbar
(not shown) is
located under
Source #1
busbars.

Ground Busbar
See busbar detail.

Breaker
Section

CB6

CB1

CB2

CB7

CB5

CB4

CB3

CB3A

FRONT

Doors and Accent Panels

Not Shown

LEFT SIDE

Accent Panels Not Shown

.46" DIA.

(11.7mm)

.75"

(19.1mm)

.56" DIA.

(14.3mm)

Typ. 6 Places

.41" DIA.

(10.3mm)

Typ. 8 Places

2"
(50.8mm)

1" (25.4mm)

1. Phase, neutral and ground busbars are 1/4" thick.

2. Control wiring and power wiring must be run
in separate conduit. Output cables should be run
in a separate conduit from input cables.

3. Aluminum and copper clad aluminum cables
are not recommended.

4. All wiring is to be in accordance with national
and local electrical codes

INPUT BUSBAR DETAIL, TYPICAL

GROUND BUSBAR DETAIL

PSP11015
Rev. 1

1.75" (44.5mm)

1.75" (44.5mm)

1.75" (44.5mm)
Typical

0.63"

(15.9mm)

1.13"

(28.6mm)

3"

(76.2mm)

1.13"

(28.6mm)

2.88"

(73.2mm)

12.75" (323.9mm)

7.5" (190.5mm)

Source #1

Source #2
See Input
Busbar Detail

ABC ABC

1.75" (44.5mm)
Typical

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 39

Figure 30 Electrical field connections, 250A Liebert STS2/PDU output with inline panelboards

PSP11003
Rev. 0

FRONT

Side Panel Not Shown

LEFT SIDE

Doors and Accent Panels Not Shown

NCBA

TB5

NCB G

TB4

Subfeed Breaker

CB10 Output

Connection

Subfeed Breaker

CB11 Output

Connection

A

Subfeed Breaker
(CB10) (Optional)

Panelboard Main Breaker

CB8

and (CB9)

GROUND
CONNECTIONS

NEUTRAL CONNECTIONS

Distribution Cables
Neutral(s) connected
to distribution panelboard
neutral busbar

Distribution Cable
Ground(s) connected
to distribution panelboard
ground busbar.

42 Pole
Distribution
Panelboards

Subfeed Breaker
CB11, Optional

G

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 40

Figure 31 Electrical field connections, 400-800A Liebert STS2/PDU output with inline panelboards

PSP11000
Rev. 2

Panelboard Main

Breaker

CB11

and CB10

FRONT

Side Panel Not Shown

LEFT SIDE

Doors and Accent Panels Not Shown

NCBA

TB5

NCBG

TB4

Subfeed Breaker

CB12 Output

Connection

Subfeed Breaker

CB13 Output

Connection

A

Subfeed Breaker
CB13, Optional

Panelboard
Main Breaker

CB8

and CB9

Ground
Connections

Neutral Connections
Distribution Cables
Neutral(s) connected
to distribution
panelboard
neutral busbar

Distribution Cable
Ground(s) connected
to distribution
panelboard
ground busbar.

42 Pole
Distribution
Panelboards

Subfeed Breaker
CB12, Optional

G

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 41

PSP11001
Rev. 2

I - Line Panelboard

Output Neutral
Busbar See Detail A

Output Ground
Busbar See Detail B

LEFT SIDE

Panels Not Shown

28.4" (721mm)

27.7" (703.6mm)

4"

(102 mm)

3.28"
(83.3mm)

3.28"
(83.3mm)

3.28"
(83.3mm)

2.06" (52.3mm) Typ.

DETAIL B

Output Ground

Busbar Approx. 1/4" Thick

DETAIL A

Output Neutral

Busbar Approx. 1/2" Thick

.56" DIA.
(14.2mm)
Typ. 20 Places

4"

(102 mm)

.56" DIA.
(14.2mm)
Typ. 20 Places

2.06" TYP

FRONT

Doors and Accent Panels

Not Shown

Output Breakers

Typical

NOTES

1. 250 - 600A units can accommodate
10 breakers rated 100 - 250A.

2. 800A units can accommodate:
10 breakers rated 100 - 250A or
6 breakers rated 300-400A

1.75"
(44mm)

1.75"
(44mm)

3.1"

(78.7mm)

3.36"

(85.3mm)

Figure 32 Electrical field connections, Liebert STS2/PDU output with I-Line panelboard

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 42

Figure 33 Electrical field connections, 400-600A Liebert STS2/PDU with right side output breaker

PSP11004
Rev. 1

RIGHT SIDE

Doors and Accent Panels Not Shown

Output
Breaker
CB8

Phase A

Phase B

Phase C

Neutral

Ground

BUSBAR DETAIL

1. Phase and ground busbars are 1/4" thick.

2. Neutral busbar is 1/2" thick.

10.3" (262mm)

1"

(25.4mm)

1.75" (44.5mm)

2" (51mm)

4"

(102mm)

.56" DIA.

(14.2mm)

Typ. 4 Places

0.75"

(19mm)

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 43

Figure 34 Electrical field connections, 400-600A Liebert STS2/PDU with left side output breaker

Output
Breaker
CB8

Phase A

Phase B

Phase C

Neutral

Ground

10.3" (262mm)

1.75" (44.5mm)

.56" DIA.

(14.2mm)

Typ. 4 Places

BUSBAR DETAIL

1. Phase and ground busbars are 1/4" thick.

2. Neutral busbar is 1/2" thick.

1"

(25.4mm)

2" (51mm)

0.75"

(19mm)

4"

(102mm)

LEFT SIDE

Doors and Accent Panels Not Shown

PSP11005
Rev. 1

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 44

Figure 35 Electrical field connections, 800A Liebert STS2/PDU with right side output breaker

PSP11006
Rev. 0

RIGHT SIDE

Doors and Accent Panels Removed

Output
Breaker
CB8

Phase A

Phase B

Phase C

Neutral

Ground

Notes

1. Phase and ground busbars are 1/4" thick.

2. Neutral busbar is 1/2" thick.

BUSBAR DETAIL

10.3" (262mm)

1"

(25.4mm)

2" (51mm)

1.75" (44.5mm)

0.75" (19mm)

4"

(102mm)

0.56" (14.2mm)

Typical, 4 Places

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 45

Figure 36 Electrical field connections, 8600A Liebert STS2/PDU with left side output breaker

PSP11007
Rev. 0

LEFT SIDE

Doors and Accent Panels Removed

Output
Breaker
CB8

Phase A

Phase B

Phase C

Neutral

Ground

Notes

1. Phase and ground busbars are 1/4" thick.

2. Neutral busbar is 1/2" thick.

BUSBAR DETAIL

10.3" (262mm)
1"

(25.4mm)

2" (51mm)

1.75" (44.5mm)

0.75" (19mm)

4"

(102mm)

0.56" (14.2mm)

Typical, 4 Places

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 46

Figure 37 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring

PSP11018
Rev. 0

A A

B

B

Neutral Busbar
See Neutral
Busbar Detail

Ground Busbar
See Ground
Busbar Detail

.44 Dia.
(11.2mm)
Typ. 6 Places

See Section B-B
Drawing PSP11019

See Section A-A
Drawing PSP11019

See Section C-C
Drawing PSP11019

C

C

Breaker
Section

STS
Section

Front

LEFT SIDE

Breaker Section

Accent Panels Removed

RIGHT SIDE

STS Section

Accent Panels Removed

Notes

1. Phase and ground busbars are 1/4" thick.

2. Neutral busbar is 1/2" thick.

GROUND BUSBAR DETAIL

NEUTRAL BUSBAR DETAIL

0.56" (14.2mm)

Typical, 6 Places

0.41" (10.3mm)

Typical, 8 Places

1.5"

(38.1mm)

1.5" (38.1mm)

3"

(76.2mm)

3"

(76.2mm)

1.13"

(28.6mm)

1.13" (28.6mm)

2.88"

(73.2mm)

6"

(152.4mm)

12.75" (323.9mm)

1.75"

(44.5mm)

1.75" (44.5mm)

1.75" (44.5mm)

1.75" (44.5mm)

1.5"

(38.1mm)

0.63"

(16mm)

0.63"

(16mm)

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 47

Figure 38 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, breaker section

PSP11019
Rev. 0

SECTION A - A

Breaker Section

SECTION B - B

BREAKER SECTION

SECTION C - C

STS SECTION

TB1
See Enlarged
Detail Below

TB1-1 TB1-2 TB1-3

TB2 and TB3
See Enlarged
Detail Below

TB2-1

TB2-2

TB2-3

TB3-1

TB3-2

TB3-3

H1 H2 H3 X1 X2 X3 X0 Shield Wire

0.50" DIA.
(12.7mm)
Typical,
3 Places

0.50" DIA.
(12.7mm)
Typical,
6 Places

.42 DIA.
(10.7mm)
Typical,

6 Places

.56 DIA.
(14.2mm)
Typical,
16 Places

.38 DIA.
(9.6mm)

Ground Busbar
See Ground
Busbar Details in
Drawing PSP11018

TB2

TB3

TB1

Neutral Busbar
See Drawing
PSP11018

T2

T1

NOTES

1. Interconnection wiring from T1 to TB1, 2, 3 and neutral busbars are
attached to T1 and shipped in the STS section.

2. Refer to drawing PSP11018 for section location details and for
neutral and ground busbar details.

Table 8 Interconnection wiring, from STS

section to breaker section

From T1 To Wire Number

H1 TB1-1 7AA and 7BB

H2 TB1-2 8AA and 8BB

H3 TB1-3 9AA and 9BB

X1 TB2-1 13AA and 13BB

X1 TB2-2 13CC and 13DD

X2 TB2-3 14AA and 14BB

X2 TB3-1 14CC and 14DD

X3 TB3-2 15AA and 15BB

X3 TB3-3 15CC and 15DD

X0 Neutral Busbar

Shield Wire Ground Busbar

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 48

PSP11020
Rev. 0

FRONT

STS Section

Accent Panels Not Shown

W21A,B,C, & D to
Source 1 Phase A

W22A,B,C, & D to
Source 1 Phase B

W23A,B,C, & D to
Source 1 Phase C

Unit Front

W27A,B,C & D to
Output Phase A

W24A,B,C, & D to
Source 2 Phase A

W25,A,B,C, & D to
Source 2 Phase B

W29A,B,C, & D to
Output Phase C

W26A,B,C, & D to
Source 2 Phase C

W28A,B,C, & D to
Output Phase B

RIGHT SIDE

STS Section

Accent Panels Not Shown

Notes

1. Take labeled wires from breaker section (cabinet
not shown) through CTs and through-holes as shown
in Section D - D of STS cabinet. Attach wires to
busbars in STS cabinet. See Section E - E for details.

2. See drawing PSP11018 for breaker section of cabinet.

D

Section
D - D

Section
E - E

D

E

E

CTs and
Through-Holes
Typical
See Section D-D

SECTION D - D

Move wire groups from breaker cabinet
through above section of STS2 cabinet.

SECTION E - E

With fuse bracket removed

attach wires to the

corresponding busbars

SEE

SECTION

E - E

Source 2 Phase A
W24A,B,C & D

Output Phase A
W27A,B,C & D

Output Phase B
W28A,B,C & D

Source 2 Phase B
W25,A,B,C & D

Output Phase C
W29A,B,C & D

Source 2 Phase C
W26A,B,C, & D

Source 1 Phase A
W21A,B,C, & D

Source 1 Phase B
W22A,B,C, & D

Source 1 Phase C
W23A,B,C & D

FRONT

Figure 39 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, STS section

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 49

Figure 40 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, left side distribution cabinet

PSP11021
Rev. 0

NOTES

1. The neutral is factory-wired.

2. Interconnection wiring from breaker busbars A, B and C to
Distribution Section are attached to breaker busbars and shipped in
the breaker section.

Distribution Cabinet

on Left

FRONT

Side Panel Not Shown

A

A

SECTION A - A

See Details Below

See Section

A - A

BUSBAR DETAILS

A, B and C

.44" Dia.

(11.2mm) Typ.

7 Places

.52" Dia. (13.2mm)

Typ. 4 Places

2.09" (53mm)
Spacing Typ.

TOP REAR OF BREAKER SECTION

Panel Not Shown

Busbar B

Busbar C

Busbar A

A

B

C

CB3

CB3A

CB2

CB5

CB1

CB4

36A,B,C,D

37A,B,C,D

38A,B,C,D

1"

(25.4mm)

2" (50.8mm)

25.9" (657.9mm)

2.5"

(63.5mm)

Table 9 Interconnection wiring from Breaker Section to

Distribution Section

From Breaker

Busbar

To Distribution

Busbar

Wire

Number

A A 36A, B, C, D

B B 37A, B, C, D

C C 38A, B, C, D

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Figure 41 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, left side one-line

Busbar A

Busbar B

Busbar C

See
Drawing
PSP11019
For Details

Distribution
Section

H1 H2 H3

STS

Area

See Drawing PSP11020

Section E - E

X3 X0X1 X2

Transformer

T1

STS
Section

CT

CB3

W27
W28
W29

W21

CB1

W22
W23

See Drawing Psp11020

Section D - D

TB1

TB2

TB3

Transformer

T2

Breaker
Section

CB2

Busbar A

Busbar B

Busbar C

See Drawing
PSP11021
For Details

W24
W25
W26

Ground
Busbar

FRONT

Accent Panels Not Shown

1. Interconnection wiring from T1 to TB1, 2, 3 and neutral busbars are attached to T1 and shipped in the STS section.
See Drawing PSP11019 for details.

2. Interconnection wiring from CB1, CB2 and CB3 to STS section are attached to CB1, CB2, & CB3 and shipped
in the breaker section. See Drawing PSP11020 for details.

3. Interconnection wiring from breaker. Busbars a, b and c to distribution section are attached to brkr. Busbars and
shipped in the breaker section. See Drawing PSP11021 for details.

Neutral
Busbar

PSP11024
Rev. 0

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Figure 42 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, left side one-line with CB3A

PSP11025
Rev. 0

FRONT

Accent Panels Not Shown

CB2

Breaker
Section

CB1

Distribution
Section

TB3

TB2

TB1

Neutral Busbar

Busbar A

Busbar B

Busbar C

Busbar A

Busbar B

Busbar C

CT

Ground
Busbar

See
Drawing
PSP11019
For Details

STS
Section

H1 H2 H3

X3 X0X1 X2

Transformer Transformer

T1

T2

W21
W22

W23

W24
W25
W26

See
Drawing
PSP11021
For Details

W27
W28
W29

CB3A

NOTES

1. Interconnection wiring from T1 to TB1, 2, 3 and neutral busbars are attached to T1 and shipped in the STS section.
See drawing PSP11019 for details.

2. Interconnection wiring froM CB1, CB2 and CB3A to STS section are attached to CB1, CB2 and CB3A and shipped
in the breaker section. See drawing PSP11020 for details.

3. Interconnection wiring from breaker busbars A, B and C to distribution section are attached to breaker busbars and
shipped in the breaker section. See dwg psp11021 for details

See Drawing PSP11020
Section E - E

See Drawing PSP11020
Section D - D

STS

AREA

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Figure 43 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, right side one-line

See
Drawing
PSP11019
For Details

STS
Area

See Drawing PSP11020

Section E - E

H1 H2 H3

Transformer

T1

X3 X0X1 X2

STS
Section

CT

Breaker
Section

CB3

W27
W28
W29

W21

CB1

W22
W23

See Drawing PSP11020

Section D - D

TB1

TB2

TB3

Transformer

T2

CB2

Distribution
Section

W24
W25
W26

FRONT

Accent Panels Not Shown

NOTES

1. Interconnection wiring from T1 to TB1, 2, 3 and neutral busbars are attached to T1 and shipped in the STSsection.
See drawing PSP11019 for details.

2. Interconnection wiring from CB1, CB2 and CB3 to STS section are attached to CB1, CB2 and CB3 and shipped
in the breaker section. See drawing PSP11020 for details.

Neutral
Busbar

Ground

Busbar

PS
Rev. 0P11026

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Figure 44 Electrical field connections, 800A Liebert STS2/PDU interconnect wiring, right side one-line with CB3A

See
Drawing
PSP11019
For Details

STS

Area

See Drawing PSP11020

Section E - E

H1 H2 H3

Transformer

T1

X3 X0X1 X2

STS
Section

CT

Breaker
Section

W21

CB1

W22
W23

See Drawing PSP11020

Section D - D

TB1

TB2

TB3

W27

CB3A

W28
W29

Transformer

T2

CB2

Distribution
Section

W24

W25

W26

FRONT

NOTES

1. Interconnection wiring from T1 to TB1, 2, 3 and neutral busbars are attached to T1 and shipped in the STS section.
See drawing psp11019 for details.

2. Interconnection wiring from CB1, CB2 and CB3A to STS section are attached to CB1, CB2 and CB3A and shipped
in the breaker section. See drawing PSP11020 for details.

Accent Panels Removed

Neutral
Busbar

PSP11027
Rev. 0

Ground
Busbar

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Figure 45 Control wiring, 800A Liebert STS2/PDU, left side distribution

PSP13801
Rev. 0

CONNECT THE FOLLOWING

CN15 Cap to CN15 Plug
CN25 Cap to CN25 Plug
CN31 Cap to CN31 Plug
CN33 Cap to CN33 Plug
CN34 Cap to CN34 Plug
CN35 Cap to CN35 Plug

FRONT

Accent Panels Not Shown

STS
Section

STS

AREA

Distribution
Section

Breaker
Section

Breaker

Area

Fan Assembly

CN25
(Plug)

CN33
(Plug)

CN25
(Cap)

CN33
(Cap)

CN15
(Cap)

Display
HMI

CN15
(Plug)

CN34
(Plug)

CN34
(Cap)

CN31
(Plug)

CN35
(Plug)

CN35
(Cap)

CN31
(Cap)

P66

VI

Board

P999

Monitor
Board

P17

P4

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Figure 46 Control wiring, 800A Liebert STS2/PDU, right side distribution

PSP13802
Rev. 0

CONNECT THE FOLLOWING:

CN15 Cap to CN15 Plug
CN25 Cap to CN25 Plug
CN31 Cap to CN31 Plug
CN34 Cap to CN34 Plug
CN35 Cap to CN35 Plug

P999

FRONT

Accent Panels Removed

CN34
(Cap)

CN34
(Plug)

CN31
(Cap)

CN15
(Cap)

CN25
(Cap)

CN25
(Plug)

CN15
(Plug)

CN31
(Plug)

CN35
(Cap)

STS
Section

CN35
(Plug)

P17

Breaker

Area

Breaker
Section

Distribution
Section

Display
HMI

P66

STS

AREA

Fan Assembly

Monitor

Board

VI

Board

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Figure 47 Control connection location, 250A Liebert STS2/PDU

PSP13200
Rev. 1

NOTES

1. Typical options are shown.

2. Maximum of two programmable
relay boards can be used.

CONTROL WIRING

FRONT

Front Door Not Shown

Comms Board for
Liebert SiteScan,
External and Internal
Modem Interface (Option)

Input Contact Isolator Board
(Option) or Programmable Relay
Board (Option) See Note 2

See Option
Location Detail

OPTION LOCATION DETAIL

Network Interface
Card (NIC) (Option)

Remote Source
Select (Option)

Programmable Relay
Board (Option) See Note 2

Programmable Relay
Board (Option) See Note 2

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Figure 48 Control connection location, 400-800A Liebert STS2/PDU

PSP13800
Rev. 1

NOTES

1. Typical options are shown.

2. Maximum of two programmable
relay boards can be used.

CONTROL WIRING

FRONT

Front Door Not Shown

Comms Board for
Liebert SiteScan,
External and Internal
Modem Interface (Option)

Input Contact Isolator Board
(Option) or Programmable Relay
Board (Option) See Note 2

See Option
Location Detail

OPTION LOCATION DETAIL

Network Interface
Card (NIC) (Option)

Remote Source
Select (Option)

Programmable Relay
Board (Option) See Note 2

Programmable Relay
Board (Option) See Note 2

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Figure 49 Control location drawing conduit box, top entry, 400-600A Liebert STS2/PDU

PSP13401
Rev. 1

UNIT WITH CONDUIT

BOX INSTALLED

Control Conduit Box

TOP VIEW

DETAIL A

Remove side cover to install conduit

and cables. Then replace side cover.

Control Conduit Box
See Detail A and Notes.

NOTES

1. The control conduit box is mounted
upside down and inside of top of the unit
for shipping.

2. Remove the box and side cover.

3. Drill top of box for conduits.

4. Replace the box as shown in the
installed view.

5. Install conduit and land cables.

6. Replace side cover.

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Figure 50 Control wiring for the programmable relay board option

J71

J72

J74

PROGRAMMABLE RELAY BOARD

PIN NO.CHANNEL

1 - 3

CH1

J71

CH2

CH3

J72

CH4

CH5

CH6

J73

J74

CH7

CH8

NOTE: Pin 16 not used on J71, J72 and J73

A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B

4 - 6
7 - 9

10 - 12

13 - 15

1 - 3
4 - 6
7 - 9

10 - 12

13 - 15

1 - 3
4 - 6
7 - 9

10 - 12

13 - 15

1 - 3

C

1
4

7
10
13

1

4

7
10
13

1

4

7
10
13

1

NC

2
5

8
11
14

2

5

8
11
14

2

5

8
11
14

2

NO

3
6

9
12
15

3

6

9
12
15

3

6

9
12
15

3

J73

NOTES

1. Customer control wiring connection points are
Terminal Blocks 1 through 15.

2. Programmable relay board option includes eight
signal channels with two Form-C dry contacts per
channel. See table.
(C=Common, NC=Normally Closed, NO=Normally Open)

3. Refer to other portions of this document for configuring
the programmable relay board option.

4. All control wiring (by others) must be run
separate from power wiring. Control wiring runs
should not be combined in the same conduit.

5. Refer to static transfer switch control connection
diagram for location of program relay board option.

6. Contact ratings: 1amp @ 30VDC, 200mA @125VAC.

7. Maximum cable length 500 ft. (152m) with
#16AWG flexible stranded cable.

8. All wiring must be in accordance with national
and local electrical codes.

PS213001
Rev. 2

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Figure 51 Control wiring for the input contact isolator board option

1162345 7896151413121110

J51

“NO CUSTOMER CONNECTION”

INPUT CONTACT ISOLATOR BOARD

02-810012-XX

PS213002
Rev. 02

NOTES:

1. Customer control wiring connection points are Terminals 1 through 16
(see Table J51).

2. Customer-provided, normally open, dry contacts for user alarm messages.

3. Refer to installation, operation AND maintenance manual for configuring the input contact
isolator board option.

4. All control wiring (by others) must be run separate from power wiring. Control wiring runs
should not be combined in the same conduit.

5. Refer to static transfer switch control connection diagram for location of input contact isolator
board option.

6. Signal voltage: 100mA @ 12VDC.

7. Maximum cable length 500 ft. (152 meters) with #16 AWG flexible, stranded cable.

8. All wiring must be in accordance with national and local electrical codes.

Table J51

Input

Contact Pin No.

1

1

2

2

3

4

3

5

6

4

7

8

5

9

10

6

11

12

7

13

14

8

15

16

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Figure 52 Control wiring for Comms board

J81

TB51 TB55 TB56

No Customer
Connection

Notes

1. Maximum cable length 1000 ft. (300m)
with twisted pair cable #22 AWG 300V minimum.

2. All control wiring (by others) must be run
separate from power wiring. Control wiring
runs should not be combined in the same conduit.

3. Refer to control connection location diagram
of static transfer switch for location of Comms Board.

4. All wiring must be in accordance with national
and local electrical codes.

Liebert Sitescan
See Detail A

COMMS BOARD

02-810015-XX

J1A

No Customer
Connection

PS213003
Rev. 4

Customer-Supplied

Interconnecting

Cable to Liebert SiteScan

See
Note 1

1

2

3

TB55

Detail A

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Figure 53 Control wiring for the Liebert IntelliSlot™ Web/485 Card With Adapter option

Customer-Supplied

Interconnecting

Cable to Modbus 485

See Note 2

-

+

No Customer
Connection

TB1

RS-232 (DB9
Connector)
for Setup only;
uses standard
computer serial
port cable

No Customer
Connection

TB2

DB9

Notes

1. Wire size and type: 10/100 Base-T Ethernet cable with RJ-45 plug connector.
The length is limited by internet standards.

2. Maximum cable length 1000 ft. (300m) with twisted pair cable #22 AWG minimum.
Signal voltage 5VDC, current 10mA.

3. Refer to other portions of this document for configuring the Liebert IntelliSlot

4. All control wiring (by others) must be run separately from power wiring.
Control wiring runs should not be combined in the same conduit.

5. Refer to control connection location diagram of static transfer switch for location of Liebert
IntelliSlot Web/485 card option.

6. All wiring must be in accordance with national and local electrical codes.

J3

TB3

Ethernet Network
RJ-45 Connector

See Notes 1 and 2.

™

Web/485 card.

PS213008
Rev. 3

Customer-Supplied

Interconnecting Cable:

SNMP

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Figure 54 Control wiring for the RS-232 Port

See Detail A

Liquid

Crystal

Display

6789

1234

Txd Rxd

DB9 Connector

Detail A

Notes

1. RS-232 communication through DB9
connector.

2. Connector accessible with front door
opened. connector must be removed before
closing door.

5

Gnd

FRONT VIEW

Upper Half of Unit

With Door Open

PS213006
Rev. 1

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Figure 55 Control wiring for remote source selection option

Remote Source Selection

Source 1
Preferred

Source 2
Preferred

246

See Note 1

Notes

1. Customer provided normally open dry contacts.
rating 10mA at 30VDC.

2. Maximum cable length 500 ft. (152m) with
#16AWG 300V minimum, flexible stranded cable.

3. All control wiring (by others) must be run
separately from power wiring. Control wiring runs
should not be combined in the same conduit.

4. Refer to static transfer switch control connection
diagram for location of remote source selection opt.

5. All wiring must be in accordance with national
and local electrical codes.

S1 GNDS2 GND

TB50

135

PS213007
Rev. 2

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Figure 56 Color LCD touchscreen

PSP11900

Rev. 1

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 66

Table 10 Input circuit breaker schedule, 250-800A

Liebert

STS2/PDU

Rating

250A

400A

600A

800A

Liebert

STS2/PDU

Input Volts

208V

480V NFNN 150A 380-480V 35K

600V NFNN 125A 600V 18K

480V

600V NJHN 200A 600V 25K

480V

600V NJHN 300A 600V 25K

480V

600V NJHN 400A 600V 25K

Circuit Breakers

(See One-Line

Diagrams) Vendor Type Ampacity Voltage

NJHN 400A 208-240V 100K

CB6 & CB7

CB6 & CB7

CB6 & CB7

CB6 & CB7

MERLIN

GERIN

MERLIN

GERIN

MERLIN

GERIN

MERLIN

GERIN

NJHN 250A 380-480V 65K

NJHN 400A 380-480V 65K

NJHN 500A 380-480V 65K

Table 11 Output circuit breaker schedule, 250-800A

Liebert

STS2/PDU

Rating

250A 208V CB8

400A 208V CB8

600A 208V CB8 Square D PGD 600A 208-240V 65K

800A 208V CB8 Square D PGD 800A 208-240V 65K

Liebert

STS2/PDU

Input Volts

Circuit Breakers

(See One-Line

Diagrams) Vendor Type Ampacity Voltage

MERLIN

GERIN

MERLIN

GERIN

NJHN 250A 208-240V 100K

NJHN 400A 208-240V 100K

Interrupting

Rating (Amps)

Interrupting

Rating (Amps)

Table 12 Non-automatic breaker schedule, 250-800A

Liebert STS2/PDU

Rating

250A

400A

600A

800A

Circuit Breakers

(See One-Line

Diagrams) Vendor Type Ampacity Voltage

CB1, CB2, CB3

CB3A, CB4, CB5

CB1, CB2, CB3

CB3A, CB4, CB5

CB1, CB2, CB3

CB3A, CB4, CB5

CB1, CB2, CB3

CB3A, CB4, CB5

Square D JLN 250A

MERLIN

GERIN

MERLIN

GERIN

Square D PJD 1000A 208-240V 100K

Withstand

Current

208-240V 125K

380-480V 100K

NSJ 400A

NSJ 600A 208-240V 100K

208-240V 100K

380-480V 100K

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 67

8.0 INTRODUCTION TO LIEBERT STS2/PDU OPERATION

8.1 System Description

A Liebert STS2/PDU provides an automatic, seamless transfer between input power sources to an output load.
The Liebert STS2/PDU monitors the input sources, to ensure each source is operating within set parameters, as
well as ensure that each source is within acceptable tolerances for a transfer between sources to be completed.

The Liebert STS2/PDU contains two static transfer switches in one enclosure to allow the unit to transfer its load
between the two input sources without disruption to the output for longer than 1/4 of a cycle.

If a problem is detected with a primary (Preferred) input source and defined trigger points are reached, the
Liebert STS2/PDU automatically switches the input to the other (Alternate) input source. The Liebert STS2/PDU
continues to monitor both sources and can automatically transfer the load back to the preferred source, if so
configured, when that source returns to acceptable operating parameters.

The system control logic automatically monitors the input sources and power output to ensure that they are
operating within acceptable tolerances. The system logic manages the transfer between sources.

The Liebert STS2/PDU front panel contains a Color Graphical Display on an LCD touchscreen. The Color
Graphical Display provides a menu-driven operator interface and a display of system information, status
information, a one-line diagram (Mimic) of the Liebert STS2/PDU, active alarms and alarm history information.

The menu selections provide control of the preferred source, manual transfer initiation. Buttons provide for
audible alarm silence and reset.

Through the touchscreen, specific voltage, current and environmental parameters can be configured to trigger
events that can sound an alarm, write to a history log and either transfer sources or inhibit a transfer.

Preferred input source selection, alarm reset and alarm silencing are done through buttons on the touchscreen.

Communication options provide external communication with the Liebert STS2/PDU through a modem, a
network card, a programmable relay board, a contact isolator or an RS-422 port to Liebert’s SiteScan.

8.1.1 Redundancy

Redundancy within the Liebert STS2/PDU prevents one component from being a single point of failure, should a
problem occur. Redundant circuits and components are used to eliminate single points of failure.

Since the Liebert STS2/PDU has two input sources, no single component failure can cause a loss of power to the
load. Redundant power supplies are provided which feed a DC dual-bus used throughout the unit to prevent any
single-point power supply failure modes.

Three separate redundant control logic modules are built into the system. Each contains the logic necessary to
run the Liebert STS2/PDU and control all transfers.

Redundant fans are provided if a primary fan fails. The redundant fans turn on to prevent overheating inside of
the unit.

Should the front panel interface fail, the control logic continues to operate and the unit would transfer should a
problem be detected on the preferred source. Information on the monitoring parameters would be available
through the remote communication options, if available, or the DB9 (RS-232) connector located next to the LCD
behind the front door. See Figure 54 for details.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 68

8.1.2 Reliability and Agency Requirements

The Liebert STS2/PDU is designed for high reliability and high availability with a critical bus Mean Time Between
Failure (MTBF) exceeding 1,000,000 hours.

The Liebert STS2/PDU and all its options are designed, tested and certified, where applicable, to meet agency
requirements as follows:

• UL 891: Standard for Switchboard, for UL and ULc listing

• UL 1008: Standard for Automatic Transfer Switches

• UL 67: Standard for Panelboard

• UL 1561: Standard for Dry Transformers

• UL 1459: Telephone equipment (Modem)

•NEC

• FCC Part 15 EMI emission limits for Class A computing devices.

•U.S. Department of Energy 2016

The Liebert STS2/PDU uses conservatively rated components, minimizing the need to go to maintenance
bypass. All normal maintenance and repair work can be done through the front panel of the unit. This access
makes repairs and maintenance easier.

Gating and control logic are partitioned so that failure of one source’s gating or sensing logic does not prevent
the switch from transferring to the other source.

All control and logic components are mounted separate from the power components. The Liebert STS2/PDU is
designed to minimize the exposure of hazardous voltages to allow safe servicing of the unit while the load is
energized.

All electrical components requiring normal maintenance are replaceable without de-energizing the load, as long
as one source is available. Solid-state switching devices are packaged to allow safe repair of those devices
without having to de-energize the load. All non-automatic switches or circuit breakers are the plug-in or draw­out type to allow replacement without de-energizing the load. All other components, including transformers,
power cables and connections, circuit breaker bases, etc., are replaceable from the front, rear or top of the unit—
however, this requires all power to be removed from the unit for safety. All solid-state power switching devices
are rated to prevent hazardous device failure in power systems with available fault currents up to the defined
limits, as listed in 14.1.6 - Electrical Requirements.

8.1.3 Factory Backup and Service Assistance

Because improper installation can cause a system to fail, a Vertiv Services or a factory-trained service technician
should thoroughly inspect the unit to ensure it is properly installed and its operating parameters are properly
configured.

Once the Liebert STS2/PDU is properly installed, you, as the on-site operator, can easily monitor the unit’s
operation utilizing the touchscreen.

In the United States, if you need assistance or have questions, call 1-800-LIEBERT (1-800-543-2378).

Outside the 48 contiguous United States, contact Vertiv Services, if available in your area.

For international areas not covered by Vertiv Services, the Vertiv-authorized distributor can provide technical
support.

8.2 Modes of Operation

8.2.1 Normal (Preferred Source)

Under normal operating conditions, the Liebert STS2/PDU routes power from the preferred input source to the
output load. The unit monitors the voltage, current and phase of each source to ensure that both are operating
within set tolerances and that the alternate source is available, should a transfer be required.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 69

8.2.2 Transfer

Mimic

Event display

Event controls

Display panel
and help screen

Menu options

Should the preferred source fail or be outside acceptable voltage limits, the Liebert STS2/PDU transfers the
input to the alternate source until the problem is rectified in the preferred source. The unit can be set to
automatically transfer the input back to the preferred source or allow the transfer to be done only manually.

8.2.3 Transfer Inhibit

For a transfer to be completed between input sources, the sources must meet certain parameters or the transfer
cannot take place. Uninterrupted transfer between sources is inhibited due to input source failure, sources out of
sync, switch failure or the unit is in bypass mode.

8.2.4 Bypass

The Liebert STS2/PDU can be manually bypassed to allow the power from a source to directly flow to the output
load. This bypass allows the unit’s electronics to be serviced without dangerous voltages being present.

The Liebert STS2/PDU includes key-interlocked maintenance bypass breakers that allow either input source’s
electronics to be bypassed for maintenance without interruption of power to the load. The maintenance bypass
allows all electronics to be isolated from the input, output and bypass connections. Bypass instructions are
available from the touchscreen and are discussed later in this manual.

8.3 Operator Controls

The Liebert STS2/PDU is equipped with an interface to configure and monitor the unit either locally or remotely.
The Color Graphical Display is a touchscreen LCD that provides a color diagram (Mimic) that displays the
current status of the unit. System parameters are displayed and help is available to define events. See Figure 57
below and Figure 56 in 7.0 - Installation Drawings. The touchscreen menus allow the operator to initiate source
transfers, view event and history logs and view bypass and other operational instructions.

Figure 57 Liebert STS2/PDU touchscreen

Touchscreen control buttons allow you to reset alarms, silence the audible alarm, review configurations, event
and history logs, preferred source, startup and bypass procedures and the help menu.

Qualified personnel, with a password, can use these menus to configure parameters, select a preferred source
and do manual source transfers.

Units can be accessed from a terminal or a PC running terminal emulation software attached to the unit.
Through the RS-232 access, you can monitor and configure the unit, plus remotely select a preferred source. See

12.1 - Using the RS-232 Port for instructions on using the RS-232 interface.

Vertiv™ | Liebert® STS2/PDU™ User Manual | Rev. 6 | 10/2017 70

9.0 THEORY OF OPERATION

9.1 General Description

The Liebert STS2/PDU contains all the equipment necessary to prevent an interruption in power flow to the AC
load, should your primary source fail.

9.1.1 Liebert Static Transfer Switch 2/Power Distribution Unit

The Liebert STS2/PDU is a combination automatic static transfer switch and power distribution unit. The Liebert
STS2/PDU shall include two isolation transformers connected to a solid-state, three-pole, dual-position static
transfer switch designed to automatically and manually switch between two synchronized three-phase AC power
sources without an interruption of power to the load longer than 4 milliseconds (1/4 cycle). Input, output, bypass
circuit breakers and a distribution section shall be included to form an integrated system in a single freestanding
enclosure.

The preferred source is the input source that normally carries the load when both sources are available. The
preferred source is selectable by the user from the LCD panel or an optional Remote Source Selection. The
unselected source is referred to as the alternate source and carries the load if the preferred source should fail or
if a manual transfer is initiated.

The unit uses Silicon Controlled Rectifiers (SCRs) connected in paralleled, opposing pairs to function as an AC
switch configuration. Three pairs of SCRs connect the AC load to the selected preferred input source as long as
the preferred source is available. A second set of SCRs stands ready to transfer the AC load to the alternate input
source should the preferred source fail. The switching action is a very fast, break-before-make with less than a
1/4 cycle break in the AC waveform.

During static switch transfers and retransfers, the conduction state of the SCRs is carefully monitored and
controlled to prevent a current path from one source to the other. This technique prevents a faulted source from
feeding into the other good source.

9.1.2 Source Transfer

The Liebert STS2/PDU allows manually initiated transfers between the two sources, providing the alternate
source is within acceptable voltage limits and phase tolerances with the preferred source. You begin a manual
transfer by selecting the inactive source as the preferred source. On a manual transfer, the Liebert STS2/PDU
transfers between the two sources with less than one (1) millisecond interruption of power to the load. The
transfer can only be completed when both sources are available and synchronized within the user-adjustable
phase synchronization window. For sources where the two frequencies are not exactly in phase, manually­initiated transfers are delayed by the Liebert STS2/PDU until the two sources are within the defined phase
synchronization window.

Source selection can also be done remotely using the Remote Source Selection option, if installed.

9.1.3 Automatic Transfer/Retransfer

If the preferred source is out of voltage and/or frequency limits, the load is automatically transferred to the
alternate source. The default transfer voltage limits comply with the limits of the IEEE Std. 446-1995 computer
voltage tolerance envelope.

If the unit is so configured, the load is retransferred automatically to the preferred source after the preferred
source returns to within the acceptable voltage and frequency limits for at least the defined retransfer time delay
and is in phase with the alternate source. You can enable and disable automatic retransfer to the preferred
source through a user configuration setting.

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Automatic Retransfer Inhibited

If the system makes five transfers from the preferred source to the alternate source in a five minute period,
automatic retransfer back to the preferred source is disabled.

To clear this alarm condition, you must assign the alternate source as the preferred source. Also, the
undervoltage detection thresholds may need adjustment. See Source Setpoints on page 102 for instructions on
setting the UV detection.

This alarm also is cleared if the unit transfers to the preferred source due to an alternate source AC voltage
failure (i.e., an emergency transfer.)

9.1.4 Emergency Transfer

To ensure that power remains connected to the load, the Liebert STS2/PDU automatically performs an
emergency transfer from one input source to the other when an outage occurs on the existing source.

The automatic transfer takes place if the other source’s voltage is within acceptable limits and regardless of the
phase difference between the two sources.

Emergency transfers occur with a loss of power on the output of less than 4 ms.

Emergency transfers from the alternate source to the preferred source are not affected by the Auto Retransfer
Enabled/Disabled or Retransfer Delay user settings.

9.1.5 Load Current Transfer Inhibit

The Liebert STS2/PDU senses the load current. If the load current exceeds the preset level deemed to represent
a load inrush or fault condition, the unit’s logic disables manual and automatic transfers, even if the selected
source’s input voltage is outside the acceptable limits. This event triggers an I-Peak alarm. If so configured, the
Load Current Transfer Inhibit is automatically reset after the current and voltage return to within normal
parameters. This reset provides continued protection against a source failure. The Load Current Transfer Inhibit
also can be programmed to require a manual reset. See Step 14 in Source Setpoints on page 102 for details.

9.1.6 SCR Failure

The Liebert STS2/PDU continuously monitors the status of the SCR switching devices for proper operation. In
the event of a shorted SCR on the input source powering the load, the Liebert STS2/PDU automatically triggers
an alarm and trips open the other source isolation breaker. In the event of a shorted SCR on the other input
source, the Liebert STS2/PDU automatically triggers an alarm and trips open the other source isolation breaker.

In the event of an open SCR, the switch automatically triggers an alarm and transfers the load to the other
source. All open and shorted SCR alarm conditions are latched and require the system to be repaired and reset
to restore normal operation.

9.1.7 On/Off Sequence

The Liebert STS2/PDU contains no master On/Off push button control. When connected to the input sources,
the unit’s logic power comes on automatically. The touchscreen is active as long as at least one input source is
energized and the Control Power Disconnect (located inside the static switch) is closed.

9.2 Detailed Component Description

9.2.1 Controls

Operator Interface

The Liebert STS2/PDU Color Graphical Display unit contains a color LCD touchscreen to provide the operator
interface to control and configure the operation of the unit and quickly diagnose problems. A password and an
optional keylock, if installed, are provided for security.

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Hardware

• The Liebert STS2/PDU operator interface in the Color Graphical Display unit is designed to provide all of the information
required to configure and monitor the unit’s operation.

• The control logic performs automatic operations with minimal operator interface.

• Each Liebert STS2/PDU unit is equipped with a color LCD touchscreen.

• The Liebert STS2/PDU can have optional communication ports installed. See 6.0 - Options and 12.0 - Communication
Interfaces for more information on communication options.

• The RS-232 interface is used for configuration and status and event log monitoring.

Firmware

The operator interface enables you to monitor the Liebert STS2/PDU, to configure setpoints for transfers,
monitor system parameters and access event and history logs. The firmware is accessible through the LCD
touchscreen or the RS-232 interface. The firmware includes:

• View and set the preferred source.

• View and configure setpoints.

• View alarms, faults and status.

• The mimic graphical representation of the systems operation.

• Menu driven monitoring and configuration.

• Step-by-step instructions to assist you in the startup, shutdown and bypass operations.

• Help on event messages.

• Touchscreen alarm reset and silence buttons.
Events in the system, both faults and alarms, are detected and displayed on the LCD. See 11.0 - Alarms and Faults for

more information on events.

• A set of event masks can be configured through the LCD to trigger a system response to an event. See 11.1 - Event Mask.

• Report event conditions from other components of the system.

• Monitor and report changes in event condition states. If the event condition’s state changes from inactive to active, a new
event is detected. If the transition is from active to inactive, the event condition has cleared.

• Process new faults and alarms and clear inactive alarms.

• Provide the alarm reset and silence options.

9.2.2 Circuit Breakers and Non-Automatic Circuit Breakers

Input circuit breaker for each source provides over current protection for the Liebert STS2/PDU. Three
non-automatic circuit breakers provide total isolation of the solid-state switching devices with an input
non-automatic breaker for each source and a load isolation non-automatic breaker. Two non-automatic breakers
provide for maintenance bypassing of the solid-state switching devices to either input source.

All breakers in the Liebert STS2/PDU are plug-in types, which allows any breaker to be replaced without
de-energizing the output bus. The breakers have an interlock in the plug-in base, which prevents the switch from
being withdrawn in the CLOSED position. The switch trips OPEN before it disconnects from the plug-in base.

See 14.2.5 - Circuit Breakers for specifications and more information pertaining to the circuit breakers. See
Figures 23 through 36 for circuit breaker locations.

The circuit breaker schedule is provided in Tables 10 through 12.

9.2.3 SCRs

Brick-type SCRs are used rated to carry the full 100% rated load. The unit is a fuseless design with input circuit
breakers providing overcurrent protection.

9.2.4 Logic Modules

The logic contains three separate redundant logic modules. The modules contain the logic necessary to run the
Liebert STS2/PDU and control transfers and shunt trips under all circumstances, without any outside assistance
once set-up and started properly.

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9.2.5 Audible Alarm

An audible alarm is installed on the control board. This alarm is triggered by an alarm condition detected on the
unit. The alarm can be turned off from the touchscreen. Turning off the audible alarm does not clear or reset the
condition that triggered the alarm.

9.2.6 RS-232 Port

An RS-232 serial port is provided to allow an external terminal to be connected as another user interface. See

12.1 - Using the RS-232 Port for more information.

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10.0 OPERATING INSTRUCTIONS

Before unit is placed into service for the first time, after equipment relocation or after the equipment has been
de-energized for an extended period, a thorough equipment inspection and supervised startup by qualified
personnel are strongly recommended. Contact your local Liebert representative or Vertiv Services at
800-543-2378 to arrange for equipment inspection and startup.

After the initial equipment startup, the following operating guidelines can be used for standard equipment
operation. These guidelines should be reviewed for any special equipment modifications, special site conditions or
company policies that may require changes to the standard equipment operation.

All programmable functions are preset at the factory to enable the unit to be brought up without the need to
enter all selectable parameters.

The LCD touchscreen is discussed in more detail in 13.0 - TOUCHSCREEN Display.

See Figures 23 through 36 for circuit breaker locations.

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10.1 Normal System Turn-On

Mimic

Event display

Event controls

Sources

Static
Transfer
Switch

1. Depending on the type of distribution used:

• If equipped with output breaker CB8, open CB8.

• If equipped with output inline panelboards, open panelboard main breakers CB8 and CB9 and, if supplied, CB10 and

CB11.

• If optional subfeed breakers are supplied, open subfeed breakers CB12 and CB13.
See Figures 3 through 6 for location of breakers.
a. Retract the bolts on the key interlocks for CB1 and CB2.
b. Extend the bolts on the key interlocks for CB4 and CB5, thus preventing CB4 or CB5 from being turned ON.

2. Apply source/input power to both Liebert STS2/PDU inputs by closing CB6 and CB7.
The touchscreen control panel should become active and operate properly when at least one of the inputs is energized.

3. Verify that nominal input voltages are applied to both inputs (Source 1 and Source 2).
The input voltages, selected preferred source, breaker and switch status and alarms are indicated on the Mimic screen.

Figure 58 Liebert STS2/PDU touchscreen

4. Close CB1.

5. Verify that Source 1 voltages are nominal and that CB1 breaker status is correctly indicated on the Monitor/Mimic screen.

6. Close CB2.

7. Verify that Source 2 voltages are nominal and that CB2 breaker status is correctly indicated on the Mimic screen.

8. Verify that boxes for the preferred source and corresponding Liebert STS2/PDU are highlighted on the Mimic screen,
indicating which side of the Liebert STS2/PDU is on.

9. Close Output Breaker CB3 (for redundant output configurations, also close CB3A).

10. Verify that CB3, the Output box and the Load box are highlighted, indicating that CB3 is closed and the STS output is
energized. On units with I-line panelboard, the panelboard is also energized.

NOTE

For redundant output configurations, CB3 descriptions apply to CB3 and CB3A.

11. Press the RESET button on the touchscreen to reset any previous alarms.

12. Check the Event Display and the Mimic to verify there are no active alarms. If any active alarms are displayed, refer to 11.0 -
Alarms and Faults for a description of the alarms and possible causes. Correct all active alarm conditions before
proceeding.

13. If unit is equipped with output breaker CB8, close CB8. The output and load are energized.

14. If unit is equipped with output inline panelboards, close panelboard main breakers CB8 and CB9 and, if supplied, CB10 and
CB11. Turn on panelboard breakers. If optional subfeed breakers are supplied, close subfeed breakers CB12 and CB13.

15. Turn on the load equipment as directed in the load equipment manufacturer’s recommendations.

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10.2 Manual Transfer / Preferred Source Selection

The Source Transfer option (Source Xfers) in the touchscreen menu allows you to select a preferred source.
Transfers are only permitted when the voltage and current are within their proper operating range and the
sources are synchronized. The Source Transfer screen indicates the synchronization between the two sources,
while the voltage and frequency are displayed on the Mimic. See Figure 59. Transfer is inhibited if the deviation
exceeds the parameter set in Source Setpoints. See User Settings on page 101.

NOTE

If one source will be de-energized for an extended period (hours or days), set the Liebert STS2/PDU to bypass
mode for the remaining source. Without using bypass, if a failure occurs in the switch components for the
remaining source, the Liebert STS2/PDU does not have a second source to switch to and the load would not
receive power. See 14.2.12 - Maintenance Bypass for bypass instructions.

Figure 59 Source Transfer screen

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To manually select the preferred source:

1. Close the input breakers CB6, CB7, CB1 and CB2.

2. Select SOURCE XFERS from the menu bar.
The Select Preferred Source screen is displayed in the Event Display.

3. Check the Mimic to verify that Source 1 and Source 2 input voltages are correct.

4. Select SOURCE 1 or SOURCE 2 as your preferred source.
This source is now monitored as the preferred source throughout the various configurations set up through the

touchscreen.

5. Verify that the correct source is designated as the preferred source and that the input source changes to the desired
source.

The Mimic is updated to indicate the new preferred source. The source is now highlighted with blue and that
source is labeled as the preferred source. If the Transfer Inhibit message is displayed, check for alarm messages
on the Active Status window. Correct alarm conditions before attempting a source transfer.

NOTE

The preferred source may also be changed via the optional Remote Source Selection option, thereby initiating a
transfer remotely

10.3 Enabling Remote Source Selection

If your system is equipped with the optional Remote Source Selection option, it must be enabled.

From the Color Graphical Display:

1. Select CONFIG from the menu bar.

2. Select SYSTEM SETTINGS from the Configuration menu.

3. Select SYSTEM OPTIONS from the System Settings menu.

4. Select YES for the REMOTE SOURCE SELECT choice.

10.4 Maintenance Bypass

The Liebert STS2/PDU is equipped with two key-interlocked, bypass breakers, CB4 and CB5, to allow manual
bypass of the switch electronics for either input source in the event of switch failure or for maintenance of the
switch. Refer to Figure 3. While operating on maintenance bypass, all voltages are removed from the static
transfer switch electronics to facilitate safe repair, without de-energizing the load using a make-before-break
switching sequence.

However, the unit can be bypassed using a make-before-break switching sequence only to the same source to
which that the switch is connected, as indicated by the highlighted static transfer switch box on the Mimic
screen.

In the event of source or switch failure, the unit should be bypassed only to the current input source. For
convenience, instructions for the bypass procedure can be displayed on the touchscreen by selecting the BYP.
PROC option from the menu bar.

The Mimic is used to verify the status of the unit during the bypass procedures. In the unlikely event that the
Color Graphical Display is not available, open the front door and look through the slots in the control door. If you
can see green LEDs on the gate driver board through that slot, then the unit is connected to the source
referenced on the label below that slot. See Figure 60.

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Figure 60 Gate board viewing slot locations

Green LEDS on the
Gate Driver Board are
viewable through this
slot indicate that the
STS is on Source 1

GREEN LEDS ON THE
GATE DRIVER BOARD
ARE VIEWABLE
THROUGH THIS SLOT
INDICATE THAT THE
STS IS ON SOURCE 1

Viewing Slot
for the Source 1
Gate Drive Board

Touchscreen

GREEN LEDS ON THE
GATE DRIVER BOARD
ARE VIEWABLE
THROUGH THIS SLOT
INDICATE THAT THE
STS IS ON SOURCE 2

Viewing Slot
for the Source 2
Gate Drive Board

10.4.1 Bypass Procedures for Source 1

To bypass the switch for Source 1:

NOTE

If you wish to bypass the Source 1 static transfer switch but Source 2 is presently active, you must first
transfer to Source 1. See 10.2 - Manual Transfer / Preferred Source Selection.

1. Verify Source 1 is supplying power via the Mimic.

• If the Color Graphical Display is not available, check the gate driver board LEDs through the slots in the control panel.

See Figure 60.

2. Remove interlock key from CB5 and place it in the CB4 interlock.

3. Open the alternate source input breaker CB2.

4. Rotate and remove the CB2 interlock key.

5. Insert the key in the CB4 bypass breaker interlock.

6. Rotate interlock keys in CB4 bypass breaker interlock to retract interlock.

7. Close bypass breaker CB4.

8. Verify the breaker status on the Mimic screen.

9. Open source input breaker CB1.

10. Rotate the CB1 interlock key and remove it to lockout the breaker.

11. Secure the key, per your site’s lockout/tagout procedure.

12. Open output breakers CB3 and CB3A (if supplied) to remove power and isolate the static switch from the load.

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To return to normal mode:

1. Remove the key from CB5 and insert it in the CB1 breaker interlock.

2. Rotate key to retract interlock.

3. Close source input breaker CB1.

4. Verify the Source 1 and CB1 breaker status on the Mimic screen.

5. Select the SOURCE 1 button in the SOURCE XFERS menu.

6. Close output breakers CB3 and CB3A (if supplied).

7. Verify CB3 and CB3A breaker status on the Mimic screen.

8. Verify that STS SOURCE 1 and OUTPUT boxes are highlighted on the Mimic screen.

9. Open bypass breaker CB4.

10. Rotate the keys in CB4 interlock to extend the interlock.

11. Remove the proper key from CB4 interlock and insert it into CB2 breaker interlock.

12. Rotate the key to retract the CB2 breaker interlock.

13. Close source input breaker CB2.

14. Verify the STS SOURCE 2 box and CB2 breaker status on the Mimic screen.

• If the Color Graphical Display is not available, check the gate driver board LEDs through the slots in the control panel.

See Figure 60.

10.4.2 Bypass Procedures for Source 2

To bypass the switch for Source 2:

NOTE

If you wish to bypass the Source 2 static transfer switch but Source 1 is presently active, you must first
transfer to Source 2. See 10.2 - Manual Transfer / Preferred Source Selection.

1. Verify Source 2 is supplying power via the Mimic.

• If the Color Graphical Display is not available, check the gate driver board LEDs through the slots in the control panel.

See Figure 60.

2. Remove the interlock key from CB4 and place it in CB5 interlock.

3. Open the alternate source input breaker CB1.

4. Rotate and remove the CB1 interlock key.

5. Insert the key in the CB5 bypass breaker interlock.

6. Rotate interlock keys in the CB5 bypass breaker interlock to retract the interlock.

7. Close bypass breaker CB5.

8. Verify the breaker status on the Mimic screen.

9. Open source input breaker CB2.

10. Rotate the interlock key and remove it to lockout the breaker.

11. Secure the key, per your site’s lockout/tagout procedure.

12. Open output breakers CB3 and CB3A (if supplied) to remove power and isolate the static switch from the load.

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To return to normal mode:

1. Insert the key in the CB2 breaker interlock.

2. Rotate the key to retract the interlock.

3. Close source input breaker CB2.

4. Verify Source 2 and CB2 breaker status on the Mimic screen.

5. Select the SOURCE 2 button in the SOURCE XFERS menu.

6. Close output breakers CB3 and CB3A (if supplied).

7. Verify CB3 and CB3A breaker status on the Mimic screen.

8. Verify that STS SOURCE 2 and OUTPUT boxes are highlighted on the Mimic screen.

9. Open bypass breaker CB5.

10. Rotate the keys in CB5 interlock to extend the interlock.

11. Remove the proper key from CB5 interlock and insert it into CB1 breaker interlock.

12. Rotate the key to retract the CB1 breaker interlock.

13. Close source input breaker CB1.

14. Verify the STS SOURCE 1 box and CB1 breaker status on the Mimic screen.

• If the Color Graphical Display is not available, check the gate driver board LEDs through the slots in the control panel.

See Figure 60.

10.5 Normal System Shutdown

The Liebert STS2/PDU can be shut down from either the static switch mode or the bypass mode.

10.5.1 Shutdown in Static Transfer Switch Mode

When the Liebert STS2/PDU is operating on static transfer switch mode (not maintenance bypass mode):

1. Turn off the load equipment per manufacturer’s recommendations.

2. Open CB8 or panelboard breakers and mains if supplied

3. Open CB3 to turn off the static switch output.

• Open CB3A if the Liebert STS2/PDU has a redundant output configuration.

4. Open the input switches CB1 and CB2.

5. To completely de-energize the unit, open CB6 and CB7.

10.5.2 Shutdown in Maintenance Bypass Mode

When the Liebert STS2/PDU is operating on bypass:

1. Turn off the load equipment per manufacturer’s recommendations.

2. Open CB8 or panelboard breakers and main if supplied

3. Open the bypass switch (CB4 or CB5) to turn off the static transfer switch output.

4. To completely de-energize the unit, turn open CB6 and CB7.

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11.0 ALARMS AND FAULTS

Alarms and faults are events that are triggered when the operation of the Liebert STS2/PDU falls outside of the
defined parameters. These events can also be triggered by: user actions, such as changing configurations,
clearing logs, etc.; failed components such as a fan failure, an SCR that is open or shorted, etc.; and system status,
such as open circuit breakers, load on alternate source, etc. These events can provide a warning or trigger the
system to make a change, such as switch sources or the recording of a history log.

The Liebert STS2/PDU monitoring system detects and annunciates a comprehensive set of fault and alarm
conditions. Faults and alarm messages are can be viewed on the LCD touchscreen or via the RS-232 port.

On the LCD touchscreen, the events are shown in the Status Display panel in the lower left corner of the
touchscreen and written to the Event log. You can touch a message to view a definition of an event and a tip for
troubleshooting. See 13.0 - TOUCHSCREEN Display for more information about the touchscreen.

If you are monitoring the system through the RS-232 port, see Tab le 14 for the commands to view event logs and
alarm and fault lists.

Event actions can be triggered by the settings configured from the Event Masks. See 11.1 - Event Mask for more
information.

Faults — A fault indicates that a component of the Liebert STS2/PDU has failed or has been damaged. In the
Event Display, faults are indicated in red.

Alarms — An alarm is an event caused by a significant abnormal system condition. In the Event Display, alarms
are indicated in yellow. The setpoints for many of the alarms are configurable through the User Settings. Many
alarms clear themselves when the condition is resolved. If an alarm event mask is set to latch, the alarm
messages remain active until the alarm condition has been corrected and the RESET button is pushed. See 11.1 -
Event Mask for more information on latching.

When the system is equipped with an external modem and a telephone line is connected to the modem, the
system can be programmed to automatically dial out upon occurrence of any of certain designated alarms. The
auto-dial feature can be configured for alarms using the Event Mask option in the touchscreen. See Configuring

the Modem on page 106 for instructions on for setting up a modem.

11.1 Event Mask

The Liebert STS2/PDU gathers, processes and reports faults and alarms, collectively referred to below as events.
The Event Mask dialog box allows you to set the system’s response for specific alarms and faults that are
generated.

The following mask types are available for each event:

• Latch — If a latch is enabled for the selected event, that event remains active even if the originating event condition
clears. A latched event may only be cleared by pushing the RESET button.

• Dial Out — If the selected event is triggered, the system automatically calls the specified telephone numbers through a
modem. For example, a page could be sent or an event could be sent to a external terminal, via a modem. See 12.0 -
Communication Interfaces for more information on configuring communications options.

• Event Log — The selected event is date/time stamped and recorded to the Event Log when the event is triggered.

• Audible — If the selected event is triggered, an audible beeper or horn is sounded by the
Liebert STS2/PDU. The beeper continues while this event is active or latched or until the SILENCE button is pushed.

See Event Masks on page 100 for instructions on setting the mask type via the touchscreen. See the 12.1.4 ­Setting Event Masks with the Terminal for instructions on configuration using the RS-232 port.

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11.2 Event and History Logs

The system tracks events through the Events Log and tracks significant events through the History Logs. These
logs allow you to quickly spot trends or diagnose problems that the unit may have had. Both logs are written in
nonvolatile memory.

The logs can be accessed from the touchscreen menu or the RS-232 port. See 13.7.1 - Logs for more instructions
on viewing the logs from the touchscreen. See Tab le 14 for the RS-232 interface commands used to access the
logs.

11.2.1 Event Log

The events are tracked in sequence of occurrence. The sequence of occurrence is identified by date, time and
frame number. The last 512 events are stored in a nonvolatile memory and can be viewed from the Event Log.

Event logs wrap, meaning when the log is full, the oldest event is deleted when a new event is written to the log.

The Event Log tracks:

• # — the sequence number in which the event occurred since the log was last cleared.

• Message — the event that occurred, such as Ambient Over temp., Source 1 Fail, etc.

• Type — either a Fault or Alarm. See 11.0 - Alarms and Faults for further details on these events.

• ID — the event identifier.

• Date and Time — when the event occurred.

• Faults — the number of fault events logged.

• Alarms — the number of alarm events logged.

• User Alarms — the number of alarm events logged that were triggered by user-created alarms, such as those alarms
created with the Input Contact Isolator settings.

• Total — the sum of all the events currently logged.

11.2.2 History Log

When a designated major alarm occurs, the History Status buffer is frozen, capturing 64 sequential frames before and
after the alarm condition. When the History Status buffer is frozen, a History Log is created.

Two History Logs are available to track major alarms. This log includes the triggering event plus the surrounding
events and the system voltages, currents, frequency, power, source selection and breaker positions at the time of
the event. The History Log displays the 64 sequential frames, in 4-millisecond intervals, of the Present Status
screens surrounding the event.

If you are viewing the log from the touchscreen, the Mimic and the Event Display show the data that was present
as the alarm was triggered. The data is displayed as frames are played.

The History Log allows you to replay the events leading up to the alarm and the events right after the alarm to
see the status of the switch at that time and diagnose the cause of the alarm. The History Log is triggered when
certain events are tripped that have the Freeze option enabled.

You can run through the frames sequentially. The sequence of the events is identified by date, time and frame
number. The History Log frames are stored in a nonvolatile memory buffer that is continuously overwritten until
a designated fault condition occurs. When the fault occurs to trigger a freeze, the History Log stores the next 23
frames, then freezes until it is reset. The History Log then keeps 40 frames before the fault, the frame where the
fault occurred, plus the next 23 frames.

The History Log should not be reset until the fault condition that caused the buffer to freeze is reviewed and
investigated by a qualified service technician. After the alarm condition has been corrected, the History Log can
be cleared.

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The History Log has the following fields:

• Replay Rate — indicates how long it takes for the replay to play. Use the UP and DOWN buttons to set the time.

• Status — the status of the Liebert STS2/PDU at the point of the current frame in the replay. The History log has three
statuses: Frozen, Not Frozen and Retrieving Data, please stand by.

• Critical Event — The event which triggered this log to be written. The event is indicated in red on the bar graph.

• Frame Number — the current frame in the replay. A negative number indicates the replay is at a point before the
triggering event occurred.

11.3 Alarm Notes

The I-PK on Source 1 and I-PK on Source 2 alarms inhibit automatic transfer due to an overload or load fault.
These alarms can be set for either auto or manual alarm reset.

In the auto reset mode, the alarm is reset as soon as the load current and source voltage return to normal and
the user manually presses the RESET button. In either case, the cause of the Source 1 or Source 2 Ipeak overload
should be investigated and resolved (such as by reducing the overload condition or clearing the output fault)
before returning the switch to normal operation.

These events indicate a device failure. The device must be replaced and the system must be restarted for the fault
to clear. A shorted SCR automatically trips open a source input switch (CB1 or CB2) to prevent transfers in the
event of an SCR failure. The SCR failure must be investigated and repaired before returning the switch to normal
operation. Both source input switches must be opened (such as when the unit is placed in maintenance bypass for
servicing) before a shorted or open SCR alarm can be reset.

11.4 List of Messages

Table 1 3 lists available event messages, a definition of the event and the functions that are activated with the

event by default. The functions are indicated as follows:

D — The indicated event initiates the Auto-Dial sequence through the optional modem.
A — The indicated event activates the Audible alarm.
F — The indicated event triggers a Freeze of the History Log.
L — The indicated event Latches. A latched alarm remains displayed until the alarm condition has cleared and the RESET

button has been pressed.
E — By default, all faults and alarms are written to the Event Log. See 12.1.4 - Setting Event Masks with the Terminal.

All of these functions, except Freeze, can be reconfigured to trigger for each event, using the Event Mask option.
See 11.1 - Event Mask. The Freeze function is hard-coded and cannot be changed for a event.

Table 13 Event messages

ID Alarm Message Description/Cause Action

1 S1 SCR SHORT One or more of the SCRs for Source 1 have shorted and failed. D, F, A, E

2 S2 SCR SHORT One or more of the SCRs for Source 2 have shorted and failed. D, F, A, E

3 S1 SCR OPEN One or more of the SCRs for Source 1 is open. D, F, A, E

4 S2 SCR OPEN One or more of the SCRs for Source 2 is open. D, F, A, E

5 PRIMARY FAN FAIL

6 CONTROL MODULE FAIL Control logic module has failed. D, A, E

7 PWR SPLY DC A FAIL Power supply DC bus A has failed. D, A, E

8 PWR SPLY DC B FAIL Power supply DC bus B has failed. D, A, E

9 PWR SPLY S1 AC FAIL Power supply Source 1 AC has failed. D, A, E

10 PWR SPLY S2 AC FAIL Power supply Source 2 AC has failed. D, A, E

11 PWR SPLY LOGIC FAIL A power supply module has failed. D, A, E

12 OUT VOLT SENSE FAIL The output volt sense module failed D, A, E

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A primary cooling fan has failed and the unit is now being cooled by a secondary
fan, which is not monitored.

D, A, E

Table 13 Event messages (continued)

ID Alarm Message Description/Cause Action

13 S1 VOLT SENSE FAIL The Source 1 volt sense module failed. D, A, E

14 S2 VOLT SENSE FAIL The Source 2 volt sense module failed. D, A, E

15 S1 SCR SENSE FAIL The Source 1 SCR sense module failed. D, A, E

16 S2 SCR SENSE FAIL The Source 2 SCR sense module failed. D, A, E

17 S1 CURR SENSE FAIL The Source 1 SCR current module failed. D, A, E

18 S2 CURR SENSE FAIL The Source 2 SCR current module failed. D, A, E

19 S1 GATE DRIVE FAIL The Source 1 gate drive module failed. D, A, E

20 S2 GATE DRIVE FAIL The Source 2 gate drive module failed. D, A, E

21 INTERNAL COMM FAIL Internal CAN communications failed. D, A, E

23 CB1 SHUNT TRIP FAIL CB1 shunt trip failed. D, A, E

24 CB2 SHUNT TRIP FAIL CB2 shunt trip failed. D, A, E

27 EQUIPMENT FAN FAIL One of the equipment fans failed D, A, E

28 INPUT 1 SURGE FAIL Source 1 input surge suppression module failed D, A, E

29 INPUT 2 SURGE FAIL Source 2 input surge suppression module failed D, A, E

64 HEATSINK OVERTEMP Heatsink has exceeded the recommended temperature. A, E

65 EQUIPMENT OVERTEMP Cabinet has exceeded the recommended temperature A, E

67 S1 UV Source 1 under voltage, fast detection. A, E

68 S1 UV (RMS) Source 1 under voltage, slow detection. A, E

69 S1 OV Source 1 over voltage A, E

70 S1 OF/UF Source 1 over frequency/under frequency A, E

71 S1 FAIL Source 1 failure. A, E

72 S2 UV Source 2 under voltage, fast detection. A, E

73 S2 UV (RMS) Source 2 under voltage, slow detection. A, E

74 S2 OV Source 2 over voltage. A, E

75 S2 OF/UF Source 2 over frequency/under frequency. A, E

76 S2 FAIL Source 2 failure. A, E

77 S1 OVERCURRENT Source 1 over current. A, E

78 S2 OVERCURRENT Source 2 over current. A, E

79 S1 I-PEAK I-PK on Source 1. D, F, A, E

80 S2 I-PEAK I-PK on Source 2. D, F, A, E

81 SOURCES OUT OF SYNC Source 1 and Source 2 are out of synchronization. A, E

82 LOAD ON ALT SOURCE The output load is running on the alternate source. A, E

83 AUTO REXFER INHIBIT Automatic retransfer is inhibited. A, E

84 CB1 (S1) OPEN Source 1, Circuit Breaker 1 is open. A, E

85 CB2 (S2) OPEN Source 2, Circuit Breaker 2 is open. A, E

86 CB4 (S1 BYP) CLOSED Source 1 on bypass, Circuit Breaker 4 is closed. A, E

87 CB5 (S2 BYP) CLOSED Source 2 on bypass, Circuit Breaker 5 is closed. A, E

88 CB3 (OUTPUT) OPEN Output circuit breaker (CB3) is open. A, E

89 CB3A (OUTPUT) OPEN Output circuit breaker (CB3A) is open. A, E

90 S1 PHASE ROT ERROR Source 1 phase rotation error. A, E

91 S2 PHASE ROT ERROR Source 2 phase rotation error. A, E

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Table 13 Event messages (continued)

ID Alarm Message Description/Cause Action

92 TRANSFER INHIBITED Transfer inhibited. A, E

93 OUTPUT UV Output is under voltage. D, F, A, E

94 HISTORY LOG FULL

96 INPUT 1 OV INPUT Source 1 over voltage A, E

97 INPUT 1 UV INPUT Source 1 under voltage A, E

98 INPUT 2 OV INPUT Source 2 over voltage A, E

99 INPUT 2 UV INPUT Source 2 under voltage A, E

100 LOAD OVERCURRENT Output over current A, E

101 GROUND OVERCURRENT Ground over current A, E

102 NEUTRAL OVERCURRENT Neutral over current A, E

103 LOAD VOLTAGE THD Voltage THD has exceeded the set limit A, E

104 INPUT 1 CB6 OPEN Source 1 input Circuit Breaker 6 is open A, E

105 INPUT 2 CB7 OPEN Source 2 Input Circuit Breaker 7 is open A, E

106 INPUT 1 OF/UF Source 1 over frequency/under frequency A, E

107 INPUT 2 OF/UF Source 2 over frequency/under frequency A, E

120

INPUT CONTACT #1

121

INPUT CONTACT #2

122

INPUT CONTACT #3

123

INPUT CONTACT #4

124

INPUT CONTACT #5

125

INPUT CONTACT #6

126

INPUT CONTACT #7

127

INPUT CONTACT #8

128 CONFIG MODIFIED A setpoint configuration has changed.

129 PASSWORD CHANGED The password for touchscreen access has been modified and saved.

130 TIME REPROGRAMMED The system’s time has been reset and saved.

131 DATE REPROGRAMMED The system’s date has been reset and saved.

132 EVENT LOG CLEARED The event log has been erased.

133 HIST LOGS CLEARED Both History Logs have been erased.

134 XFER COUNT CLEARED Transfer counter reset to 0 E

135 KWH COUNT CLEARED KW-Hrs counter reset to 0 E

Both History Logs have been written and no more history logs can be written
without clearing one of the logs

Input Contact # x is an optional alarm input. The alarm name can be
programmed with an alarm name from the Input Contactor Isolator settings
option under the Comm Options. See Configuring the Input Contact Isolator
Settings on page 107. The alarm is sent to Monitor DSP. The LCD logs the alarm
with the programmed name. Monitor DSP logs it with the generic name which is
how it is reported to the SVT query.

A, E

A, E

E

E

E

E

E

E

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12.0 COMMUNICATION INTERFACES

The Liebert STS2/PDU monitoring system offers several choices for communications.

The RS-232 terminal port is standard on all units. The port is inside the front door, to the left of the touchscreen
front panel mounting as shown in Figure 54. This port is primarily used as an alternate user interface to
configure, control and diagnose the system. Commands for the RS-232 port are shown in Table 1 4.

Several other communications options are also available. Those options are located in a Communications
compartment. See Figures 47 and 48 for the location of the communications options.

Connections to the communication ports are made by wiring to terminal boards located in the Communications
compartment. The communications options listed below reference the control wiring drawing for each option.

• Liebert IntelliSlot™ Web/485 Card With Adapter (IS-WEB485ADPT) (optional) — the Liebert IS-WEB485ADPT provides
connectivity to any TCP/IP-based Ethernet network to allow the device to communicate with network management
systems (NMS) via SNMP. Events can be transmitted to the NMS to provide remote status monitoring, plus fault and alarm
detection. The Liebert IS-WEB485ADPT includes an RJ-45 port for an Ethernet connection, via Category 5 cable.

The Liebert IS-WEB485ADPT can also integrate the system with an existing Building Management System (BMS) or out­of-band monitoring, using Modbus, a standard multi-drop protocol. The card has redundant communication paths that
make it possible to connect to a BMS using Modbus while simultaneously communicate to a NMS through SNMP.

See Figure 53 for more information on the Liebert IS-WEB485ADPT. If you have questions about the Liebert
IS-WEB485ADPT, refer to the user guide, SL-52615, available at Liebert’s Web site,

• Input Contact Isolator (ICI) Board (optional) — provides an interface for up to eight user inputs. External messages and
alarms can be routed to the unit, via the ICI. See Configuring the Input Contact Isolator Settings on page 107 for
instructions on configuring the connections. See Figure 51 for wiring details.

• Programmable relay board (PRB) (optional) — up to two PRBs can be installed in the Liebert STS2/PDU to route Liebert
STS2/PDU events to external devices. See Configuring the Programmable Relay Board Settings on page 109 for default
settings and instructions for reconfiguring the relays. See Figure 50 for wiring details.

• Comms Board (optional) — includes a terminal block to provide a DTE connection to an external modem. This board also
provides a direct connection to a Liebert SiteScan terminal, via an RS-422.

Liebert SiteLink-12 or Liebert SiteLink-4 is required for Liebert SiteScan to communicate with the Liebert STS2/PDU. See
Figure 52 for wiring details.

Data link requirements are Full Duplex Asynchronous RS-232 format.

Communications options are also discussed in 6.0 - Options.

www.vertivco.com

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12.1 Using the RS-232 Port

The RS-232 port is configured with a baud rate of 9600 with 8 Data Bits, 1 Stop Bit, No Parity and no hardware
handshaking.

12.1.1 Connecting and Using a Terminal

An RS-232 connection can be used to connect the Liebert STS2/PDU to either a terminal or a PC running
terminal emulation software. If unsure of the cable pin out, see 14.2.10 - Terminal Port Connections.

1. Connect the terminal to the Liebert STS2/PDU by plugging the cable from the terminal into the RS-232 port. This
connection can be made at any time.

2. After making the connection, verify the communications link by pressing <ENTER> on the terminal keyboard.

The interface communications system responds as indicated below:

Repeating command -->
Illegal command!
<?> or <HELP?> displays the RS-232 command set
<?> <command> or <HELP?> <command> displays specific help for the command SVTP-Control>

The SVTP-Control > prompt indicates that RS-232 communications are established.

• If you receive no response or prompt, verify that the connector is properly plugged into the port and the PC or terminal
serial interface is working properly.

3. Enter the desired commands, as listed in Tab le 14 .

For additional help type <?> <command> or <HELP?> <command>
Refer to the corresponding menu options in 13.0 - TOUCHSCREEN Display for more details about the

commands.
Some terminal commands require a password. Use the PWD command and a valid password to gain access.

Table 14 Terminal commands

Keys Function

? Displays this help menu or specific help with a command

AA? Displays active alarms

AF? Displays active faults

CEL Clears the event log

CHL Clears the history logs

DATE? Displays current system date

DATE Sets system date

EL? Displays the entire event log

HELP? Displays this help menu or specific help with a command

HLn? Displays the history log #n, if frozen

LOGOUT Logs user out of unprotected mode

PS? Displays the preferred source

PS n Sets the preferred source to #n

PWD Allows users to access protected commands

QUIT Modem only. Ends the session and hangs up the modem.

SH Silences the horn

SPT? Displays all current setpoints

SPTx

SR? Displays status reports

TIME? Displays current system time

TIME Sets system time

UPMDR? Displays metering data

VER? Displays firmware versions

Displays current setpoints for group x. See 12.1.2 - Configuring the Liebert STS2/PDU via the Terminal for a
description of groups.

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12.1.2 Configuring the Liebert STS2/PDU via the Terminal

The SPT command is used to configure the systems setpoints. The SVT syntax for the setpoints consists for
four parameters:

SPT [group] [item] [value] where the parameters are:

• SPT — is the terminal command that is used to configure setpoints.

• group — the group under the setpoint command which contains the desired settings.

• item — the item number within the selected group.

• value — the desired value for this item.

Only the specific options words listed in this section use a hexadecimal value. Other settings, depending on what
they are, use other input types. For example, System ID uses a text string; nominal voltages and currents use
standard numeric integers; and modem baud rate uses an enumeration where

0 = 2400, 1 = 9600, & 2 = 19200 bps.

NOTE

Spaces are placed between each parameter, but not between characters or numbers in a parameter. Using an
underline here to represent a space, an example of a the syntax is: SPT_2_6_0081. The value parameter is

0081.

This section provides instructions for setting these parameters, with an example of building an SPT command
for System and User settings.

Groups Parameter

The setpoints are grouped for ease of configuration. For example, Event Masks are group 4 and System Settings
are group 2. The numbers shown below are entered for the group parameter. For example, start of a System
Settings command is SPT 2.

The group parameters are:

1 = System Ratings
2 = System Settings
3 = User Settings
4 = Event Mask Settings

For example, the start of a System Settings command is SPT 2, where SPT is the system setpoints command and
2 is the group parameter for System Settings.

See 12.1.4 - Setting Event Masks with the Terminal for instructions on configuring Event Mask parameters.

Item Parameter

Each setting within the group is indexed by an item number as shown below in Tab le 16 . These item numbers
are also displayed on the terminal when you list the configuration setting for a particular group.

Continuing with the example, to configure an Options_1 setting under System Settings, the command would
begin with SPT 2 6 where 6 is the value Options_1. Note the space between each parameter.

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Value Parameter

Item settings, depending on what they are, use various value types.Tab le 15 provides a list of the possible value
types and their description.

Table 15 Value types

Type Definition

Numeric

Scaled

String

Enumeration

Bit-packed

Event Masks

An integer numeric value in the units indicated by the item name. For example, a System Voltage Rating of 480
would indicate 480 volts.

Similar to the Numeric, this value type is an integer that has been scaled, usually to remove decimal points that
would normally appear within the value. In this case, a value of 2.5 may actually be input as simply 25. For all Scaled
types, the scaling appears in Ta bl e 1 6.

Certain settings are represented by alphanumeric character strings, such as setting the System Model Number to
ProductName.

This type uses an indexed list to represent possible choices. One example is the Modem Baud Rate which uses a
value of 0 to select 2400 bps, 1 for 9600 bps and 2 for 19200 bps.

This type of value uses a hexadecimal binary word, where each of the sixteen bits in the word has the value of 1
(True) or 0 (False). Although somewhat difficult to use, it packs a large amount of data within a single entry. A
detailed description of this type appears in section 12.1.3 - Setting Bitpacked Options With the Terminal.

This type is a specially formatted and is used to customize the behavior of each fault and alarm in the system. See

12.1.4 - Setting Event Masks with the Terminal for instructions on configuring Event Mask parameters.

Table 1 6 shows the various groups, the settings contained within and the type of value it requires.

Table 16 Group settings and values

Group Item: Description Value Type Value Notes

1 Input Volts (PDU) Integer Set per system spec.

Group 1:
System
Ratings

Group 2:
System
Settings

2 Volts Integer Set per system spec.

3 Current Integer Set per system spec.

4 Frequency Scaled Desired freq. x 10 (600 = 60 Hz)

1 Language Enumeration [Not supported at this time]

2 System Model Number String 14 Character max.

3 System ID Number String 8 Character max.

4 System Tag Number String 8 Character max.

5 System Order Number String 8 Character max.

6 Options_1 Bitpacked 14 Character max.

7 Autodial Primary Line String 20 Character max.

8 Autodial Secondary Line String 20 Character max.

9 Autodial Pager Number String 20 Character max.

10 Autodial Pager PIN String 10 Character max.

11 Modem Init String String 20 Character max.

12 Modem Baud Rate Enumeration 0 = 2400, 1 = 9600, & 2 = 19200 bps

13 Modem LGS Check - Day Bitpacked

14 Modem LGS Check - Time Bitpacked

15 Comms Options 1 Bitpacked See section 12.1.3.

16 Comms Options 2 Bitpacked See section 12.1.3.

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