Emerson NX User Manual

AC Power
For Business-Critical Continuity™

Liebert® NX

Operation and Maintenance Manual – 225-600kVA, Three-Phase, Single-Module & Multi-Module

™

CONTACTING EMERSON NETWORK POWER FOR SUPPORT

To contact Emerson Network Power Liebert Services for information or repair service in the United
States, call 800-543-2378. Liebert Services offers a complete range of star-up services, repair services,
preventive maintenance plans and service contracts.

For repair or maintenance service outside the 48 contiguous United States, contact Liebert Services,
if available in your area. For areas not covered by Liebert Services, the authorized distributor is
responsible for providing qualified, factory-authorized service.

For Liebert Services to assist you promptly, please have the following information available:

Part numbers: _________________________________________________________________

Serial numbers:________________________________________________________________

Rating: _______________________________________________________________________

Date purchased: _______________________________________________________________

Date installed:_________________________________________________________________

Location: ______________________________________________________________________

Input voltage/frequency:________________________________________________________

Output voltage/frequency: ______________________________________________________

DC source reserve time: ________________________________________________________

Product Warranty Registration

To register for warranty protection, visit the Service and Support section of our Web site at:

www.liebert.com

Click on Product Registration and fill out the form.

TABLE OF CONTENTS

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

SAVE THESE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

1.1 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2 Modes of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2.1 Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2.2 Bypass Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2.3 Battery Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2.4 Maintenance Bypass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.3 Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.0 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

2.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.2 Touchscreen Navigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2.1 Main Display Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2.2 Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.3 Events Log Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.4 Measures Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.5 Battery Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.2.6 Life Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.2.7 Settings Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.3 Animated One Line Mimic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.3.1 Rectifier Functional Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.3.2 About Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.4 Modes of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.4.1 Load on Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.4.2 Input Power Failure—Load on DC Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.4.3 Off DC Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.4.4 Remote Emergency Power Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.5 Manual Operations—All Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.5.1 Startup—Single Module System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

2.5.2 Startup-1+N System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

2.5.3 Load Transfer and Retransfer-Single Module System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

2.5.4 Maintenance Bypass Load Transfers-Single Module System: If Load is on UPS Bypass . . . 20

2.5.5 Maintenance Bypass Load Transfers-Single Module System: If Load is on Maintenance

Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2.5.6 1+N System: Transfer load from UPS to Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2.5.7 1+N System: Transfer load from Bypass to UPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2.5.8 Shut Down-Single Module UPS System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2.5.9 1+N System Shutdown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2.5.10 Load Transfer-1+N System: Remove a UPS from System (Collective) . . . . . . . . . . . . . . . . . . 23

2.5.11 Load Transfer-1+N System: Add a UPS to the System (Collective) . . . . . . . . . . . . . . . . . . . . 23

i

2.6 Automatic Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2.6.1 Overloads (Without Transfer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2.6.2 Automatic Transfers to Bypass (Overload Condition) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2.6.3 Automatic Transfers to Bypass, UPS System Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2.6.4 Automatic Retransfers to UPS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

3.0 OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

3.1 Remote Alarm Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.2 MopUPS Shutdown and Monitoring Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.3 Manage UPS Adapter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

3.4 Connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

3.4.1 Available Selectable Input Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3.4.2 Available Selectable Output Contacts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.0 MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

4.1 Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

4.2 Liebert Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.2.1 Professional Startup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.3 Routine Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.3.1 Record Log. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.3.2 Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.3.3 Limited Life Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

4.4 Battery Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

4.4.1 Battery Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

4.5 Detecting Trouble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4.5.1 Items to check include: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4.6 Reporting a Problem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4.7 Upstream Feeder Circuit Breaker Setting Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

5.0 SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

5.1 DC Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

5.1.1 Battery Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

5.2 Other DC Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

5.3 Environmental Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

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FIGURES

Figure 1 Typical single module UPS system one-line diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Figure 2 Main component locations-225 to 300kVA Liebert NX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3 Main components, 400-600kVA Liebert NX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 4 Main display screen, typical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 5 Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 6 Utility fail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 7 Load on bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 8 Status. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 9 Measures menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 10 Battery parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 11 Life menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 12 Settings Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 13 Load on bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 14 Load on bypass, UPS available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 15 Load on UPS, bypass available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 16 Input power fail, load on DC source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 17 Load on UPS, DC source not available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 18 Remote Emergency Power Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

TABLES

Table 1 Measurements for functional blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Table 2 Current-versus-time curves of overload capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Table 3 Connectivity combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 4 UPS component service life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 5 Battery voltage, nominal and float . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 6 Battery retorque values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Table 7 Environmental specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Table 8 Physical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 9 Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

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iv

IMPORTANT SAFETY INSTRUCTIONS

!

!

!

SAVE THESE INSTRUCTIONS

This manual contains important instructions that should be followed during installation of your
Liebert NX UPS. Read this manual thoroughly, paying special attention to the sections that apply to
your installation, before working with the UPS. Retain this manual for use by installing

personnel.

WARNING

Risk of electric shock. Can cause equipment damage, injury or death.
This UPS has several circuits that are energized with high DC as well as AC voltages. Check

for voltage with both AC and DC voltmeters before working within the UPS. Check for voltage
with both AC and DC voltmeters before making contact.

Only properly trained and qualified personnel wearing appropriate safety headgear, gloves,
shoes and glasses should be involved in installing the UPS or preparing the UPS for
installation. When performing maintenance with any part of the equipment under power,
service personnel and test equipment should be standing on rubber mats.

In case of fire involving electrical equipment, use only carbon dioxide fire extinguishers or
those approved for use in fighting electrical fires.

Extreme caution is required when performing installation and maintenance.
Special safety precautions are required for procedures involving handling, operation and

maintenance of the UPS system. Observe all safety precautions in the installation manual,
SL-25535, and in this manual before as well as during performance of all maintenance
procedures. Observe all DC safety precautions before working on or near the DC system.

Important Safety Instructions

WARNING

Risk of heavy unit falling over. Improper handling can cause equipment damage, injury or
death.

Exercise extreme care when handling UPS cabinets to avoid equipment damage or injury to
personnel. The UPS module weight is up to 4450lb. (2019kg).

Locate center of gravity symbols and determine unit weight before handling each
cabinet. Test lift and balance the cabinets before transporting. Maintain minimum tilt from
vertical at all times.

Slots at the base of the module cabinets are intended for forklift use. Base slots will support
the unit only if the forks are completely beneath the unit.

Read all of the following instructions before attempting to move, lift, or remove packaging
from unit, or prepare unit for installation.

WARNING

Risk of electric shock and fire. Can cause equipment damage, personal injury or death.
Under typical operation and with all UPS doors closed, only normal safety precautions are

necessary. The area around the UPS system should be kept free of puddles of water, excess
moisture and debris.

Only test equipment designed for troubleshooting should be used. This is particularly true for
oscilloscopes. Always check with an AC and DC voltmeter to ensure safety before making
contact or using tools. Even when the power is turned Off, dangerously high potential electric
charges may exist at the capacitor banks and at the DC connections.

All wiring must be installed by a properly trained and qualified electrician. All power and
control wiring must comply with all applicable national, state and local codes.

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 to summon help in case of an accident.

1Liebert

®NX™

Important Safety Instructions

!

Battery Cabinet Precautions

The following warning applies to all battery cabinets supplied with UPS systems. Additional
warnings and cautions applicable to battery cabinets may be found in Important Safety

Instructions on page 1 and 4.4 - Battery Maintenance.

WARNING

Risk of electric shock, fire and smoke. Can cause equipment damage, injury and death.
Internal battery strapping must be verified by manufacturer prior to moving a battery cabinet

after initial installation.

• Battery cabinets contain non-spillable batteries.

• Keep units upright.

• Do not stack.

• Do not tilt.
Call 1-800-LIEBERT before moving battery cabinets after initial installation.
For systems using DC sources other than batteries, refer to the manufacturer’s

recommendations for handling and care.

NOTE

Materials sold hereunder cannot be used in the patient vicinity (e.g., use where UL, cUL or
IEC 60601-1 is required). Medical applications such as invasive procedures and electrical life
support equipment are subject to additional terms and conditions.

NOTICE

This unit complies with the limits for a Class A digital device, pursuant to Part 15 Subpart J
of the FCC rules. 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. Operation of this unit in a residential area may cause
harmful interference that the user must correct at his own expense.

Liebert®NX

™

2

1.0 INTRODUCTION

DC

Bus

BFB

CB1

(N ote 5 )

UPS Module

2 Wire +GND

(See Note 2 )

3 Wire + GND

1. UPS rectifier bypass input and output cables must be run in separate conduits.

2. All power cables from DC supply should be sized for a total maximum of 2V drop at
maximum discharge current.

3. Control wiring and power wiring must be run in separate conduits.

4. Emerson recommends installing grounding conductors .

5. Standard configuration has CB1 removed. If CB1 is required, option must be ordered.

To DC Supply

Module Rectifier
AC Input

Module Bypas s
AC Input

UPS Output

3 Wire + GND

3 Wire + GND

Critical

Load

1.1 General Description

The Liebert NX UPS provides continuous, high-quality AC power to your business-critical equipment,
such as telecommunications and data processing equipment. The Liebert NX UPS supplies power
that is free of the disturbances and variations in voltage and frequency common to utility power,
which is subject to brownouts, blackouts, surges and sags.

The Liebert NX utilizes the latest in high-frequency, double-conversion pulse-width modulation
technology and fully digital controls to enhance its reliability and increase the ease of use.

As shown in Figure 1, the AC utility source is input to the rectifier converts the AC utility into DC
power. The inverter converts that DC power from the utility—or DC power from the DC source—into
AC power for the load. The DC source will power the load through the inverter in the event of a power
failure. The utility source can also power the load through the static bypass.

If maintenance or repair of the UPS is necessary, the load can be switched without interruption in
service to the optional maintenance bypass.

Figure 1 Typical single module UPS system one-line diagram

Introduction

3Liebert

®NX™

1.2 Modes of Operation

1.2.1 Normal Mode

Operating in normal mode, the Liebert NX’s rectifier derives power from a utility AC source and
supplies regulated DC power to the inverter, which regenerates precise AC power to supply the
connected equipment. The rectifier also uses the utility source power to charge the DC sources.

1.2.2 Bypass Mode

When the Liebert NX is in bypass mode, the load is directly supported by utility power and is without
DC source backup protection.

The Liebert NX
mode without an interruption in AC power if the inverter is synchronous with the bypass and any of
the following occurs:

• Inverter fails

• Inverter overload capacity is exceeded

• Inverter is manually turned Off by the user

NOTE

If the inverter is asynchronous with the bypass, the static switch will transfer the load from the
inverter to the bypass WITH interruption in AC power to the critical load. This interruption
will be less than 10ms. This interruption time may be altered by modifying the Output transfer
interrupt time setting.

’

s inverter and bypass static switch will shift the load from the inverter to bypass

Introduction

1.2.3 Battery Mode

When utility AC power fails, the Liebert NX protects the critical load by instantaneously channeling
DC source power to the inverter, which continues supporting the critical load without interruption.

When utility power returns and is within acceptable limits, the Liebert NX automatically shifts back
to Normal mode, with the rectifier powering the critical load.

1.2.4 Maintenance Bypass

The installation of a Maintenance Bypass Cabinet or Assembly is recommended to allow you to totally
isolate the UPS from all power sources. Use of the Maintenance Bypass is described in 2.0 -
Operation.

Liebert®NX

™

4

1.3 Options

A number of options are available from Emerson® for your UPS system. Some options are not
available for all ratings. Described below are the most frequently provided options. Other options are
available. Contact your Emerson sales representative for more information.

• Battery and Racks—The batteries provide power in the event of a power outage. The Liebert
NX UPS can use a variety of battery types, provided the battery plant is designed for the UPS DC
voltage range and the load requirements of your application.

• Battery Cabinets—Valve-regulated, lead-acid (VRLA) sealed batteries are available in
matching cabinets for convenient installation and maintenance in otherwise unprotected space.
Depending on the UPS module rating, two or more cabinets may be connected in parallel to
provide the additional run time.

• Module Battery Disconnect—The UPS system utilizes a separate Module Battery Disconnect
for remotely located batteries. A sensing circuit in the UPS module, set at the battery low voltage
limit, trips the Module Battery Disconnect to safeguard the battery from excessive discharge. The
Module Battery Disconnect has an undervoltage release mechanism designed to ensure that
during any shutdown or failure mode all battery potential is removed from the UPS system.

• Maintenance Bypass—This switchboard provides make-before-break maintenance bypass. It
includes: Maintenance Bypass Breaker (MBB) and Maintenance Isolation Breaker (MIB).

• Load Bus Synchronization—The Load Bus Sync (LBS) option keeps independent UPS systems
(and therefore their critical load buses) in sync, even when the modules are operating on DC
source or asynchronous AC sources. This means that critical loads connected to both load buses
can switch seamlessly between the two.

• Temperature-Compensated Charging—When the battery temperature exceeds a preset limit
(typically 77°F [25°C]), this optional circuit proportionally reduces float charging voltage to
prevent overcharging the battery.

• Battery Load Testing-When activated, this option forces the battery string to assume the load
for a short period of time.

Introduction

5Liebert

®NX™

2.0 OPERATION

The Liebert NX UPS is equipped with a microprocessor-based display touchscreen designed for
convenient and reliable operation. The display is driven by menu-prompted software.

2.1 Features

The Liebert NX interface display enables the operator to perform such tasks as:

• Quickly check operational status

• Monitor the power flow through the UPS system and all meter readings

• Execute operational procedures

• Check status reports and event files

• Adjustment programmable parameters

The touchscreen display has a blue-background and multicolored text. The display turns On
automatically, but dims and the backlight goes out after 15 minutes of inactivity. Touching the screen
will reactivate the backlight for 15 minutes. If any screen other than the mimic screen is accessed,
that screen will be displayed for 5 minutes without any interaction. If there is no activity for
5 minutes, the display will revert to the basic mimic screen.

Figure 2 Main component locations-225 to 300kVA Liebert NX

Operation

HMI Screen

Optional Main
Input Circuit

Breaker (CB1)
Backfeed
Circuit Breaker

FRONT DOORS REMOVED

Bypass Busbars
Ø A,B,C

Rectifier Input
Busbars Ø A,B,C

Output
Busbars Ø A,B,C

Input
Ground
Busbar

Battery
Busbars (+/-)

DOORS AND INNER SKINS REMOVED

Liebert®NX

™

6

Figure 3 Main components, 400-600kVA Liebert NX

HMI Screen

Main Input Circuit
Breaker (CB1)
Optional

Backfeed Circuit
Breaker (BFB)

External
Communication
Panel

Operation

Bypass Busbars
Ø A,B,C

Rectifier Input
Busbars Ø A,B,C

Output
Busbars Ø A,B,C

Battery
Busbars (+ / -)

Input
Ground Busbar

FRONT DOORS REMOVED

DOORS AND INNER SKINS REMOVED

7Liebert

®NX™

Figure 4 Main display screen, typical

9

1

5

3

2

8

4

7

6

1. Bypass Input: voltage and frequency readings

2. Line power Input: voltage, current and fre­quency readings

3. Output: voltage, current and frequency read­ings

4. Battery: voltage and current readings

5. System Status

6. Control Buttons

7. Menu Buttons

8. Animated One Line Mimic

9. About Button

Critical

Load

BFB

UPS Module

To DC Supply

Module Rectifier
AC Input

Module Bypass
AC Input

UPS Output

DC

Bus

BFB

UPS Module

To DC Supply

Module Rectifier
AC Input

Module Bypass
AC Input

UPS Output

DC

Bus

Critical

Load

Operation

Figure 5 Normal Mode

Figure 6 Utility fail

™

Liebert®NX

8

Figure 7 Load on bypass

BFB

UPS Module

To DC Supply

Module Rectifier
AC Input

Module By pass
AC Input

UPS Output

DC

Bus

Critical

Load

2.2 Touchscreen Navigation

Several menu items can be accessed from the main display screen (see Figure 9). These menu items
are detailed in subsequent sections.

2.2.1 Main Display Screen

This is the default screen. It displays the following information:

• Bypass Input Voltage

• Bypass Input Frequency

•Input Voltage

• Input Current

• Input Frequency

• Output Voltage

•Output Current

• Output Frequency

• DC Source Voltage

• DC Source Current

Operation

System Status

System Normal Indicator—When the green status box appears, this means that the system is
operating normally and that no warning or alarm has occurred. During line power failures (with all
other conditions being nominal), this box is replaced by a yellow triangle.

Warning Indicator—This indication is activated by the presence of abnormal conditions which
could affect the normal operation of the UPS. These conditions do not originate with the UPS, but
may be caused either by the surrounding environment or by the electrical installation (line power side
and load side). A description of the active warning(s) can be viewed by clicking on the yellow triangle
or using the Status button at the bottom of the page.

Fault Indicator—When the red circle with white cross appears, immediate attention should be
given to the severity of the alarm, and service should be called promptly. A description of the active
alarm(s) can be viewed by clicking on the Status button at the bottom of the page.

Regardless of which indicator is active, all available diagnostic information on the unit can be
displayed by touching this area.

Control Buttons: Start Inverter and Stop Inverter—The touchscreen display features two
buttons for starting and shutting down the inverter. The start/stop control incorporates a safety
feature for preventing accidental operation. When the start or stop function for the inverter is
selected, a pop-up window appears asking for confirmation of the action.

Reset Fault—Reset faults (becomes red when there is a system fault).

Alarm Silence—Silence the buzzer in the case of an alarm.

NOTE

If screen is inactive for 30 seconds, the LCD will revert to this page.

9Liebert

®NX™