Precision Cooling
For Business-Critical Continuity™
Liebert Mini-Mate2
™
User Manual - 2 & 3 Tons, 50 & 60Hz
TABLE OF CONTENTS
IMPORTANT SAFETY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
PRODUCT NUMBER NOMENCLATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
1.1 Designed to Match Computer and Electronic Equipment Needs—From Installation
to Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.0 STANDARD FEATURES—2 & 3 TON SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2.1 Evaporator Section - Split Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Condensing Unit Section—Split Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.1 Indoor Centrifugal Fan Condensing Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.2 Outdoor Prop Fan Condensing Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.3 Indoor Water/Glycol Condensing Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Chilled Water Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4 System Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.4.1 Other Standard Control Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.0 OPTIONAL FACTORY-INSTALLED FEATURES—EVAPORATOR/CHILLED WATER UNITS . . . . . . 9
3.1 Reheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Humidifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3 Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.4 Switches and Motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.5 Free-Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.6 Optional Configurations—Prop Fan Condensing Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.7 Optional Configurations—Water/Glycol Condensing Units . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.8 Optional Configurations—Chilled Water Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.0 SHIP-LOOSE ACCESSORIES—FIELD-INSTALLED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1 Remote Monitoring, Autochangeover and Leak Detection Equipment. . . . . . . . . . . . . . . . . 12
5.0 SITE PREPARATION AND INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1 Installation Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.1 System Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.2 Room Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.1.3 Location Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2 Ceiling Unit Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.3 Equipment Inspection—Upon Receipt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.4 Packaging Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.5 Installing the Ceiling Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.5.1 Close-Coupled Installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.5.2 Evaporator Air Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.5.3 Piping Connections and Coolant Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.5.4 Condensate Pump Kit Installation—All Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.5.5 Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
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5.6 Indoor Air-Cooled Centrifugal Fan Condensing Unit Installation . . . . . . . . . . . . . . . . . . . . 30
5.6.1 Location Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.6.2 Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.6.3 Piping Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.6.4 Ducting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.7 Outdoor Air Cooled Condensing Unit Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5.7.1 Location Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5.7.2 Piping Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.7.3 Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.8 Water and Glycol Cooled Condensing Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
5.8.1 Location Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
5.8.2 Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.8.3 Piping Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.9 Optional Equipment Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.9.1 Free-Cooling Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.9.2 Hot Water Reheat Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5.10 Checklist for Completed Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6.0 MICROPROCESSOR CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
6.1 Feature Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
6.2 Main Menu <Menu>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.3 Setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.4 Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.5 Active Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.6 Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.7 Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.8 Setback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.9 Setup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.9.1 Restart Time Delay. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.9.2 C/F Degrees. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.9.3 Humidity Control Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.10 Change Passwords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.11 Calibrate Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.12 Alarm Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.13 Alarm Time Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.14 Common Alarm Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.15 Custom Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
6.15.1 Standard Custom Alarm Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
6.16 Custom Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
6.17 Run Diagnostics (Available On Rev 1.001.0 and Higher) . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
7.0 SYSTEM PERFORMANCE MICROPROCESSOR CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . .53
7.1 Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
7.1.1 Cooling/Heating Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
7.1.2 Cooling Operation (Cooling, Compressorized Direct Expansion and Chilled Water). . . . . . . 53
7.1.3 Heating Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
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7.2 Humidity Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7.2.1 Dehumidification/Humidification Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7.2.2 Dehumidification Operation, Compressorized Direct Expansion (DX) Systems . . . . . . . . . . 55
7.2.3 Humidification Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7.3 Load Control Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7.3.1 Communication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
8.0 ALARMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.1 Standard Alarms: Definitions and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.1.1 Custom Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.1.2 High Head Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.1.3 Humidity Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.1.4 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.1.5 Humidifier Problem Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.1.6 High Water Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.1.7 Loss of Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8.1.8 Short Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
8.2 Optional/Custom Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
8.2.1 Change Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
8.2.2 High Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
8.2.3 Smoke Detected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
9.0 SYSTEM TESTING AND MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
9.1 System Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.1.1 Environmental Control Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.1.2 Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.1.3 Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.1.4 Humidification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.1.5 Dehumidification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.1.6 High Temperature Sensor—Optional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.1.7 Smoke Detector Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.1.8 Remote Shutdown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.2 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
9.2.1 Electric Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
9.2.2 Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
9.2.3 Direct Drive Blower Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
9.2.4 High Static Belt Drive Blower Package (Option) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
9.2.5 Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
9.2.6 Humidifier Circuit Board Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
9.3 Replacement Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
9.3.1 Compressor Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
9.3.2 Electrical Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
9.3.3 Replacing the Humidifier Canister . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
10.0 MAINTENANCE INSPECTION CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
11.0 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
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FIGURES
Figure 1 Model number nomenclature—Evaporator units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Figure 2 Model number nomenclature—Air-cooled, indoor condensing units . . . . . . . . . . . . . . . . . . . . . . . . 3
Figure 3 Model number nomenclature—Outdoor air-cooled prop fan condensing units . . . . . . . . . . . . . . . . 4
Figure 4 Model number nomenclature—Water/glycol-cooled condensing units. . . . . . . . . . . . . . . . . . . . . . . 4
Figure 5 Model number nomenclature—Chilled water units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 6 Wall-box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 7 Free-cooling arrangement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 8 Air-cooled systems, 2 and 3 tons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 9 Water/glycol-cooled systems, 2 and 3 tons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 10 Chilled water systems, 3 tons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 11 Threaded rod and hardware kit installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 12 Refrigerant piping diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 13 Dimensions, evaporator and chilled water units with direct drive blower . . . . . . . . . . . . . . . . . . 24
Figure 14 Dimensions, evaporator units with optional belt drive blower assembly . . . . . . . . . . . . . . . . . . . 25
Figure 15 Evaporator and chilled water unit piping data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 16 Evaporator and chilled water unit electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 17 Close-coupled installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Figure 18 Indoor air-cooled centrifugal condenser dimensions and pipe connections . . . . . . . . . . . . . . . . . . 32
Figure 19 Centrifugal condenser electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 20 Cabinet and floor planning dimensional data, outdoor condensing unit. . . . . . . . . . . . . . . . . . . . 34
Figure 21 General arrangement (air- cooled condensing unit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 22 Cabinet dimensions and piping data, water/glycol indoor condensing module. . . . . . . . . . . . . . . 37
Figure 23 General arrangement, water/glycol split systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Figure 24 Optional free-cooling coil (3-way valve) on water/glycol units . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Figure 25 Optional hot water reheat (two-way valve) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 26 Control key locations—all-mounted display box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Figure 27 Control menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Figure 28 Control board (inside evaporator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Figure 29 Wall box board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Figure 30 Ground current detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Figure 31 Hot gas bypass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
iv
TABLES
Table 1 System configurations - 60Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 2 System configurations - 50Hz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 3 Application limits, evaporator and chilled water units * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 4 Application limits, indoor and outdoor air-cooled condensing units . . . . . . . . . . . . . . . . . . . . . . . 13
Table 5 Application limits, indoor water/glycol-cooled condensing units . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 6 Ceiling unit weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 7 Cooling unit air flow at 0.3 IWG (75PA) ESP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 8 Recommended refrigerant line sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 9 Pipe length and condenser elevation relative to evaporator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 10 Line charges - refrigerant per 100 ft. (30m) of Type L copper tube . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 11 Refrigerant charge in Liebert pre-charged R-407C line sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 12 Equivalent lengths for various pipe fittings, ft (m). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Table 13 Refrigerant charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 14 Connection sizes and torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 15 Net weights—evaporator and chilled water units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 16 Net weight, high static blower module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 17 Indoor condensing unit airflow, CFM at 0.5 iwg esp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 18 Centrifugal condenser dimensions, weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 19 Dimensions and net weights—air-cooled outdoor condensing units . . . . . . . . . . . . . . . . . . . . . . . 35
Table 20 Net weight, indoor water/glycol-cooled condensing unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 21 View default setpoints and allowable ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Table 22 Microprocessor night and weekend setback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Table 23 Setup functions, default values and allowable ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Table 24 Alarm default time delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Table 25 Switch settings (wall box board) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Table 26 Equipment switch settings (unit control board) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Table 27 Cooling and dehumidification load response of hot gas bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Table 28 External static pressure available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Table 29 Typical discharge pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Table 30 DIP switch settings for humidifier control board (2- and 3-ton unit . . . . . . . . . . . . . . . . . . . . . . . 65
Table 31 Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
v
vi
IMPORTANT SAFETY INSTRUCTIONS
!
!
!
!
!
SAVE THESE INSTRUCTIONS
This manual contains important safety instructions that should be followed during the installation
and maintenance of the Liebert Mini-Mate2. Read this manual thoroughly before attempting to
install or operate this unit. Only qualified personnel should move, install or service this equipment.
Adhere to all warnings, cautions and installation, operating and safety instructions on the unit and in
this manual. Follow all installation, operation and maintenance instructions and all applicable local
and national building, electrical and plumbing codes.
WARNING
Arc flash and electric shock hazard. Disconnect all electric power supplies and wear protective
equipment per NFPA 70E before working within electric control enclosure. Failure to comply
can cause serious injury or death.
Customer must provide earth ground to unit, per NEC, CEC and local codes, as applicable.
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.
The Liebert microprocessor control does not isolate power from the unit, even in the Unit Off
mode. Some internal components require and receive power even during the Unit Off mode.
The line side of the disconnect switch on the front of the unit contains live high-voltage. The
only way to ensure that there is NO voltage inside the unit is to install and open a remote
disconnect switch and check the internal power supply wires with a voltmeter. Refer to unit
electrical schematic. Follow all applicable local and national electric codes.
Important Safety Instructions
WARNING
Risk of explosive discharge from high-pressure refrigerant. Can cause injury or death.
This unit contains fluids and gases under high pressure. Relieve pressure before working with
piping.
WARNING
Risk of refrigerant system rupture or explosion from overpressurization. Can cause
equipment damage, injury or death.
If a pressure relief device is not provided with the condenser unit, the system installer must
provide and install a discharge pressure relief valve per local and national codes in the high
side refrigerant circuit. Do not install a shutoff valve between the compressor and the field
installed relief valve. Do not isolate any refrigerant circuits from overpressurization
protection.
WARNING
Risk of high-speed moving parts. Can cause injury or death.
Open all local and remote electrical power disconnect switches before working in the unit and
component electrical enclosures.
CAUTION
Risk of contact with hot surfaces. Can cause injury.
The compressors, refrigerant discharge lines, humidifiers and reheats are extremely hot
during unit operation. Allow sufficient time for them to cool before working within the unit
cabinet. Use extreme caution and wear protective gloves and arm protection when working on
or near hot compressors, discharge lines, humidifiers and reheats.
1Liebert
®
Mini-Mate2
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Important Safety Instructions
!
!
CAUTION
Risk of leaking water. Can cause equipment and building damage.
This unit requires a water drain connection. It may also require an external water supply to
operate. Improper installation, application and service practice can result in water leakage
from the unit. Water leakage can result in severe property damage and loss of critical data
center equipment. Do not locate unit directly above any equipment that could sustain water
damage. Emerson recommends installing leak detection equipment for unit and supply lines
and in the secondary drain pan. Check drain lines periodically for leaks, sediment buildup,
obstructions, kinks and/or damage and verify that they are free running.
CAUTION
Risk of sharp edges, splinters and exposed fasteners. Can cause injury.
Only properly trained and qualified personnel wearing appropriate safety headgear, gloves,
shoes and glasses should attempt to move the unit, lift it, remove packaging from or prepare
the unit for installation.
NOTICE
Risk of a leaking coil due to freezing and/or corrosion. Can cause equipment and serious
building damage.
Cooling coils and piping systems that are connected to open cooling towers or other open
water/glycol systems are at high risk for freezing and premature corrosion. Fluids in these
systems must contain the proper antifreeze and inhibitors to prevent freezing and premature
coil corrosion. The water or water/glycol solution must be analyzed by a competent water
treatment specialist before startup to establish the inhibitor requirement. The water or
water/glycol solution must be analyzed every six months to determine the pattern of inhibitor
depletion. The complexity of water-caused problems and their correction makes it important
to obtain the advice of a water treatment specialist and follow a regularly scheduled
maintenance program.
NOTICE
Risk of damage from forklift. Can cause unit damage.
Keep tines of the forklift level and at a height suitable to fit below the skid and/or unit to
prevent exterior and/or underside damage.
NOTICE
Risk of improper storage. Can cause unit damage.
Keep the Liebert Mini-Mate2 upright, indoors and protected from dampness, freezing
temperatures and contact damage.
Liebert® Mini-Mate2
™
2
PRODUCT NUMBER NOMENCLATURE
MM
D = Disconnect Switch
0 = No Disconnect Switch
MM = Liebert Mini-Mate2
Refrigerant
7 = R-407C
D36 7 A H A
Blower Type
D = Direct Drive
Internal Blower
B = Belt Drive
External Blower
Supply Power
P = 208/230V - 1 ph - 60Hz
X = 277V - 1 ph - 60Hz
S = 220V - 1 ph - 50Hz (3-ton only)
A = 460V - 3 ph - 60Hz (3-ton only)
Y = 208/230V - 3 ph - 60Hz (3-ton only)
M = 380/415V - 3ph - 50Hz (3-ton only)
E
Unit Type
E = Split Evaporator
K = Split Evaporator with Free-Cooling
ED
Humidification
H = Canister Humidifier
0 = No Humidifier
R = Remote Humidifier Contact
J = Canister Humidifier and Remote
Humidifier Contact
Reheat Type
0 = No Reheat
E = Electric Reheat
S = SCR Reheat (not available
with free-cooling)
Sensor Packages
0 = None
A = Filter Clog
B = Smoke Sensor
C = High-Temperature Sensor
D = Filter Clog & Smoke Sensor
E = Filter Clog & High-Temperature Sensor
F = Smoke Sensor & High-Temperature Sensor
G = Filter Clog, Smoke Sensor & High-Temperature Sensor
Nominal Capacity
MC
D = Disconnect Switch
0 = No Disconnect Switch
MC = Liebert Mini-Mate2 indoor condensing units
Refrigerant
7 = R-407C
H = Hot Gas
Bypass
D36 L A H 7
Head Pressure Controls
L = Liebert Lee-Temp
™
Receiver
Supply Power
P = 208/230V - 1 ph - 60Hz
X = 277V - 1 ph - 60Hz
S = 220V - 1 ph - 50Hz (3-ton only)
A = 460V - 3 ph - 60Hz (3-ton only)
Y = 208/230V - 3 ph - 60Hz (3-ton only)
M = 380/415V - 3ph - 50Hz (3-ton only)
A
Cooling Method
A = Air-Cooled
Nominal Capacity
24 = 2-ton, 60Hz
35 = 3-ton, 50Hz
36 = 3-ton, 60Hz
Figure 1 Model number nomenclature—Evaporator units
Product Number Nomenclature
Figure 2 Model number nomenclature—Air-cooled, indoor condensing units
3Liebert
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Mini-Mate2
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Product Number Nomenclature
PFH
Nominal Capacity, kBtuh
PF = Prop Fan Condensing Unit with Hot Gas Bypass
P = 208/230V - 1ph - 60Hz
Y = 208/230V - 3ph - 60Hz (3-ton only)
A = 460V - 3ph - 60Hz (3-ton only)
B = 575V - 3ph - 60Hz (3-ton only)
S = 220V - 1ph - 50Hz (3-ton only)
M = 380/415V - 3ph - 50Hz (3-ton only)
037A PL7
L = 95°F Ambient,
Liebert Lee-Temp
™
H = 105°F High Ambient,
Liebert Lee-Temp
0 = Std. Sound Level
Z = Quiet-Line
— = Standard Coil
C = Coated Coil
Cooling Method
A = Air-Cooled
Refrigerant
7 = R-407C
—
MC
D = Disconnect Switch
0 = No Disconnect Switch
MC = Liebert Mini-Mate2
indoor condensing
units
Refrigerant
7 = R-407C
H = Hot Gas Bypass
D38 2AH7
Head Pressure Controls
2 = 2-Way Standard Pressure Water Reg Valve
3 = 3-Way Standard Pressure Water Reg Valve
D = 2-Way High-Pressure Water Reg Valve
T = 3-Way High-Pressure Water Reg Valve
Supply Power
P = 208/230V - 1 ph - 60Hz
X = 277V - 1ph - 60Hz
S = 220V - 1ph - 50Hz (3-ton only)
A = 460V - 3ph - 60Hz (3-ton only)
Y = 208/230V - 3ph - 60Hz (3-ton only)
M = 380/415V – 3ph-50Hz (3-ton only)
W
Cooling Method
W = Water/Glycol
Nominal Capacity
26 = 2-ton, 60Hz
37 = 3-ton, 50Hz
38 = 3-ton, 60Hz
Figure 3 Model number nomenclature—Outdoor air-cooled prop fan condensing units
Figure 4 Model number nomenclature—Water/glycol-cooled condensing units
Liebert® Mini-Mate2
™
4
Figure 5 Model number nomenclature—Chilled water units
MM
D = Disconnect Switch
0 = No Disconnect Switch
MM = Liebert Mini-Mate2
Blower Type
D = Direct Drive Internal Blower
B = Belt Drive External Blower
Reheat Type
0 = No Reheat
E = Electric Reheat
H = Hot Water Reheat
D40 3AHEC
Cooling Method
C = Chilled Water
Nominal Capacity
39 = 3-ton, 50Hz
40 = 3-ton, 60Hz
AD
Valve Type
2 = 2-Way Chilled Water Valve
3 = 3-Way Chilled Water Valve
Supply Power
P = 208/230V - 1 ph - 60Hz
X = 277V - 1ph - 60Hz
S = 220V - 1ph - 50Hz
A = 460V - 3ph - 60Hz
Y = 208/230V - 3ph - 60Hz
M = 380/415V – 3ph-50Hz
Humidification
H = Canister Humidifier
0 = No Humidifier
R = Remote Humidifier Contact
J = Canister Humidifier and Remote
Humidifier Contact
Sensor Packages
0 = None
A = Filter Clog
B = Smoke Sensor
C = High-Temperature Sensor
D = Filter Clog & Smoke Sensor
E = Filter Clog & High-Temperature
Sensor
F = Smoke Sensor & High
Temperature Sensor
G = Filter Clog, Smoke Sensor & High-
Temperature Sensor
Product Number Nomenclature
5Liebert
®
Mini-Mate2
™
Introduction
1.0 INTRODUCTION
1.1 Designed to Match Computer and Electronic Equipment Needs—From Installation
to Operation
Installed above the ceiling, Liebert Mini-Mate2 Precision Cooling systems control the cooling,
humidity and air distribution required by sensitive electronic equipment. A range of sizes and
configurations is available to meet varying sites’ needs.
The Liebert Mini-Mate2 is also easy to use. Advanced microprocessor technology allows easy, precise
control, and menu-driven monitoring keeps you informed of system operation through the LCD
readout. These features, combined with Emerson quality construction and reliable components,
guarantee satisfaction from installation through operation.
Liebert Precision Cooling
Liebert Precision Cooling systems are designed to control the environment required for computers
and other sensitive electronic equipment. The Liebert Mini-Mate2 provides complete control on an
around-the-clock basis and the high sensible heat ratio required by sensitive electronic equipment.
Easy Installation
The Liebert Mini-Mate2 is a split-system evaporator combined with an air-, water- or glycol-cooled
condensing unit or is a self-contained, chilled water unit. Each split system has thermostat-type
wiring to controls and condensing unit. System components are pre-charged with refrigerant and can
be connected together with optional pre-charged line sets or optional sweat adapters for field
refrigerant piping.
Easy to Service
Low-maintenance components are easily accessed through removable front panels. Spare parts are
always in Emerson inventory and available on short notice.
Advanced Control Technology
A menu-driven microprocessor control system provides precise temperature and humidity control and
accurate alarm setpoints. Using touch-sensitive buttons, the wall-mounted monitor/control panel
allows you to select and display temperature and other monitored parameters.
High Efficiency
High sensible heat ratio, scroll compressor and precise microprocessor control allow the system to
operate efficiently.
Space Saving Design
All indoor components are installed above the ceiling, so no floor space is required.
Reliable
The Liebert Mini-Mate2 family installed base is a testimony to the system reliability. Components
include a rugged scroll compressor, high-efficiency copper tube, aluminum-fin evaporator coil and a
double inlet, direct drive fan.
Agency Listed
Standard 60Hz units are CSA certified to the harmonized U.S. and
Canadian product safety standard, CSA C22.2 No 236/UL 1995 for
“Heating and Cooling Equipment” and are marked with the CSA c-us logo.
Location
When considering installation locations, consider that these units contain
water and that water leaks can cause damage to sensitive equipment
below. Do not mount these units above sensitive equipment. A fieldsupplied pan with drain must be supplied beneath cooling units and water/glycol condensers.
Do not mount units in areas where normal unit operating sound might disturb the working
environment.
Liebert® Mini-Mate2
™
6
2.0 STANDARD FEATURES—2 & 3 TON SYSTEMS
2.1 Evaporator Section - Split Systems
The evaporator section is designed for ceiling installation. The cabinet and chassis are constructed of
heavy gauge galvanized steel. The unit can be serviced using only one side increasing its versatility in
mounting locations. Mounting brackets are factory-attached to the cabinet. Internal cabinet
insulation meets ASHRAE 62.1 requirements for Mold Growth, Humidity & Erosion, tested per
UL 181 and ASTM 1338 standards.
The evaporator section includes the evaporator coil, R-407C unit charge, filter-drier, factory-mounted
disconnect switch, two-speed direct-drive blower assembly and microprocessor control with wallmounted control box. The unit is provided with supply and return air openings for field-supplied
ducting or supply/return plenum. Evaporators can be configured with canister humidifier and/or
reheat. An indoor or outdoor condensing unit must be selected for each evaporator.
2.2 Condensing Unit Section—Split Systems
2.2.1 Indoor Centrifugal Fan Condensing Units
Indoor Air-Cooled Centrifugal Fan Condensing Units include scroll compressor, factory-mounted
disconnect switch, condenser coil, R-407C unit charge, belt-driven centrifugal blower assembly,
high-pressure switch, Liebert Lee-Temp
line solenoid valve. Unit must be mounted indoors. Condensing unit is designed to use outdoor air
with temperatures ranging from -30°F to 95°F (-34°C to 35°C).
™
head pressure control system, hot gas bypass and liquid-
Standard Features—2 & 3 Ton Systems
2.2.2 Outdoor Prop Fan Condensing Units
Outdoor Prop Fan Condensing Units include scroll compressor, condenser coil, R-407C unit charge,
prop fan, liquid-line solenoid valve, high pressure switch, Liebert Lee-Temp head pressure control
and hot gas bypass. Condensing unit is designed for outdoor locations with operating ambients
ranging from -30°F to 95°F (-34°C to 35°C).
2.2.3 Indoor Water/Glycol Condensing Units
Indoor Water/Glycol Condensing Units includes scroll compressor, R-407C unit charge,
factory-mounted disconnect, coaxial condenser, hot gas bypass, high head pressure switch and
two-way water regulating valve designed for 150psi (1034.3kPa). Condensing units can be used on
either a water or glycol cooling loop.
2.3 Chilled Water Units
Chilled Water Units are designed for ceiling installation. The cabinet and chassis are constructed of
heavy gauge galvanized steel. The unit can be serviced using only one side increasing its versatility in
mounting locations. Mounting brackets are factory-attached to the cabinet. Internal cabinet
insulation meets ASHRAE 62.1 requirements for Mold Growth, Humidity & Erosion, tested per
UL 181 and ASTM 1338 standards. Chilled water models are self-contained and include a chilled
water coil, two-speed, direct-drive centrifugal blower, factory-mounted disconnect switch and twoway, slow-close motorized valve. Design pressure is 300psi (2068kPa), 60psi (414kPa) close-off
differential.
7Liebert
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Mini-Mate2
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2.4 System Controls
System controls include a microprocessor control board mounted in the evaporator/chilled water unit
and a wall-mounted interface with a two-line, 16-character liquid crystal display. An eight-key,
membrane keypad for setpoint/program control, unit On/Off, fan speed and alarm silence is below the
LCD screen. It provides temperature setpoint and sensitivity adjustment, humidity setpoint and
sensitivity adjustment, digital display of temperature, humidity, setpoints, sensitivities, fan speed
and alarm conditions.
The wall-box is field-wired to the microprocessor control using standard four-conductor thermostat
wire (field-supplied). The temperature and humidity sensors are in the wall box, which can be
installed up to 300 feet (91.4m) from the evaporator unit. The unit-mounted control board also
includes common alarm terminals and shutdown terminals. The unit automatically restarts after a
power outage.
Figure 6 Wall-box
Standard Features—2 & 3 Ton Systems
2.4.1 Other Standard Control Features
• Adjustable auto restart • Calibrate sensors
• 5 day/2 day setback • Predictive humidity control
• Password protection • Common alarm output
• Alarm enable/disable • Remote shutdown terminals
• Self-diagnostics
Liebert® Mini-Mate2
™
8
Optional Factory-Installed Features—Evaporator/Chilled Water Units
3.0 OPTIONAL FACTORY-INSTALLED FEATURES—EVAPORATOR/CHILLED WATER
UNITS
3.1 Reheat
Electric Reheat includes 304/304 stainless steel finned tubular reheat elements, with high limit
safety switch.
SCR Electric Reheat uses an SCR controller and unit control software to provide full cooling with
modulating of the electric reheat elements to control air temperatures. Reheat capacity is up-sized to
offset the cooling capacity. (The SCR Electric Reheat is not available on chilled water, free-cooling or
575V units.)
Hot Water Reheat includes hot water coil, 2-way solenoid valve and Y-strainer.
NOTE
This option is available only on Chilled Water units, but not with other reheat options.
3.2 Humidifier
The Canister Humidifier includes a steam-generating type humidifier with automatic flushing
circuit, inlet strainer, drain, 1" (25.4mm) air gap on fill line and solenoid valves. Humidifier problem
alarm annunciates at the wall-mounted display panel.
Remote Humidifier Contact allows the unit’s humidity controller to control a humidifier outside
the unit. Power to operate the remote humidifier does not come from the Liebert Mini-Mate2.
Available on units with or without internal humidifier.
3.3 Sensors
Smoke Sensor checks return air, shuts down the unit upon sensing smoke and activates visual and
audible alarms at the wall-box display. This smoke sensor is not intended to function as or replace
any smoke sensor system that may be required by local or national codes.
High-Temperature Sensor senses the return air temperature and shuts down unit if the
temperature reaches 125°F (52°C). This device is not meant to replace any fire detection system that
may be required by local or national codes.
3.4 Switches and Motors
Filter Clog senses pressure drop across the filters and activates visual and audible alarms at the
wall-box display. The wall-box display annunciates the alarm and flashes a notification upon reaching
a customer setpoint.
A Factory-Installed Non-Fused Disconnect Switch allows unit to be turned off for maintenance.
A disconnect switch is standard for the evaporators, chilled water units and indoor condensing units,
but these units may be specified without the switch.
Direct-Drive blower can be factory-eliminated from the evaporator/chilled water cabinet for high
static applications (0.9 to 1.5in. [23 to 38mm] w.g.). See 4.0 - Ship-Loose Accessories—Field-
Installed for the optional, externally mounted high static blower assembly.
9Liebert
®
Mini-Mate2
™
3.5 Free-Cooling
FreeCooling
Coil
Water/Glycol
Condens er
Field Piping
Wat er Temperature
Sensor
Liebert Mini-Mate2
Dry cooler
Free-cooling option: A second
cooling coil allows the system to take
advantage of colder outdoor
temperatures and bypass compressor
operation.
When the water temperature goes
below 45°F (7°C), cooling switches
over to free-cooling operation. A
separate chilled water source can
also be used with air-cooled systems.
Free-cooling option includes separate cooling coil, three-way slow-close valve and separate supply and
return piping. Free-cooling is activated when the water temperature reaches a field-adjustable
temperature, typically 45°F (7°C). The valve is rated for 300psi (2068kPa) working pressure.
Air-cooled condensing units can be matched with evaporators using free-cooling coils with chilled
water sources to serve as backup cooling. When matched with a water/glycol condensing unit, a
three-way water regulating valve is recommended for the condensing unit to simplify piping to the
main supply pipes. The coil is designed for closed-loop applications using properly treated and
circulated fluid. Not available with SCR reheat options.
Figure 7 Free-cooling arrangement
Optional Factory-Installed Features—Evaporator/Chilled Water Units
NOTE
If free-cooling is applied to an open water tower, an optional copper-nickel (CuNi) coil is
required to prevent premature corrosion, or a heat exchanger must separate the tower water
from the free-cooling loop. The copper-nickel coil requires an extended lead time.
3.6 Optional Configurations—Prop Fan Condensing Units
Outdoor Prop Fan Condensing Units are also available in the following optional configurations:
• High ambient models for providing catalog capacities at ambient temperatures up to 105°F
3.7 Optional Configurations—Water/Glycol Condensing Units
3.8 Optional Configurations—Chilled Water Units
Liebert® Mini-Mate2
(40°C).
• Quiet-Line models for low noise level conditions (below 56 dBA) and for providing catalog
capacities at ambient temperatures up to 95°F (35°C).
• Condenser coils can be phenolic-coated for extended coil life in coastal areas.
Indoor Water/Glycol Condensing Units are also available with the following piping options:
• Two-way water reg. valve with 350 psi (2413kPa) design pressure.
• Three-way water reg. valve with 150psi (1034kPa) design pressure.
• Three-way water reg. valve with 350psi (2413kPa) design pressure.
Chilled Water Units are also available with the following valve option:
• Three-way, slow-close, motorized chilled water valve rated for 300 psi (2068 kPa) working
pressure. Valve is non-spring return.
™
10
4.0 SHIP-LOOSE ACCESSORIES—FIELD-INSTALLED
A High Static Blower Assembly can be field-attached to the evaporator to provide up to 2.0"
(51mm) of external static pressure on the discharge side of the evaporator. The blower box contains a
centrifugal-type double-inlet blower. This blower is equipped with a belt drive and 1.5 hp single speed
motor mounted to an adjustable motor base. Note: Unit must be ordered without the internal direct
drive motor and the high static blower disables the two-speed fan operation feature.
Filter box kit (for ducted applications) includes filter box with duct flange connection, one
MERV 8 (ASHRAE 52.2-2007) filter (20"x20"x4" [508mm x 508mm x 102mm]), and a duct flange for
use on the supply air opening of the unit
Air Distribution Plenum includes molded plastic three-way discharge plenum, 16"x25"x4"
(406mm x 535mm x 102mm) MERV 8 filter (ASHRAE 52.2-2007), and sheet metal block-off plates for
covering the duct openings on the evaporator unit. Plenum mounting requires T-bar ceiling grid.
The Condensate Pump is field-mounted external to the cabinet, wired to the unit power block and is
equipped with a check valve. A secondary float can be field-wired to shut down the unit upon high
condensate level.
A Remote Temperature and Humidity Sensor package includes sensors in an attractive case
with 30 ft. (9 m) of cable. Can be wall or duct mounted. Remote sensors should be used when the wall
box is not located in the space to be conditioned.
NOTE
Installing the remote sensors disables the sensors included in the wall box.
Ship-Loose Accessories—Field-Installed
Field-Installed Kits available for filter clog, smoke sensor, high-temperature sensor, electric reheat
and humidifier. The kits include installation instructions and are designed to be added to the
evaporator unit before it is installed in the ceiling. Electric reheat kits cannot be installed in units
with free-cooling.
277-to-208V step-down transformer (37.5 amps) allows use of 277-1-60 supply power with a
208-1-60 Prop Fan Condensing unit. The transformer is coated with epoxy and contained in an
enclosed, non-ventilated electrical box with adaptable mounting brackets.
Single-Point Power Kit contains the necessary electrical components to interconnect the
high-voltage sections of a close-coupled evaporator and an MCD condensing unit.
Pre-Charged Refrigerant Line Set (R-407C) contains an insulated copper suction line and a
copper liquid line for interconnection of the indoor and outdoor sections. Available in 15-foot (4.5m)
and 30-foot (9m) sections.
The Refrigerant-Line Sweat Adapter Kit contains two suction and two liquid line fittings that
allow field-supplied refrigerant piping between the evaporator and condensing unit.
11 Liebert® Mini-Mate2
™
Ship-Loose Accessories—Field-Installed
4.1 Remote Monitoring, Autochangeover and Leak Detection Equipment
The Liebert RCM4™ is a four-point, normally open, dry contact monitoring panel. One Form-C, dry
contact common alarm relay output (rated at 24 VAC, 3 Amp) is provided. Four red LEDs illuminate
on the respective alarm and the alarm buzzer is silenced by a front panel switch. The RCM4 requires
a 24VAC or 24VDC power source. Power supply is not included.
The Liebert AC4
control for up to four Liebert Mini-Mate2 units within a room. The Liebert AC4 will enable redundant
units in an alarm condition, balance usage and test standby units at programmed intervals. Two
common alarm relay outputs are available. A built-in LCD and RS-232 port for direct PC/terminal
connection provides two options for configuration and monitoring of the product. The Liebert AC4
requires 24VAC input power.
The Liebert AC8
enables redundant devices during an alarm condition, balances usage of devices and tests standby
devices at programmable intervals. Supports four zones and can use the 4-20mA temperature sensor
(TW420) for temperature staging in each zone. Two programmable output control relays are available
for auxiliary control such as humidity lockout. Emergency power operation input provided for device
control during an emergency. Two common alarm relay outputs are available. A built-in LCD and
RS-232 port for direct PC/terminal connection provides two options for configuration and monitoring
of the product.
The Liebert ENV-DO
major alarm conditions of Environmental units. The Liebert ENV-DO-ENCL1 packages one
Environmental DO interface card in its own steel enclosure and the ENV-DO-ENCL2 packages two
Environmental DO interface cards in one enclosure for installation external to the Liebert
Mini-Mate2. The self-contained kit includes an external 120VAC-to-24VAC power transformer.
Wiring harnesses are not provided. Power and communication wiring is field-provided.
The Liebert Liqui-tect
liquid using a pair of corrosion-resistant, gold-plated probes mounted in a painted, height-adjustable
enclosure. Dual Form-C, dry contact common alarm relays (rated at 24VAC, 3A) signal a leak
detected as well as loss of power and cable fault. The Liebert Liqui-tect 410 requires an external
24VAC or 24VDC power source.
™
Autochangeover Controller provides autochangeover and autosequence
™
is ideal for coordinated control of systems with redundant units. The Liebert AC8
™
interface card provides 16 discrete outputs, corresponding to status and
®
410 Point Leak Detection Sensor detects the presence of conductive
Liebert LT460 Zone Leak Detection Kits include one LT460 sensor, a specified length of
LT500-xxY cable (maximum length is 100 ft [30.5m]) and a corresponding number of hold-down clips.
The Liebert LT460 requires an external 24VAC, 0.12A power source, such as EXT-XFMR or XFMR24.
Liebert SiteScan
®
is a monitoring solution that gives you decision-making power to effectively
manage the equipment critical to your business.
Liebert SiteScan enables communication from Liebert environmental and power units, as well as
many other pieces of analog or digital equipment, to a front-end software package that provides
real-time status and alarms so you can react quickly to changing situations.
Liebert SiteScan is designed with flexibility for both small systems and large, complex systems such
as those in computer rooms, telecommunications facilities or industrial process control rooms.
Contact your local Emerson representative for assistance with a Liebert SiteScan system.
The NIC-ENCL1 and NIC-ENCL2 package one or two Liebert IntelliSlot
®
Web/485 Cards with
Adapters, respectively, in one steel enclosure for installation external to the Liebert Mini-Mate2. The
Liebert IntelliSlot Web/485 Card with Adapter provides communication with the Liebert
Mini-Mate2
™
via SNMP, HTTP, RTU Modbus 485 and BACnet IP. The self-contained kit includes an
external 120VAC-to-24VAC transformer as a power source. Wiring harnesses are not provided. Power
and communication wiring are field-provided.
Liebert® Mini-Mate2
™
12
5.0 SITE PREPARATION AND INSTALLATION
NOTE
Before installing unit, determine whether any building alterations are required to run piping,
wiring and ductwork. Carefully follow all unit dimensional drawings and refer to the
submittal engineering dimensional drawings of individual units for proper clearances.
5.1 Installation Considerations
The evaporator unit is usually mounted above the suspended ceiling of the space to be conditioned.
Ducted systems may be installed in a different room.
5.1.1 System Configurations
The typical system configuration has a separate evaporator or cooling unit and a condensing unit.
Chilled water systems are self-contained units. Refer to Tables 1 and 2 and to Figures 8, 9 and 10
for different system combinations and unit configurations that are possible.
Table 1 System configurations - 60Hz
Nominal
Capacity
2 Tons MM_24E MC_24A PFH_27A MC_26W
3 Tons
Cooling
Unit
MM_36E MC_36A PFH_37A MC_38W
MM_40C Self-Contained - Chilled Water
Indoor Air-Cooled
Centrifugal fan
Condensing Unit
Outdoor Air-Cooled
Propeller Fan
Site Preparation and Installation
Indoor
Water/Glycol
Table 2 System configurations - 50Hz
Condensing Unit
Nominal
Capacity
3 Tons
Cooling
Unit
MM_35E MC_35A PFH_36A MC_37W
MM_39C Self-Contained - Chilled Water
Indoor Air-Cooled
Centrifugal fan
Outdoor Air-Cooled
Propeller Fan
Indoor Remote
Water/Glycol-Cooled
Table 3 Application limits, evaporator and chilled water units*
Input Voltage Range of Return Air Conditions to Unit
Minimum Maximum Dry Bulb Temperature Relative Humidity
-5% +10% 65°F to 85°F (18°C to 29°C) 20% to 80%
* Unit will operate at these conditions but will not control to these extremes of conditions.
Table 4 Application limits, indoor and outdoor air-cooled condensing units
Input Voltage
Minimum Maximum Minimum Maximum
-5% +10%
* Unit capacity ratings are stated for 95°F (35°C) for standard units and 105°F (41°C) for high ambient PFH units only.
Exceeding these rating points by 20°F (11°C) will result in lower cooling capacities, but will not damage the equipment.
Condensing
Units
Outdoor Prop Fan
Condensing Unit
Indoor Air-Cooled
Condensing Unit
-30°F (-34°C)
Entering Dry Bulb Air Temperature
115°F (46°C) standard unit*
125°F (52°C) high ambient unit*
115°F (46°C)*
Table 5 Application limits, indoor water/glycol-cooled condensing units
Input Voltage Entering Fluid Temperature
Minimum Maximum Minimum Maximum
-5% +10% 65°F (18.3°C) * 115°F (46°C)
* Operation below 65°F (18°C) may result in reduced valve life and fluid noise.
13 Liebert® Mini-Mate2
™
5.1.2 Room Preparation
!
The room should be well insulated and must have a sealed vapor barrier. The vapor barrier in the
ceiling and walls can be a polyethylene film. Paint on concrete walls and floors should contain either
rubber or plastic.
NOTE
The single most important requirement for maintaining environmental control in the
conditioned room is the vapor barrier.
Outside or fresh air should be kept to a minimum when tight temperature and humidity control is
required. Outside air adds to the cooling, heating, dehumidifying and humidifying loads of the site.
Doors should be properly sealed to minimize leaks and should not contain ventilation grilles.
5.1.3 Location Considerations
CAUTION
Risk of leaking water/glycol. Can cause building and equipment damage.
Do not mount units over equipment and furniture that can be damaged by leaking
water/glycol. Install a watertight drain pan with a drain connection under the cooling unit
and water/glycol condenser unit. Route the drain to a frequently used maintenance sink so
that running water can be observed and reported in a timely manner. Post a sign to alert
people to report water flowing from the secondary drain pan.
NOTE
Do not mount units in areas where normal unit operating sound may disturb the working
environment.
Install the evaporator unit over an unobstructed floor space if possible. This will allow easy access for
routine maintenance or service. Do not attach additional devices (such as smoke detectors, etc.) to the
housing, as they could interfere with the maintenance or service.
Site Preparation and Installation
NOTE
Temperature and humidity sensors are in the wall box. Install the wall box where discharge
air DOES NOT blow directly on the sensors.
When using the optional air distribution plenum, avoid locating the evaporator unit in confined areas
that affect the air flow pattern. Such locations could cause short cycles, downdrafts and air noise.
Avoid locating the unit in an alcove or at the extreme end of a long, narrow room. Avoid installing
multiple units close to each other. This could result in crossing air patterns, uneven loads and
competing operating modes.
When installing an air-cooled or water/glycol-cooled unit inside a space, ensure that national and
local codes are met for refrigerant concentration limits that might vary with building type and use.
Liebert® Mini-Mate2
™
14
Figure 8 Air-cooled systems, 2 and 3 tons
Split System Evaporator
Supply and Return Air Plenum
Indoor Air-cooled Condensing Unit
Split System Evaporator
Supply and Return Air Ducted
Indoor Air-cooled Condensing Unit
Split System Evaporator
Supply and Return Air Plenum
Outdoor Air-Cooled Condensing Unit
Split System Evaporator
Supply and Return Air Ducted
Outdoor Air-Cooled Condensing Unit
Split System Evaporator
Supply and Return Air Ducted
Remote Water/Glycol Condensing Unit
Split System Evaporator
Supply and Return Air Plenum
Remote Water/Glycol Condensing Unit
Split System Evaporator
Supply and Return Air Ducted
Remote Water/Glycol Condensing Unit
Condensing Unit
Evaporator
Drycooler
Condensing Unit
Evaporator
Drycooler
Condensing Unit
Evaporator
Condensing Unit
Evaporator
Cooling
Tow er
Split System Evaporator
Supply and Return Air Plenum
Remote Water/Glycol Condensing Unit
Cooling
Tower
Chilled Water
Supply and Return Plenum
Chilled Water Ducted
Site Preparation and Installation
Figure 9 Water/glycol-cooled systems, 2 and 3 tons
Figure 10 Chilled water systems, 3 tons
15 Liebert® Mini-Mate2
™
5.2 Ceiling Unit Weights
!
Table 6 Ceiling unit weights
Weight
Model #
Cooling Units *
MMD24E 225 (102)
MMD35E 225 (102)
MMD36E 225 (102)
MMD39C 230 (104)
MMD40C 230 (104)
Indoor Condensing Units
MCD24A 270 (125)
MCD35A 280 (130)
MCD36A 280 (130)
MCD26W 190 (90)
MCD37W 200 (95)
MCD38W 200 (95)
MCD38W 200 (95)
* Add 20 lb. (9kg) to units with free-cooling or hot water reheat coils.
lb (kg)
Site Preparation and Installation
5.3 Equipment Inspection—Upon Receipt
When the unit arrives, do not uncrate equipment until it is close to its final location. All required
assemblies are banded and shipped in corrugated containers. If you discover any damage when you
uncrate the unit, report it to the shipper immediately. If you later find any concealed damaged, report
it to the shipper and to your Liebert supplier.
5.4 Packaging Material
All material used to package this unit is recyclable. Save it for future use or dispose of the material
appropriately.
5.5 Installing the Ceiling Units
WARNING
Risk of ceiling collapse and heavy unit falling. Can cause building and equipment damage,
serious injury or death.
Verify that the supporting roof structure is capable of supporting the weight of the unit(s) and
the accessories. (see 5.2 - Ceiling Unit Weights.)
Be sure to securely anchor the top ends of the suspension rods. Make sure all nuts are tight.
The evaporator unit and condensing unit are usually mounted above the ceiling and must be securely
mounted to the roof structure. The ceiling and ceiling supports of existing buildings may require
reinforcements. Be sure to follow all applicable national and local codes. Use field-supplied threaded
suspension rods and 3/8-16 factory hardware kit.
Recommended clearance between ceiling grids and building structural members is unit height plus
3 in (76mm).
Install the four field-supplied rods by suspending them from suitable building structural members.
Locate the rods so that they will align with the four mounting holes in the flanges that are part of the
unit base.
Liebert® Mini-Mate2
™
16
Using a suitable lifting device that is rated for the weight of the unit (see 5.2 - Ceiling Unit
3/8" Threaded Rod
(field-supplied )
3/8" Hex Nut
3/8" Washer
Sleeve
Isolator
3/8" Fender Washer
3/8" Hex Nut
3/8" Hex Nut Nylock
Unit Base Pan (ref)
Weights), raise the unit and pass the threaded rods through the four mounting holes in the flanges
that are part of the unit base.
Attach the threaded rods to the unit flanges using the supplied nuts and grommets. (See Figure 11).
The rubber grommets provide vibration isolation.
1. First, use the plain nuts to hold unit in place. Adjust these nuts so that the weight of the unit is
supported evenly by the four rods, does not rest on the ceiling grid, and to ensure the unit is level.
NOTE
The units must be level in order to drain condensate properly.
2. Second, use the shake-proof nuts to “jam” the plain nuts.
Figure 11 Threaded rod and hardware kit installation
Site Preparation and Installation
5.5.1 Close-Coupled Installations
If the evaporator and indoor condensing units are to be mounted back-to-back (close-coupled), hang
each unit before connecting them together. Align four bolt holes in the condensing unit with cage nuts
in the evaporator. Insert rubber spacers and secure with provided hardware. Align the refrigerant
connections and tighten them as described in 5.5.3 - Piping Connections and Coolant
Requirements (see Figure 17).
Close-coupled installations may take advantage of a single-point power kit to allow one power feed to
provide input for both evaporator and condensing units. Kit should be mounted in evaporator unit
before raising unit into ceiling area.
5.5.2 Evaporator Air Distribution
Filter Box
The optional filter box is available for the unit and mounts directly to the return air opening of the
evaporator. The 2 and 3 ton filter box is supplied with a MERV 8 filter (per ASHRAE 52.2-2007)
measuring 20 in. x 20 in. x 4 in. (508x508x102mm).
17 Liebert® Mini-Mate2
™
Site Preparation and Installation
Plenum Installation
The 2- and 3-ton non-ducted evaporators can use the optional ceiling-mounted plenum to provide
four-way air distribution. The plenum fastens to the bottom of the evaporator. The plenum includes a
16 in. x 25 in x 4 in (406x635x102mm) MERV 8 filter (per ASHRAE 52.2-2007).
1. The evaporator should be mounted above the bottom of the T-bar supports with at least 30 in.
(762mm) clearance from return air end to wall (for replacing filter).
2. Check the contents of the plenum kit.
3. Follow the installation instructions included with the plenum kit.
NOTE
Do not operate the unit without filters installed in the return air system.
Connections for Ducted Systems
In a ducted configuration, the direct drive evaporator has a maximum allowable external static
pressure of 0.3" wg (7.6 mm). Use flexible ductwork or non-flammable cloth collars to attach ductwork
to the unit and to help control the transmission of vibrations to building structures. Insulation of
ductwork is vital to prevent condensation during the cooling cycle. The use of a vapor barrier is
required to prevent absorption of moisture from the surrounding air into the insulation.
If the return air duct is short, or if noise is likely to be a problem, sound-absorbing insulation should
be used inside the duct. Ductwork should be fabricated and installed in accordance with local and
national codes.
Table 7 Cooling unit air flow at 0.3 IWG (75PA) ESP
2 Ton
Fan Speed
High 885 (1504) 1250 (2124)
Low 800 (1359) 1000 (1699)
CFM (CMH)
3 Ton
CFM (CMH)
5.5.3 Piping Connections and Coolant Requirements
The following pipe connections are required:
• A drain line from the evaporator coil drain pan (This line also serves as the drain for the optional
humidifier.)
• A drain line from the secondary drain pan beneath the unit.
• A water supply line to the optional humidifier (if applicable).
• Refrigerant piping connections between the evaporator unit and the condensing unit (air, water,
or glycol). If the evaporator unit is chilled water, connections to the building chilled water source
are required.
Drain Line
NOTICE
Risk of water backing up in the evaporator coil drain line. Can cause building and equipment
damage from overflowing water.
Do not install an external trap in the drain line. This line already has a factory-installed trap
inside the cabinet.
This line may contain boiling water. Use copper or other suitable material for the drain line.
A 3/4 in. (19.1 mm) NPT female connection is provided for the evaporator coil condensate drain. This
line also drains the humidifier, if applicable. The drain line must be located so it will not be exposed to
freezing temperatures. The drain should be the full size of the drain connection.
The evaporator drain pan includes a float switch to prevent operation if drain becomes blocked.
Liebert® Mini-Mate2
™
18
Site Preparation and Installation
The optional condensate pump kit is required when the evaporator is installed below the level of the
gravity-fed drain line.
NOTE
Remove any shipping band from the float switch in the evaporator pan before operating unit.
Humidifier Water Supply Line
Units supplied with the optional humidifier package have a 1/4 in. (6.4 mm) compression fitting with
ferrule at the water supply connection Supply pressure range is 10 PSIG to 150 PSIG. Required flow
rate is 1 gpm. A shut-off valve should be installed in this line to isolate the humidifier for
maintenance.
Assembly Instructions
1. Cut tube square and remove cutoff burr.
2. Slide nut then sleeve on tube, threaded end on nut facing end of tube.
3. Insert tube into fitting seating it against stop shoulder and thread nut to body “hand-tight.”
4. With proper wrench tighten 1-1/4 to 2-1/4 turns.
NOTICE
Risk of improper tightening of the piping fittings. Can cause fitting damage and leaks that
can result in building and equipment damage.
Do not over tighten the piping fittings
Chilled Water Loop
On chilled water units, install manual service shutoff valves at the supply and return lines of each
unit. These shutoff valves are used for routine service or emergency isolation of the unit.
Chilled water supply and return lines must be insulated. Insulating them will prevent condensation
of the water supply and return lines to the unit.
The minimum recommended water temperature is 42¡F. Design pressure is 300psig (2068 kPag).
Connection sizes are 7/8 in (22.2mm) OD copper for 3 ton units.
19 Liebert® Mini-Mate2
™
Site Preparation and Installation
!
Water/Glycol Loop
Emerson recommends installing manual service shutoff valves at the supply and return line to each
unit. This permits routine service and emergency isolation of the unit. Install 1/2" (13mm) diameter
condensing fluid inlet and 1/2" (13mm) diameter condensing fluid outlet.
When the condensing fluid quality is poor, Emerson recommends placing proper filters in the supply
line to extend the service life of the condenser. These filters must be easily replaced or cleaned. The
standard maximum fluid pressure is 150 psig (1034 kPa) or optional 350 psig (2413 kPa) systems. For
applications above this pressure, consult the factory.
The water/glycol-cooled system will operate in conjunction with a cooling tower, city water or
drycooler.
NOTICE
Risk of frozen pipes and corrosion from improper coolant mixture. Can cause equipment and
building damage.
When piping or the Liebert Mini-Mate2 may be exposed to freezing temperatures, charge the
system with the proper percentage of glycol and water for the coldest design ambient.
Automotive antifreeze is unacceptable and must NOT be used in any glycol fluid system. Use
only an HVAC glycol solution only that has been prepared according to industry practices.
Refrigerant (R-407C) Loop
All split systems require two refrigerant lines (an insulated copper suction line and a copper liquid
line) between the evaporator and the condensing unit.
The refrigerant lines can be piped by installing:
• an optional sweat adapter kit and hard piping between the two units
• optional pre-charged line sets (maximum combined length of 45' [13.7m])
• close coupling the units together using the quick connects. (See Figure 17)
WARNING
Risk of explosive discharge from high-pressure refrigerant. Can cause injury or death.
This unit contains fluids and gases under high pressure. Relieve pressure before working with
piping.
All refrigeration piping should be installed with high-temperature brazed joints. Prevailing good
refrigeration practices should be employed for piping supports, leak testing, evacuation, dehydration
and charging of the refrigeration circuits. The refrigeration piping should be isolated from the
building with vibration-isolating supports. To prevent tube damage when sealing openings in walls
and to reduce vibration transmission, use a soft, flexible material to pack around the tubes.
NOTICE
Risk of twisted or kinked piping. Can cause flow restriction or leaks.
Handle the pre-charged lines with care so they do not get kinked or damaged. Use tube
benders and make all bends before making connections to either end. Coil any excess tubing
in a horizontal plane with the slope of the tubing toward the condensing unit.
Liebert® Mini-Mate2
™
20
Field-Fabricated Piping
Evaporator
Evaporator
Condensing
Unit
NOTE
When installing remote condensing units below the
evaporator, the suction gas line should be trapped with
an inverted trap to the height of the evaporator . This
prevents refrigerant migration to the compressors
during off cycles . Maximum recommended vertical
level drop to condensing unit is 15 ft. (4.6m) .
Pitch down 1/2" (13mm) per 10 ft. (3m)
Suction Line Piping
Condensing Unit Above Evaporator
Traps recommended at the base of riser exceeding
5 ft (1.5m) and every 20 feet (6m) of vertical rise.
Suction Line Piping
Condensing Unit
Below Evaporator
Condensing
Unit
Pitch down 1/2" (13mm) per 10 ft. (3m)
See Table 9 for recommended maximum
vertical rise above/fall below evaporator.
All field-fabricated refrigeration piping should use copper pipe with high-temperature brazed joints.
A brazing alloy with a minimum temperature of 1350°F (732°C), such as Sil-Fos. Avoid soft solders
such as 50/50 or 95/5.
1. Use sweat adapter kit matched to the Liebert Mini-Mate2 and outdoor condensing unit
refrigerant connection sizes.
2. Measure pipe runs and calculate pipe size and equivalent feet of suction and liquid lines per
Tables 8 and 12.
3. Use a flow of dry nitrogen through the piping during brazing to prevent formation of copper oxide
scale inside the piping. Copper oxide forms when copper is heated in the presence of air. POE oil
will dissolve these oxides from inside the copper pipes and deposit them throughout the system,
clogging filter driers and affecting other system components. A pure dry nitrogen flow of
3
1-3 ft
/min (0.5-1.5 l/s) inside the pipe during brazing is sufficient to displace the air. Control the
flow using a suitable metering device.
4. Pressurize and leak-test the completed lines at approximately 150 psig (1034kPa) pressure.
5. Evacuate each line twice to 250 microns. Break the vacuum each time with clean, dry nitrogen.
6. Evacuate the lines a third time to 250 microns.
7. See Quick Connect Fittings on page 23 for the proper procedure to connect lines to each unit
of the split system.
8. Add refrigerant (R-407C) to the completed system as calculated per Table 10 for both liquid and
suction line sizes used.
When installing remote condensing units above the evaporator, the suction gas line should be trapped
at the evaporator. This trap will retain refrigerant oil during the Off cycle. When the unit starts, oil in
the trap is carried up the vertical riser and returns to the compressor (see Figure 12).
Figure 12 Refrigerant piping diagram
Site Preparation and Installation
NOTE
When installing remote condensing units below the evaporator, the suction gas line should be
trapped with an inverted trap the height of the evaporator. This prevents refrigerant migration
to the compressor during off cycles.
21 Liebert® Mini-Mate2
™
Site Preparation and Installation
Table 8 Recommended refrigerant line sizes
Equivalent
Length, ft (m)
Suction Liquid Suction Liquid
50 (15.2) 7/8" 3/8" 7/8" 1/2"
100 (30.5) 7/8" 1/2" 1-1/8"
150 (45.7) 7/8" 1/2" 1-1/8"
1. Suction line and liquid line sizing based on < 3 psi pressure drop in each and
horizontal suction line refrigerant velocities >700FPM (3.6m/s).
2. Suction size should be reduced one pipe size for vertical riser sections to
maintain suction line velocity > 1000FPM (5.1m/s) for proper oil return.
2 Ton 3 Ton
2
2
1/2"
1/2"
Table 9 Pipe length and condenser elevation relative to evaporator
Nominal
System Size
Tons
2 150 (45) 40 (12) 15 (4.6)
3 150 (45) 50 (15) 15 (4.6)
Maximum recommended total equivalent pipe length is 150 ft (46m). Suction and liquid lines may require additional specialty
items when vertical lines exceed 20 ft. (6m) and/or condensing unit installation is more than 15 ft. (4.6m) below the evaporator.
Contact Emerson Application Engineering for assistance.
Max. Equiv.
Pipe Length
ft. (m)
Maximum PFH
Level Above
Evaporator, ft. (m)
Maximum PFH
Level Below
Evaporator, ft. (m)
Table 10 Line charges - refrigerant per 100 ft. (30m) of Type L copper tube
Line Size,
O.D., in.
R-407C, lb/100 ft. (kg/30m)
Liquid Line Suction Line
3/8 3.7 (1.7) —
1/2 6.9 (3.1) —
5/8 11.0 (5.0 0.4 (0.2)
3/4 15.7 (7.1) 0.6 (0.3)
7/8 23.0 (10.4) 1.0 (0.4)
1-1/8 — 1.7 (0.7)
1-3/8 — 2.7 (1.1)
Table 11 Refrigerant charge in Liebert pre-charged R-407C line sets
Line Size, in. Length, ft. (m) Charge R-407C, oz (kg)
3/8 liquid
5/8 or 7/8 suction
15 (4.5) 5 (0.14)
30 (9) 10 (0.28)
15 (4.5) 5 (0.14)
30 (9) 10 (0.28)
Table 12 Equivalent lengths for various pipe fittings, ft (m)
Copper Pipe
OD, in.
1/2 0.8 (0.24) 1.3 (0.39) 0.4 (0.12) 2.5 (0.76) 0.26 (0.07) 7.0 (2.13) 4.0 (1.21)
5/8 0.9 (0.27) 1.4 (0.42) 0.5 (0.15) 2.5 (0.76) 0.28 (0.08) 9.5 (2.89) 5.0 (1.52)
3/4 1.0 (0.3) 1.5 (0.45) 0.6 (0.18) 2.5 (0.76) 0.3 (0.09) 12.0 (3.65) 6.5 (1.98)
7/8 1.45 (0.44) 1.8 (0.54) 0.8 (0.24) 3.6 (1.09) 0.36 (0.1) 17.2 (5.24) 9.5 (2.89)
1-1/8 1.85 (0.56) 2.2 (0.67) 1.0 (0.3) 4.6 (1.4) 0.48 (0.14) 22.5 (6.85) 12.0 (3.65)
1-3/8 2.4 (0.73) 2.9 (0.88) 1.3 (0.39) 6.4 (1.95) 0.65 (0.19) 32.0 (9.75) 16.0 (4.87)
1-5/8 2.9 (0.88) 3.5 (1.06) 1.6 (0.48) 7.2 (2.19) 0.72 (0.21) 36.0 (10.97) 19.5 (5.94)
Refrigerant trap = Four times equivalent length of pipe per this table
90 Degree
Elbow Copper
90 Degree
Elbow Cast
45 Degree
Elbow Tee
Gate
Valve
Globe
Valve
Angle
Valve
Liebert® Mini-Mate2
™
22
Site Preparation and Installation
Refrigerant Charge Requirements
Total R-407C refrigerant charge will be required only if units are evacuated during installation or
maintenance. For safe and effective operation, refer to pressures in 5.5.3 - Piping Connections and
Coolant Requirements.
Total Refrigerant = Units and Lines
Table 13 Refrigerant charge
Model #
MM*24E/K — 7 (0.198)
MM*36E/K MM*35E/K 7 (0.198)
MC*24AL_H7 — 134 (3.80)
MC*36AL_H7 MC*35AL_H7 213 (6.04)
MC*26W_H7 — 41 (1.16)
MC*38W_H7 MC*37W_H7 54 (1.54)
PFH027-_L7 — 134 (3.80)
PFH027-_H7 — 213 (6.04)
PFHZ27-_L7 — 213 (6.04)
PFH037-_L7 PFH036-_L7 213 (6.04)
PFH037-_H7 PFH036-_H7 426 (12.08)
PFHZ37-_L7 PFHZ36-_L7 426 (12.08)
Charge R-407C
oz (kg) 60Hz 50Hz
Quick Connect Fittings
NOTE
When hard piping is used, complete all piping and evacuate lines before connecting quick
connects.
Be especially careful when connecting the quick connect fittings. Read through the following steps
before making the connections.
1. Remove protector caps and plugs.
2. Carefully wipe coupling seats and threaded surfaces with a clean cloth.
3. Lubricate the male diaphragm and synthetic rubber seal with refrigerant oil.
4. Thread the coupling halves together by hand to insure that the threads mate properly.
5. Tighten the coupling body hex nut and union nut with the proper size wrench until the coupling
bodies “bottom out” or until a definite resistance is felt.
6. Using a marker or pen, make a line lengthwise from the coupling union nut to the bulkhead.
7. Tighten the nuts an additional quarter-turn; the misalignment of the lines shows how much the
coupling has been tightened. This final quarter-turn is necessary to insure that the joint will not
leak. Refer to Table 14 for torque requirements.
Table 14 Connection sizes and torque
Size OD Cu Model Tons Coupling Size Torque Ib-ft.
3/8 2 and 3 #6 10-12
5/8 2 and 3 #11 35-45
23 Liebert® Mini-Mate2
™
Site Preparation and Installation
1"
(25.4mm)
11"
(279mm)
20" (508mm)
15"
(381mm)
18"
(457mm)
18"
(457mm)
19-7/8"
(505mm)
Duct
Flange
3/4"
(19mm)
1"
(25.4mm)
Filter Box (optional)
24"
(610mm)
Cabinet
Dimension
18" (457mm)
18"
(457mm)
18" (457mm)
Cabinet Dimension
same as above
Hanging
Bracket
Shaded area
indicates a recommended
clearance of 30" (762mm)
for access and filter removal
Shaded area indicates a
recommended clearance
of 30" (762mm) for access
and filter removal
7/8" (22mm) holes
for module rigging
(typ. 2 each end).
Note: Unit is spaced evenly in
reference to threaded rod centers
1-7/16"
(37mm)
1-7/16"
(37mm)
14"
(356mm)
Removable
Access
Panels
27-13/16"
(706mm)
Threaded Rod
Centers
Cabinet Outline
Removable panel on
side of plenum.
Minimum clearance
30" (762mm) for filter
access and removal
Air Discharge out
sides of plenum
Air Discharge out
sides of plenum
Cover Plate
Supplied With
Plenum
Air Inlet through
grille in center of plenum
24"
(610mm)
Overall
Dimension
Optional Air Distribution Plenum
All piping and electrical field connections are the same
30"
(762mm)
Cabinet
Dimension
DPN000193
Rev. 3
6" (152mm)
48"
(1219mm)
Overall
Dimension
3-7/8"
(98mm)
14"
(356mm)
14"
(356mm)
Customer-Supplied
Threaded Rods for
Module Suport from
Ceiling (Typ. 4)
11-1/8"
(283mm)
5"
(127mm)
3-1/4"
(83mm)
Overall
Dimension
Dimension
55-13/16"
(1418mm)
Rod
Centers
57-13/16"
(1468mm)
54"
(1372mm)
Optional discharge air
duct flange supplied when
optional filter box is ordered
10-7/8"
(276mm)
11-5/8"
(295mm)
Cabinet
Threaded
Module Dimensions
Figure 13 Dimensions, evaporator and chilled water units with direct drive blower
Table 15 Net weights—evaporator and chilled water units
Model #
Weight, lb (kg)60Hz 50Hz
MM*24E — 225 (102)
MM*24K — 245 (111)
MM*36E MM*35E 225 (102)
MM*36K MM*35K 245 (111)
MM*40C MM*39C 230 (104)
Source: DPN000193, Rev. 3
Liebert® Mini-Mate2
™
24
Figure 14 Dimensions, evaporator units with optional belt drive blower assembly
DPN000194
Rev. 3
19" (483mm)
Blower Box
Dimension
4-29/32" (125mm)
Cabinet to Cabinet
4-29/32" (125mm)
Threaded Rod
To Threaded Rod
57-13/16" (1468mm)
Overall Dimension
55-13/16" (1418mm)
Threaded Rod Centers
54" (1372mm)
Cabinet Dimension
High Static
Blower
Module
Evap
Unit
30" (762mm)
Blower Box
Dimension
5-7/8"
(149mm)
29-7/8" (759mm)
Threaded
Rod Centers
3-7/32"
(82mm)
Base to
Base
14"
(356mm)
Outlet
Dimension
6-7/8" (175mm)
6-5/16" (160mm) Outlet
9-3/4" Outlet
(248mm)
16-13/16" (427mm)
Threaded Rod Centers
24" (610mm)
Cabinet
Dimension
30" (762mm)
Cabinet
Dimension
18 "
(457mm)
Outlet
Dimension
Site Preparation and Installation
Table 16 Net weight, high static blower module
Net Weight
Unit
High Static
Blower Module
Source: DPN000194, Rev. 3
lb (kg)
85 (39)
25 Liebert® Mini-Mate2
™
Figure 15 Evaporator and chilled water unit piping data
Entrance for Customer
High-Voltage Connections
Entrance for Customer HighVoltage Connections with (SPPK)
Single Point Power Kit
Evaporator Air
Inlet on Ducted
Version
Filter Clog
Switch Option
Connection Point
Entrance for Customer LowVolt Connections
7/8" (22.2mm) Diameter
Entrance For Low-Voltage Connection
to Condensing Unit (if applicable)
Hot Water Reheat 5/8" (15.9mm) OD Cu
or Free Cooling Outlet 7/8" (22.2mm) OD Cu
Extends 3-1/2" (88.9mm) Beyond Panel Exterior
Hot Water Reheat 5/8" (15.9mm) OD Cu
or Free Cooling Inlet 7/8" (22.2mm) OD Cu
Extends 3-1/2" (88.9mm) Beyond Panel Exterior
Evaporator Air
Outlet on Ducted Version
Optional 1/4" O. D.
Compression Fitting.
Use Copper Lines for
Humidifer Supply Line
NOTE: Route supply line to
Clear hanging rods
7/8" Dia. (22.2mm)
Electrical Entrance for
Condensate Pump
Connection
Suction Refrigerant Line
Quick Connect Female Coupling
with Access Valve
Evaporator Air Outlet
For Plenum Version
Liquid Refrigerant Line
Quick Connect Female Coupling
with Access Valve
Power Supply from
Electric Service Power
Block in Fan/Coil Module
Fan/Coil
Unit
Fan/Coil
Unit
Air Outlet Duct
Drain Line
(Field-Supplied)
Drain Line
(Field-Supplied)
Condensate Pump
3/4" Hose Barb
Supplied on
Pump Tank
3/4" Hose Barb Supplied on
Pump Tank
Flexible Rubber Tubing
Flexible Rubber Tubing
3/4" FPT
Customer Connection
Field-Supplied
Rigid Piping
(Support as Required)
Field-Supplied
Rigid Piping
(Support as Required)
Condensate Drain
Condensate Drain
CONDENSATE PUMP
(Field-installed)
On Unit with Air Outlet Ductwork
CONDENSATE PUMP
(Field-installed)
On Unit with Air Distribution Plenum
Note:
3/4" (19.1mm) Flexible Rubber Tubing Assembly
(Supplied with Pump Kit) must be installed on pump
end of rigid piping; support as required.
Condensate
Pump Support
Brace
3/4" FPT
Customer
Connection
Power Supply
from Electric
Service Power
Block in
Fan/Coil
Module
Evaporator Air Inlet
For Plenum Version
BACK OF UNIT
Chilled Water Return Line(OUT)
7/8" (22.2mm) OD Cu
Extends 3-1/2" (88.9mm) beyond panel exterior
Single Point Power Kit
(SPPK) Harness Connection
from Condensing Unit
Chilled Water Supply Line(IN)
7/8" (22.2mm) OD Cu
Extends 3-1/2" (88.9mm) beyond panel exterior
3/4" NPT Female
Condensate Drain Connection
Drain is trapped internally and
Must Not betrapped outside
the module
FRONT
OF UNIT
DPN00192
Rev. 1
Liebert® Mini-Mate2
™
26
Site Preparation and Installation
5.5.4 Condensate Pump Kit Installation—All Units
!
!
WARNING
Risk of electric shock. Can cause injury or death.
Open all local and remote electric power disconnect switches before making electrical wiring
connections.
1. Refer to detail instructions and drawings supplied with the pump.
2. Disconnect all power to the unit.
3. Remove access panels.
NOTE
Remove any shipping bands from float switch in evaporator pan
4. Use mounting brackets if pump is not attached to ductwork. Pump inlet must be at least 1/2 in.
(12.7mm) below evaporator drain. Mount the pump to unit exterior as shown in Figure 15.
5. Connect 3/4 in. flexible rubber tubing with hose clamp (both supplied with pump kit) to 3/4 in.
hose barb fitting on pump.
6. Connect evaporator drain to 3/4 in. NPT-Female hose assembly on pump inlet using 3/4 in. hard
pipe with no trap in the line. Provide at least 1 in. (25.4mm) clearance between the access panel
and the drain line. Support piping as required.
7. Connect a drain line to the pump discharge 3/8 in. O.D. Cu (compression fitting provided).
8. Connect electric leads L1 and L2 to the line voltage terminal block in the cooling unit. Connect the
ground lead to the lug near the terminal block.
9. Connect wires from the Auxiliary Pump contacts to terminals TB1-8 and TB1-9 to shut down unit
at the occurrence of a high water condition in the pump.
10. Reinstall the access panels.
11. Reconnect power to the unit.
12. Run the unit to make sure the pump works properly. Operate the pump and check the drain line
and discharge line for leaks. Correct as needed.
Site Preparation and Installation
NOTE
3/4" flexible rubber tubing assembly (supplied with pump kit) must be installed on pump end
of rigid piping (field-provided and supported as required).
5.5.5 Electrical Connections
Each unit is shipped from the factory with internal wiring completed. Refer to electrical schematic
when making connections. Electrical connections to be made at the installation site are:
WARNING
Arc flash and electric shock hazard. Open all local and remote electric power disconnect
switches and wear protective equipment per NFPA 70E before working within the electric
control enclosure. Failure to comply can cause injury or death.
Unit contains hazardous voltage/electric power.
Line side of factory disconnect remains energized when factory disconnect is Off.
• Power supply to each ceiling unit.
• Control wiring between the evaporator unit and the condensing unit, if applicable.
• Control wiring between the control panel (wall box) and the evaporator unit control board.
Entrance locations for these connections are noted on drawing in each installation section.
27 Liebert® Mini-Mate2
™
Site Preparation and Installation
!
Power Connections
All power and control wiring and ground connections must be in accordance with the National
Electrical Code and local codes. Refer to electrical schematic on unit for electrical requirements.
WARNING
Risk of loose electrical wiring connections. Can cause over heating of wire, smoke, and fire
resulting in building and equipment damage, serious injury or death.
Use copper wiring only. Make sure that all connections are tight.
Voltage supplied must agree with the voltage specified on the unit name plate. If a field-supplied
disconnect switch is required, it may be bolted to the ceiling unit but not to any of the removable
panels. This would interfere with access to the unit. Make sure that no refrigerant lines are
punctured when mounting the disconnect switch.
Route the electrical service conduit through the hole provided in the cabinet and terminate it at the
electric box. Make connections at the factory terminal block or disconnect switch, L1, L2, (L3).
Connect earth ground to lug provided. For 208VAC applications, the low voltage transformer tap
must be changed. Refer to the electrical schematic.
An optional single point power kit is available for units that are installed close-coupled. This kit
should be mounted inside the evaporator before installing the unit in the ceiling (See Figure 17).
Specific installation instructions are included with the single point power kit.
Control Connections
A field-supplied 4-wire control connection (24 VAC) is required between the evaporator and the
condensing unit. Control wiring must be installed in accordance with the National Electrical Code
(NEC) Class 2 circuit. Glycol cooled units also require a two-wire control connection to the drycooler
and pump. A Class 1 circuit is required for Water/Glycol units.
Control wiring between the evaporator and the condensing unit must not allow a voltage drop in the
line of more than 1 volt (16 gauge minimum for 75 feet). Do not connect additional electrical devices to
the control circuit. The circuit breaker, contained in the transformer housing, is sized only for the
factory-supplied control system.
Additional control wiring will be required if your system includes other optional monitoring and
control devices.
NOTE
Refer to specifications for full load amp. and wire size amp. ratings.
Liebert® Mini-Mate2
™
28
Figure 16 Evaporator and chilled water unit electrical connections
Remote Control Panel Connection to TB3-1,2,3,4 connected with field-supplied
thermostat wire (22ga., shielded/ jacketed: available from Emerson or others).
Unit Control Board terminals marked GND, +5V, T-, T+ must be connected to
corresponding terminals on Remote Control Wall Box.
Common alarm connection. Field-supplied 24V
Class 2 wiring to common alarm conn TB1-6 and TB1-7
Entrance for customer
low-voltage connections.
Remote Humidifier Contact
Field-Supplied 24V class 2
wiring to terminals 11 & 12,
located in field wire
compartment
Site monitoring connection. Terminals
TB4-1(+) TB4-2(-) are for connection
of a 2 wire. twisted pair, communication
cable (available from Emerson or others)
to optional Liebert SiteScan
Customer remote alarm connection
field-supplied 24V. Class 2 wiring
to conn TB1-1, TB1-2 & TB1-3
Remote unit shutdown. Replace existing
jumper between Terminals TB1-4 & TB1-5
with normally closed switch having a
minimum 75VA rating. Use field-supplied
24V Class 1 wire.
Optional condensate
pump aux float switch
connection to term
TB1-8 & TB1-9
Field-supplied unit disconnect
switch when factory unit disconnect
switch is not supplied
Factory-installed
disconnect switch
Electric service not by Emerson
Entrance for Customer
High-Voltage Connections
Entrance for Customer
Low-Voltage Connections
Drycooler/Circulating pump
control circuit TB70-71.
Optional w/Econ-O-Cycle
models. Use field-supplied
24V Class 2 wire.
Field-supplied,
field-wired thermostat
wire to remote
wall box
Field-supplied 24V (NEC Class 2 wiring) to
condensing module. (if applicable)
NOTES:
1.Refer to specification sheet for full load amp and wire size amp ratings.
2.Control voltage wiring must be a minimum of 16ga. (1.3mm) for up to
75' (23m) or not to exceed 1 volt drop in control line
DPN000195
Rev. 2
Electrical entrance for
optional condensate
pump
High-Voltage Power Connections. Electric
service connection terminals
Earth ground connection
Connection terminal for fieldsupplied earth grounding wire
Heat rejection connection. Field-supplied
24V NEC class 2 wiring. See note 2.
For remote air cooled units from
terminals TB2-1, 2, 3 & 4 in the
Fan/Coil module to wires 1, 2, 3 & 4
in the condensing module
1. 24V GND
2. 24V Supply
3. High Pressure Alarm (OPT)
4. Hot Gas Bypass Connection
Site Preparation and Installation
29 Liebert® Mini-Mate2
™
Figure 17 Close-coupled installation
Line Voltage Electrical Power
Supply Entrance (Electric service
not by Emerson)
Site Preparation and Installation
Close-Coupled
Centrifugal Air-Cooled
or Water/Glycol
Condenser
Condenser
Evaporator
Evaporator Unit Electric Box
Single-Point Power Kit Option
Factory-supplied, field-installed
and field-wired
DPN000196
Rev. 0
5.6 Indoor Air-Cooled Centrifugal Fan Condensing Unit Installation
5.6.1 Location Considerations
The centrifugal fan air-cooled condensing unit may be located above the dropped ceiling or any remote
indoor area. If noise is of concern, the condensing unit should be located away from personnel. Normal
operating sound may be objectionable if the condensing unit is placed near quiet work areas. Refer to
Table 9 for maximum refrigerant line lengths.
To mount the unit in the ceiling, refer to 5.5 - Installing the Ceiling Units.
5.6.2 Electrical Connections
Refer to 5.5.5 - Electrical Connections for general wiring requirement and cautions. Refer to the
unit’s electrical schematic when making connections. Refer to the unit’s specifications for full load
amp and wire size amp ratings.
Liebert® Mini-Mate2
™
30
5.6.3 Piping Connections
Details for refrigerant (R-407C) loop piping are in 5.5.3 - Piping Connections and Coolant
Requirements.
5.6.4 Ducting
The total external static pressure for the inlet and outlet ducts, including grille, must not exceed 0.5
inches of water.
General Considerations
Use flexible ductwork or nonflammable cloth collars to attach ductwork to the unit and to control
vibration transmission to the building. Attach the ductwork to the unit using the flanges provided.
Locate the unit and ductwork so that the discharge air does not short circuit to the return air inlet.
Ductwork that runs through a conditioned space or is exposed to areas where condensation may occur
must be insulated. Ductwork should be suspended using flexible hangers. Ductwork should not be
fastened directly to the building structure.
For multiple unit installations, space the units so that the hot condensing unit exhaust air is not
directed toward the air inlet of an adjacent unit.
Considerations for Specific Applications
In applications where the ceiling plenum is used as the heat rejection domain, the discharge
air must be directed away from the condensing unit air inlet and a screen must be added to the end of
the discharge duct to protect service personnel. Locate the air discharge a minimum of 4 feet from an
adjacent wall. Failure to do so may result in reduced air flow and poor system performance.
Site Preparation and Installation
If the condensing unit draws air from the outside of the building, rain hoods must be
installed. Hood intake dimensions should be the same as the condensing unit duct dimensions. In
addition, install a triple layer bird screen over rain hood openings to eliminate the possibility of
insects, birds, water, or debris entering the unit.Avoid directing the hot exhaust air toward adjacent
doors or windows.
Table 17 Indoor condensing unit airflow, CFM at 0.5 iwg esp
2 Ton 3 Ton
1000 1430
31 Liebert® Mini-Mate2
™
Site Preparation and Installation
50-1/4" (1276mm)
Overall Dimension
46-1/2" (1181mm)
Cabinet Dimension
48- 1/4" (1225mm)
Threaded Rod Centers
21-1/2 " (546mm)
Cabinet Dimension
19-1/2" (495mm)
Threaded Rod
Centers
Rods
for Module Support
from Ceiling (typ. 4)
C
D
Air Outlet
Duct Connection
B
A
Air Ou
tlet
Duct Dimension
Duct Flange
2-1/4"
(57mm)
1"
(25.4mm)
20-7/16"
(519mm)
Coil Inlet
Duct Conn.
Minimum Clearance 33" (838mm)
This End for Component Access
and Removal
20-3/4"
(527mm)
1/2" (13mm)
7/8" (22.2mm) Dia.
Electrical Entrance
for Low Voltage
Connection.
Suction Line
Liquid Line
Male Quick
Connect
Male
Quick Connect
Note:
Unit is evenly spaced in
reference to threaded rod centers.
DIMENSIONAL DATA
Blower Motor Service Access
Panel on Bottom of Unit
Minimum Clearance 33" (838mm)
for Component Access and Removal.
30-1/8"
(765
mm)
Coil Inlet
Duct Connection
Integral
Hanging
Bracket
Holes for Module
Rigging (typ. 2 each end)
22-1/2"
(572mm)
Cabinet
Dimension
7/8"
(22.2mm) Dia.
Electrical Entrance
for Line Voltage
Connection.
Customer Supplied
Threaded
22-3/4" (578mm)
Overall Dimension
DPN000206
Rev. 1
Figure 18 Indoor air-cooled centrifugal condenser dimensions and pipe connections
Table 18 Centrifugal condenser dimensions, weights
ModelABCD
MC*24A
MC*35A
MC*36A
Source: DPN000206, Rev. 1
1-7/16 (37) 11-7/16 (290) 1/2 (13) 20-7/16 (519)
Net Weight
lb (kg)
230 (104)
240 (109)
Liebert® Mini-Mate2
™
32
Figure 19 Centrifugal condenser electrical connections
Field-supplied unit disconnect switch
when factory unit disconnect is not
provided in unit
Single- or three-phase
electric service not
by Emerson
Field-supplied 24V NEC
Class 2 wiring to fan/coil
unit
Line voltage electric power
supply conduit entrance
Factory-installed
disconnect switch
Factory-wired
to components on
electric panel
Single- or three-phase
electric service
not by Liebert
Connection terminal
for field-supplied
earth grounding wire
Low voltage
electric power
supply entrance
DPN000207
Rev. 2
Heat rejection connection
Field-supplied 24V NEC Class 2
wiring. See note 2.
Wire connections from
evaporator mod:
1. 24V GRD
2. 24V Supply
3. High-Pressure Alarm (OPT)
4. Hot Gas Bypass Connection
NOTES:
1. Refer to specification sheet for full load amp and
wire size amp. ratings.
2.Control voltage wiring must be a minimum of 16GA (1.3mm)
for up to 75' (23m) or not to exceed 1 volt drop in control line.
Site Preparation and Installation
33 Liebert® Mini-Mate2
™
Site Preparation and Installation
5.7 Outdoor Air Cooled Condensing Unit Installation
5.7.1 Location Considerations
NOTE
Follow all national and local building, electrical and plumbing codes.
To ensure a satisfactory air supply, locate air cooled propeller fan condensing units in an environment
providing clear air, away from loose dirt and foreign matter that may clog the coil. Condensing units
must not be located in the vicinity of steam, hot air, or fume exhausts, or closer than 18 inches from a
wall, obstruction, or adjacent unit. Avoid areas where heavy snow will accumulate at air inlet and
discharge locations.
The condensing unit should be located for maximum security and maintenance accessibility. Avoid
ground-level sites with public access. Refer to Table 9 for maximum refrigerant line lengths.
Install a solid base, capable of supporting the weight of the condensing unit. The base should be at
least 2 inches higher than the surrounding grade and 2 inches larger than the dimensions of the
condensing unit base. For snowy areas, a base of sufficient height to clear snow accumulation must be
installed.
Figure 20 Cabinet and floor planning dimensional data, outdoor condensing unit
Fan Rotation
CCW
(left side)
Left Air Intake
Shaded area
indicates a minimum
clearance of 18" (457mm)
for proper air flow
Removable (right) panel
for access to
A
refrigeration component
B
C
C
Removable panel for access
to high-voltage and low-voltage
connections and refrigeration
components
Right Air Discharge
Shaded area
indicates a minimum
clearance of 18" (457mm)
for proper air flow.
Shaded area
indicates a recommended
clearance of 24" (610mm)
for component access and
removal.
DPN000130
Rev. 1
Liebert® Mini-Mate2
™
34
Table 19 Dimensions and net weights—air-cooled outdoor condensing units
Model Numbers Dimensions, inches (mm) Module Net
PFH027A-L — 40 (1016) 23-1/2 (597) 18 (457) 200 (91)
PFH027A-H —
PFH037A-L PFH036A-L
PFH037A-H PFH036A-H
PFHZ37A-L PFHZ36A-L
Source: DPN000130, Rev. 1
5.7.2 Piping Connections
Details for Refrigerant (R-407C) Loop piping are in 5.5.3 - Piping Connections and Coolant
Requirements.
5.7.3 Electrical Connections
Refer 5.5.5 - Electrical Connections for general wiring requirements and cautions. Refer to
electrical schematic when making connections.
Power Connections
Site Preparation and Installation
Weight
lb (kg)60Hz 50Hz A B C
48 (1219) 31 (787) 18 (457) 241 (109)PFHZ27A-L —
53 (1343) 36-1/4 (918) 18 (457) 351 (159)
The outdoor condensing unit requires its own power source and earth ground, with a disconnect
switch (field supplied) to isolate the unit for maintenance. A transformer is available for 277 VAC,
single phase, applications (2- and 3-ton).
Control Connections
Field-supplied control wires must be connected between the evaporator and the condensing unit. (See
Figure 16 and the electrical schematic on the units for more details.) Four wires are required
between the evaporator and condensing unit.
35 Liebert® Mini-Mate2
™
Figure 21 General arrangement (air- cooled condensing unit)
DPN000191
Rev. 2
*
*
Condenser
Coil
High Pressure
Switch
Scroll
Compressor
Hot Gas Bypass
Solenoid Valve
Hot Gas Bypass
Control Valve
3/8" SAE 45° Male Flare
(MCD) or Atmospheric (PFH)
Pressure Relief Valve
Check
Valve
Sight Glass
Lee - Temp
Receiver
Liquid Line
Solenoid Valve
Liquid Injection
Valve Bulb
Suction Line Male Quick
Connect Coupling
3 - Way Head
Pressure
Relief Valve
Liquid Line Male Quick
Connect Coupling
Liquid Line Female Quick
Connect Coupling
Expansion Valve
Liquid Injection
Valve
Service Access
Ports
Evaporator Coil
Suction Line Female Quick
Connect Coupling
External Equalizer
Sensing Bulb
Receiver
Heater
Pressure
Limiting
Switch
Pressure Balancing
Valve
* Use Liebert sweat adapter kit with field
hard piping or use Liebert pre-charged
line set. Close-coupling option
available with MCD.
Field Piping
Factory Piping
Site Preparation and Installation
5.8 Water and Glycol Cooled Condensing Unit
NOTE
Follow all national and local building, electrical and plumbing codes.
5.8.1 Location Considerations
The centrifugal fan air cooled condensing unit may be located above the dropped ceiling or any remote
indoor area. If noise is of concern, the condensing unit should be located away from personnel. Normal
operating sound may be objectionable if the condensing unit is placed near quiet work areas. Refer to
Table 9 for maximum refrigerant line lengths.
To mount the unit in the ceiling, refer to 5.5 - Installing the Ceiling Units.
Liebert® Mini-Mate2
™
36
Site Preparation and Installation
Figure 22 Cabinet dimensions and piping data, water/glycol indoor condensing module
3-7/8" (98mm)
8-7/16"
(214mm)
Customer-Supplied
Threaded Rods for
Module Support
from Ceiling (typ. 4)
Holes for Module
Rigging (typ. 2 each end)
7/8" (22.2mm) OD CU
Water/Glycol Outlet Connection
Extends 3-1/2" (88.9mm) beyond
panel exterior
8-7/8" (225mm)
50-1/4" (1276mm)
Overall Dimension
48-1/4" (1225mm)
Threaded Rod Centers
46-1/2" (1181mm)
Outlet
Inlet
Integral
Hanging
Bracket
7/8" (22.2mm) OD CU
Water/Glycol Inlet Connection
Extends 3-1/2" (88.9mm) beyond
panel exterior
Cabinet Dimension
Note:
Unit is spaced evenly in
reference to threaded rod centers
DIMENSIONAL DATA
7/8" (22mm) Dia.
Electrical Entrance
for High Voltage
Connection
14" (356mm)
Overall Cabinet
Dimension
12" (305mm)
Threaded Rod
Centers
20-3/4"
(527mm)
22-1/2"
(572mm)
Minimum Clearance
33" (838mm) this side
for component access
and removal.
Cabinet
Dimension
Suction Line
Male Quick
Connect
Liquid Line
Male Quick
Connect
7/8" (22mm) Dia.
Electrical Entrance
for Low Voltage
Connection
PIPING CONNECTIONS
Table 20 Net weight, indoor water/glycol-cooled condensing unit
Model #
MC*26W — 175 (79)
MC*38W MC*37W 220 (100)
Source: DPN000208, Rev. 4
Weight
lb (kg)60Hz 50Hz
DPN000208
Rev. 4
37 Liebert® Mini-Mate2
™
5.8.2 Electrical Connections
Refer to 5.5.5 - Electrical Connections for general wiring requirements and cautions. Refer to
electrical schematic when making connections. Refer to specifications for full load amp. and wire size
amp. ratings.
Control Connections
A 4-wire control connection is required from the evaporator unit to the condensing unit. Glycol cooled
units also require a two-wire control connection to the drycooler and pump package.
5.8.3 Piping Connections
Details for refrigerant (R-407C) loop piping are in 5.5.3 - Piping Connections and Coolant
Requirements.
Water/Glycol Piping Considerations
Manual service shutoff valves should be installed at the supply and return line to each unit. This
enables routine service and/or emergency isolation of the unit. When the condensing unit fluid quality
is poor, filters that can be easily serviced should be placed in the supply line. These filters extend the
service life of the condensing unit.
Condensing Unit Fluid Requirements
The maximum fluid pressure is 150 PSI standard pressure and 350 PSI for high pressure units (refer
to unit nameplate and model number description page at beginning of this manual). The water cooled
system will operate in conjunction with either a cooling tower or city water. Glycol cooled systems will
operate in conjunction with a cooling tower, city water, or drycooler.
Site Preparation and Installation
Automotive anti-freeze must not be used in glycol systems. Prepare glycol solution using customary
practices.
Regulating Valve
Water/Glycol cooled units include a coolant flow regulating valve which is factory adjusted and should
not need field adjustment.
Standard pressure and high pressure valves are adjusted differently. Contact Emerson Network
®
Power
Liebert Services before making any adjustments.
Liebert® Mini-Mate2
™
38
Figure 23 General arrangement, water/glycol split systems
*
*
DPN000190
REV 1
Tube in Tube
Condenser
Tube in Tube
Condenser
High Pressure
Scroll Switch
Scroll
Compressor
Suction Line Male Quick
Connect Coupling
Liquid Line
Male Quick
Connect
Coupling
Water/Glycol
Return Line
Water/Glycol
Supply Line
Fluid Supply
To Unit
Fluid Supply
To Unit
Shutoff **
Valves
Hose Bibs **
2 - Way Water
Regulating Valve
Fluid
Return
From Unit
Fluid Return
From Unit
3 - Way Water
Regulating Valve
(Optional)
Suction Line Female Quick
Connect Coupling
Liquid Line
Female Quick
Connect
Coupling
Sensing Bulb
Service Access
Ports
Filter
Drier
Evaporator Coil
Expansion
Valve
FIELD PIPING
FACTORY PIPING
* Use Liebert sweat adapter kit with field
hard piping or use Liebert pre-charged line
set. Close-coupling option available with
MCD.
** Components are not supplied by Liebert
but are recommended for proper circuit
operation and maintenance.
External Equalizer
Hot Gas
Bypass
Solenoid
Valve
Hot Gas Bypass
Control Valve
Liquid Injection
Valve Bulb
Liquid Injection
Valve
Site Preparation and Installation
39 Liebert® Mini-Mate2
™
5.9 Optional Equipment Piping
r
5.9.1 Free-Cooling Coil
The free-cooling coil is a secondary coil located downstream of the DX coil. The free-coiling coil does
not operate at the same time as the DX coil. A temperature sensor is factory-mounted to the freecooling piping. If the water temperature is less than the set temperature (usually 45°F [7.2°C]), the 3way valve opens to allow chilled water flow to the free-cooling coil and the compressor is locked off. If
the water temperature is above the set temperature, the 3-way valve closes (bypasses) and enables
the compressor. To keep deposits from building up in the free-cooling coil, an adjustable timer is
factory-set to flush every 400 minutes.
NOTE
If the free-cooling coil is piped to an open water tower, a CU/NI (copper-nickel) type coil must
be ordered to prevent corrosion of the copper tubes; or a heat exchanger must separate the tower
water from the free-cooling loop.
On water-cooled systems, the free-cooling coil outlet can be field piped to the condensing unit inlet,
provided a 3-way regulating valve has been installed within the water/glycol condensing unit (see
Figure 24).
Figure 24 Optional free-cooling coil (3-way valve) on water/glycol units
Bleed Valve
Site Preparation and Installation
Fluid
Return
From Unit
Shutoff*
Valves
NOTE: RECOMMENDED PIPING FOR UNITS
WITH FREE-COOLING COIL OPTION
AND WATER/GLYCOL CONDENSER.
Fluid
Supply
To Unit
Hose*
Bibs
Free-Cooling
Control
Valve
Temperature
Stat
Free-Cooling
Coil
Shutoff*
Valves
* Components are not supplied by Emerson
but are recommended for proper circuit
operation and maintenance.
Hose*
Bibs
Fluid
Return
From
Unit
Fluid
Supply
To Unit
FIELD PIPING
FACTORY PIPING
Tube in
Tube
Condense
3-Way Water
Regulating
Valve
(Optional)
DPN000219
Rev. 3
Liebert® Mini-Mate2
™
40
5.9.2 Hot Water Reheat Coil
Shutoff
Valves *
Hose
Bibs *
Bleed Valve
Hot Water
Reheat
Control
Valve
Water
Return
From Unit
Water
Supply
To Unit
Y-Strainer
Hot Water
Reheat
Coil
DPN000197
Rev. 2
* Components are not supplied
by Liebert but are recommended
for proper circuit operation and
maintenance.
FIELD PIPING
FACTORY PIPING
NOTE: Hot water reheat only available
on chilled water units.
Building hot water can be piped to a factory-installed hot water reheat coil, located downstream of the
cooling coil. A factory-installed solenoid valve opens upon a call for reheat.
Figure 25 Optional hot water reheat (two-way valve)
Site Preparation and Installation
41 Liebert® Mini-Mate2
™
5.10 Checklist for Completed Installation
___ 1. Proper clearance for service access have been maintained around the equipment.
___ 2. Equipment is level and mounting fasteners are tight.
___ 3. Piping completed to refrigerant or coolant loop (if required). Refrigerant charge added (if
required).
___ 4. Condensate pump installed (if required).
___ 5. Drain line(s) connected/and checked for leaks.
___ 6. Water supply line connected to humidifier (if required).
___ 7. All piping connections are tight.
___ 8. Field provided pan with drain installed under all ducted cooling units and water/glycol
condensing units.
___ 9. Filter box installed on ducted units.
___ 10. Ducting completed or optional plenum installed.
___ 11. Filter(s) installed in return air duct.
___ 12. Line voltage to power wiring matches equipment nameplate.
___ 13. Power wiring connections completed between disconnect switch, evaporator and condensing
unit, including earth ground.
___ 14. Power line circuit breakers or fuses have proper ratings for equipment installed.
___ 15. Control wiring connections completed to evaporator and condensing unit (if required,
including wiring to wall-mounted control panel and optional controls).
___ 16. Control panel DIP switches set based on customer requirements.
___ 17. All wiring connections are tight.
___ 18. Foreign materials have been removed from in and around all equipment installed (shipping
materials, construction materials, tools, etc.)
___ 19. Fans and blowers rotate freely without unusual noise.
___ 20. Inspect all piping connections for leaks during initial operations. Correct as needed.
___ 21. Drain pan is installed under ducted cooling unit and ceiling mounted condensing unit.
___ 22. Rubber band is removed from evaporator condensate pan float switch.
Site Preparation and Installation
Liebert® Mini-Mate2
™
42
6.0 MICROPROCESSOR CONTROL
Up Arrow
Escape Key
On/Off Key
Menu Key
Alarm Silence/
Help Key
Enter Key
Down Arrow
Fan Speed Key
The Microprocessor Control for the Liebert Mini-Mate2 features an easy to-use, menu-driven liquid
crystal display. The menus, control features and circuit board details are described in this section.
Detailed information concerning controls (7.0 - System Performance Microprocessor Controls)
and alarms (8.0 - Alarms) are provided.
6.1 Feature Overview
To turn the unit ON, press the ON/OFF (I/O) key after power is applied. To turn the unit OFF, press
the ON/OFF (I/O) key before power is disconnected.
The following control keys may be used to move through the menus, as prompted on the LCD:
• On/Off (I/O): Turns unit on or off (top far left).
• Menu: Enables user to access the program menu to change control parameters, alarms, setback
schedule, etc. (top near left).
• Up Arrow: Increases the value of displayed parameter while in a set mode (setpoints, time, etc.)
(Arrow-top near right).
• Fan Speed (HI/LO): Changes the fan speed between high and low fan speed on direct-drive blower
models; not available on high-static belt-driven motor (bottom far left, when present).
• Escape (ESC): Allows user to move back to a previous menu (top far right).
• Alarm Silence/? (Help): If an alarm is present, pressing this key will silence he alarm. If this key
is pressed when no alarms are present, help text will appear (bottom near left).
• Down Arrow: Decreases the value of displayed parameter while in a set mode (bottom near right).
• Enter (ENTER): After setting a control point, press Enter to store the information in the
microprocessor (bottom far right).
Figure 26 Control key locations—all-mounted display box
Microprocessor Control
Active alarms appear on the LCD and sound an audible beeper. To silence an alarm, press the
Alarm Silence/Help key as prompted on the display.
Setpoints, DIP switch settings and other selections were made during factory testing of your unit and
are based upon typical operating experience. (Other default selections were made according to options
included with your unit). MAKE ADJUSTMENTS TO THE FACTORY DEFAULT SELECTIONS
ONLY IF THEY DO NOT MEET YOUR SPECIFICATIONS.
Allowable ranges are displayed by pressing the help key. A password will be required (if enabled) to
change setpoints, time delays, etc.
The display normally shown includes the present room temperature, humidity, active status
functions (cooling, heating, dehumidifying, humidifying), normal fan speed/low fan speed and active
alarms. The Status Display may also be selected from the Main Menu.
43 Liebert® Mini-Mate2
™
6.2 Main Menu <Menu>
Press the MENU key to display the Main Menu. The Menu selections (in the following order) include:
SETPOINTS CALIBRATE SENSORS
STATUS ALARM ENABLE
ACTIVE ALARMS ALARM TIME DELAY
TIME COMMON ALARM ENABLE
DATE CUSTOM ALARMS
SETBACK CUSTOM TEXT
SETUP OPERATION DIAGNOSTICS
SETPOINT PASSWORD END OF MENU
SETUP PASSWORD
Use the Up/Down arrow to scroll through the selections. When ready to select a particular function
press Enter.
6.3 Setpoints
Setpoints and system setup parameters are kept in nonvolatile memory. Selecting SETPOINTS from
the Main Menu will display the following selections:
• TEMPERATURE SETPOINT
• TEMPERATURE SENSITIVITY
• HUMIDITY SETPOINT
• HUMIDITY SENSITIVITY
• HIGH TEMPERATURE ALARM
• LOW TEMPERATURE ALARM
• HIGH HUMIDITY ALARM
• LOW HUMIDITY ALARM
Microprocessor Control
Scroll through this submenu by using the Up/Down arrow, then press Enter to select a particular
function. To change a particular value, press Enter and use the Up/Down arrows to change the value.
When the value has been changed press Enter to store the value. For example to change the
temperature setpoint from the main status display.
1. Press the Menu key to display the main menu.
2. Scroll to “SETPOINTS” using the Up/Down arrow key. Press the Enter key.
3. Scroll to “TEMP SETPOINT” using the Up/Down arrow key. Press the Enter key.
4. Use the Up/Down arrow to change the value. Press the Enter key.
Table 21 View default setpoints and allowable ranges
Setpoint Default Range
Temperature Setpoint 72°F 40-90°F (5-32°C)
Temperature Sensitivity 2.0°F 1-9.9°F (0.6-5.6°C)
Humidity Setpoint 50% 20-80% RH
Humidity Sensitivity 5% 1-30% RH
High Temperature Alarm 80°F 35-95°F (2-35°C)
Low Temperature Alarm 65°F 35-95°F (2-35°C)
High Humidity Alarm 60% 15-85% RH
Low Humidity Alarm 40% 15-84% RH
Liebert® Mini-Mate2
™
44
6.4 Status
The operator can monitor the percentage heating, cooling, dehumidifying and humidifying status of
the unit by selecting the “STATUS” sub-menu.
6.5 Active Alarms
The operator can monitor the alarms status by selecting “ALARMS” which will display a “No Alarm
Present” or “Alarm XX of YY” alert and description. If more than one alarm is activated, use the
Up/Down Arrow to scroll through the alarms list. (“XX” reference is the number of the alarm shown,
while the “YY” reference is the total number of alarms activated).
6.6 Time
The controller clock must be set to allow for the setback control. The clock uses the 24-hour system
(i.e., 12 midnight is displayed as 24:00). To change the time, press Enter to select the function, then
use the Up/Down arrow to change the first character, press Enter to store, then press the Up/Down
arrow to change the section character, press Enter to store, etc. THERE IS A BATTERY BACKUP
FOR THE DATE AND TIME FEATURES.
6.7 Date
The controller date must be set to allow for the setback control. To change the date press “Enter,”
then use the Up/Down arrow to change the first character, press Enter to store, press the up/down
button to change the second character, etc.
Microprocessor Control
6.8 Setback
The microprocessor can be programmed for night and weekend setback. Two (2) events can be
programmed per day for a five-day workweek and two (2) events can be programmed for a two-day
weekend. Table 22 can be used to devise a setback plan.
Table 22 Microprocessor night and weekend setback
Time 1
Temperature 1
Sensitivity 1
Humidity 1
Humidity Sensitivity 1
Time 2
Temperature 2
Sensitivity 2
Humidity 2
Humidity Sensitivity 2
Event Weekend Weekday
45 Liebert® Mini-Mate2
™
6.9 Setup Operation
Selecting Setpoint/Setup from the Main Menu will display the following selections:
• RESTART TIME DELAY
• C/F DEGREES
• HUMIDITY CONTROL METHOD
Use the Up/Down Arrow to scroll through the submenu. Press Enter to select a particular function.
6.9.1 Restart Time Delay
This function delays unit restart after main power is restored to the unit. If several systems are
operating, the time delays should be set to different values to cause a sequential start. Delay can be
set from 0.1 to 9.9 minutes (6 to 594 seconds). Setting the value to zero (0) will prevent unit restart
when power is restored. In this case, the unit must be restarted manually by pressing the “ON/OFF”
button on the keypad.
6.9.2 C/F Degrees
The control may be selected to show readings and setpoints in either degrees Fahrenheit (°F) or
Celsius (°C). To change the value use Enter to select this function, then use the Up/Down Arrow to
change the value. Press Enter to store the value.
6.9.3 Humidity Control Method
The operator may select either relative (direct) or absolute (predictive) humidity control. If “relative”
is selected, the RH control is taken directly from the RH sensor. If “absolute” is selected, the RH
control is automatically adjusted whenever return air temperature deviates from the desired
temperature setpoint (i.e., predictive humidity control). The LCD will indicate percentage relative
humidity for both methods of control. If the “absolute” feature is selected, the adjusted humidity
reading will also be shown. When utilizing the predictive humidity control feature, the humidity level
is automatically adjusted ~2% RH for each degree difference between the return air temperature and
the temperature setpoint.
Unnecessary dehumidification can result when overcooling occurs during a dehumidification cycle.
This is due to a higher than normal RH reading caused by overcooling the room (about 2% RH for
each degree of overcooling). This drop in temperature extends the dehumidification cycle. Later, when
the dehumidification ends and the temperature rises to the setpoint, the RH reading falls. The final
RH reading will then be lower than actually desired. If the temperature drop was significant enough,
the percentage RH could be low enough to activate the humidifier.
If the absolute humidity control is selected, over-dehumidification may be avoided. When overcooling
occurs (i.e., causing an increase in the RH reading) the humidity control program estimates what the
RH will be when the dehumidification cycle ends and temperature returns to the setpoint. This allows
the dehumidification cycle to end at the proper time. The predictive humidity control can greatly
reduce energy consumption by minimizing compressor/reheat operation. Use the Up/Down Arrow key
to select the desired humidity control method.
Table 23 Setup functions, default values and allowable ranges
Function Default Range
Restart Time Delay 0.1 minute
C/F Degrees °F °C or °F
Humidity Control Rel Relative or Absolute
Microprocessor Control
0 to 9.9 min
(0 = manual restart)
6.10 Change Passwords
The display will prompt the operator to enter a three digit password when attempting to make
changes. The system includes two (2) passwords: one for setpoints and one for setup. The system
allows the password to be changed by first entering the default password set at the factory (1-2-3) for
setpoints and (3-2-1) for setup. The password function provides system security, so that only
authorized personnel are allowed to make changes to the system. (If unauthorized changes are being
made, the passwords may be compromised and new ones should be selected). The password function
can be disabled by setting DIP switch 8 in the wall box to ON, then resetting power to the unit.
Liebert® Mini-Mate2
™
46
6.11 Calibrate Sensors
The temperature and humidity sensor can be calibrated by selecting the CALIBRATE SENSORS
menu item. The temperature sensor can be calibrated ±5°F (2.8°C), while the humidity sensor can be
calibrated ±10% RH. When calibrating the humidity sensor, the value shown will always be % RH,
even though absolute humidity control may be selected. If absolute humidity control is selected, the
Normal Status Display will display the adjusted reading. This reading may not agree with the
relative humidity reading displayed while in calibration.
If the sensors are subject to frequent wide temperature and humidity swings, it may be necessary to
shorten the cycling by increasing the sensor time delay. If the sensors are located too close to the air
discharge, they will likely experience rapid swings in measurement. Another method in reducing
compressor cycling is to increase the temperature and/or humidity sensitivity.
6.12 Alarm Enable
Each alarm can be disabled or enabled. Use the Up/Down Arrow to select a particular alarm, press
Enter to select either enable or disable. Then press Enter again to store the change. When the alarm
is disabled it will NOT report to either the wall box beeper or the common alarm relay.
NOTE
The high water alarm will automatically shut the unit off, even if the alarm is disabled.
similarly, optional factory-installed smoke sensor is wired to shut the evaporator unit Off,
regardless of the enable/disable status.
6.13 Alarm Time Delay
Each individual alarm can be programmed with a time delay, causing the unit to delay a specified
amount of time (0-255 seconds) before recognizing the alarm. See Table 24 for the default times. The
alarm condition must be present for the full amount of the time delay before the alarm will sound. If
the alarm condition is diverted prematurely, the alarm will not be recognized and the time delay time
will automatically reset.
Microprocessor Control
NOTE
For software alarms such as loss of power and short cycle, the time delay should be left at the
factory default of 0.
Table 24 Alarm default time delays
Default Time
Alarm
Humidifier Problem 2
High Head Pressure 2
Custom Alarm #1 0
Custom Alarm #2 6
High Temperature 30
Low Temperature 30
High Humidity 30
Low Humidity 30
Short Cycle 0
Loss of Power 0
Delay (seconds)
6.14 Common Alarm Enable
Each individual alarm can be selected to activate/deactivate the common alarm relay. If the energize
common alarm function is set to YES, the relay is energized immediately as the alarm is annunciated
and de-energized when the alarm condition is diverted after the alarm has been recognized. If the
alarm is completely DISABLED, the alarm has no effect on the common alarm relay. Use the
Up/Down arrows to scroll to a particular alarm, press the Enter button to select it, then press the
Enter button again to select Yes or No.
47 Liebert® Mini-Mate2
™
6.15 Custom Alarms
The custom alarm messages can be selected from a list of standard alarm messages, or the operator
may write his/her own message. A MAXIMUM OF TWO (2) ALARM MESSAGES CAN BE
CUSTOMIZED. The two custom alarm messages will initially display the previously programmed
message but can be changed.
The text for custom alarms can be changed at any time by selecting “CUSTOM ALARMS”. To change
the text for a custom alarm, select the alarm you would like to change, 1 or 2. Using the Up/Down
Arrows, step through the list of five standard alarm messages (listed below) and two custom alarms.
Select the alarm message desired and store it by pressing Enter.
6.15.1 Standard Custom Alarm Messages
• WATER FLOW LOSS
• SMOKE DETECTED
• LOSS OF AIR FLOW
• HUMIDIFIER PROBLEM
• FILTER CLOG
6.16 Custom Text
To modify the two custom alarm messages select “CUSTOM TXT”. Then select “CUS TXT #1” or
“CUS TXT #2”. Text can be up to 20 characters in length and can be either a blank space or any of the
following alphanumeric characters and symbols:
Microprocessor Control
• A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z
• #,%,*,-
• 0,1,2,3,4,5,6,7,8 or 9
Use the Up/Down Arrows to select a character, then press Enter. The cursor will move to the next
space where you may once again use the Up/Down Arrows to select another character, etc.
LCD Contrast
The level of contrast due to the viewing angle of the Liquid Crystal Display (LCD) can be adjusted
using a potentiometer screw, inside the wall box next to the display.
Nonvolatile Memory
All critical information is stored in nonvolatile memory. Setpoints and setup parameters are kept
inside the microcontroller in EEPROM.
Equipment Options Switches
Equipment options are selected and enabled using DIP switches 1 through 7. These are on the control
board near TB1. These switches are factory-set and should not require any user changes. The setting
and function of the switches can be individually read on the LCD.
NOTE
In order to update the DIP switch settings, power must be cycled Off, then On, from the unit
disconnect switch.
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48
Table 25 Equipment switch settings (unit control board)
Switch OFF Position ON Position
1 Compressor Chill Water
2 Staged Reheat SCR Reheat
3 Not Used--Must remain in OFF position
4 Not Used--Must remain in OFF position
5 Enable Reheat Disable Reheat
6 Enable Humidifier Disable Humidifier
7 Enable Dehumidifier Disable Dehumidifier
8 Electric Reheat Gas Reheat
Table 26 Switch settings (wall box board)
Switch OFF Position ON Position
1 Disable Beeper Enable Beeper
2 Not Used--Must remain in OFF position
3 Not Used--Must remain in OFF position
4 Not Used--Must remain in OFF position
5 Not Used--Must remain in OFF position
6
7 Disable Setback Enable Setback
8 Enable Password Disable Password
Compressor on continuously
for tight control
Economy Mode
Microprocessor Control
49 Liebert® Mini-Mate2
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6.17 Run Diagnostics (Available On Rev 1.001.0 and Higher)
By selecting Run Diagnostics, maintenance personnel can check system inputs, outputs and conduct a
test of the microcontroller circuit board from the wall box control. A review of the system inputs and
the microcontroller test can be done without interrupting normal operation.
Show Inputs
With the unit on and the fan running, the input states may be displayed for the following devices:
High Water Alarm: Normally off unless High Water Alarm is active.
• High Head Pressure Alarm: Normally Off unless High head Pressure alarm is active.
• Custom alarm #1: Normally Off unless this special customer selectable alarm is active.
• Custom alarm #2: Normally Off unless this special customer selectable alarm is active.
• Power: Normally On unless unit is turned off through the wall box, or any of these optional
devices: high temperature sensor, smoke detector, high water alarm or remote shutdown
Test Outputs
When this feature is selected, the unit is effectively turned Off. When stepping from one load to the
next, the previous load is automatically turned Off. The loads can also be toggled on/ off by selecting
“ENTER”. Once turned on, the output will remain on for five minutes unless toggled off or the test
outputs function is exited by selecting “MENU/ESC” (Compressor is limited to 15 seconds on to
prevent damage.)
Microprocessor Control
NOTICE
Risk of overheating the compressor during the Test Outputs mode. Can cause compressor
damage.
Testing the compressor output for more than a few seconds can damage the compressor. Do
not operate the unit in the Test Outputs mode any longer than is necessary for
troubleshooting.
NOTICE
Risk of extended unit operation in the Test Outputs mode for troubleshooting. Can cause
damage to unit.
DO NOT operate unit in the Test Outputs mode any longer than is necessary for
troubleshooting
The outputs are:
• Normal Fan: Normal speed fan contactor
• Low Speed Fan: Low speed fan contactor
• Humidifier: Humidifier contactor
• Cool: Compressor contactor
• HGBP: Hot gas bypass valve
• Reheat: Reheat contactor
• Common Alarm: Common alarm relay
NOTE
Fan turned on with all loads.
Test Control Board
By selecting this function, the microcontroller will perform a self test lasting approximately 10
seconds. When the test is complete, the display will show the ROM checksum, ROM part number and
firmware vision number.
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Figure 27 Control menu
Status Display
75 F 50 %RH
NO ALARMS
Menu
Setpoints
Status
Active Alarms
Time
Date
Setback
Setup Operation
Setpoint Password
Setup Password
Calibrate Sensors
Alarm Enable
Alarm Time Delay
Common Alarm
Enable
Custom Alarms
Custom Text
Diagnostics
End of Menu
Setpoints / Setup
Temp Setp t
Temp Sen s
Hum Setpt
Hum Sens
Hi Temp Alm
Lo Temp Alm
Hi Hum Alrm
Hi Hum Alm
Lo Hum Alm
Status
Heat% 0
DX Cool% 0
Dehumidify% 0
Humidify% 0
Active Alarms
No Alarms
or
Alarm 01 of 01
High Head
Time
Date
Setback
Wknd Time 1
Wknd Temp 1
Wknd Tsens 1
Wknd Humd 1
Wknd Hsens 1
Wknd Time 2
Wknd Temp 2
Wknd Tsens 2
Wknd Humd 2
Wknd Hsens 2
Wkdy Temp 1
Wkdy Tse ns 1
Wkdy Humd 1
Wkdy Hsens 1
Wkdy Time 2
Wkdy Temp 2
Wkdy Tse ns 2
Wkdy Humd 2
Wkdy Hsens 2
Setup Operation
Restart TD
C/F Degrees
Humidity Control
Dipswch 00000000
Pos 12345678
Setpoint Pas sword
Enter New PSW
Setpt PSW = 000
Diagnostics
Test Inp uts
Test Outputs
Test Microcontroller
Custom Text
Custom Text 1
Custom Text 2
Custom Alarms
Custom Alarm 1
Custom Alarm 2
Common Alarms Enable
Hi Water
Hi Head
Custom #1
Custom #2
HighTemp
Low Temp
High Hum
Low Hum
Short Cyc
Loss Pwr
Alarms Enable
Custom #1
Custom #2
HighTemp
Low Temp
High Hum
Low Hum
Short Cyc
Loss Pwr
Setup Password
Enter New PSW
Setup PSW = 000
Calibrate Sensors
Temp Cal
Hum Cal
Temp D elay
Hum Delay
Alarm Time Delay
Custom #1
Custom #2
HighTemp
Low Temp
High Hum
Low Hum
Short Cycle
Loss Pwr
Microprocessor Control
51 Liebert® Mini-Mate2
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Figure 28 Control board (inside evaporator)
Wall Box
DIP switches 1-8
Microprocessor Control
TB2-4 Hot Gas Bypass TB1-3 Customer Alarm Connection #2
TB2-3 High Head Alarm Connection TB1-2 Customer Alarm Connection # 1
TB2-2 Heat Rejection TB1-1 Customer Alarm Connection (Common)
TB2-1 Heat Rejection TB3-4 Connection to TB3 Pin 4 of wall box
TB1-9 Condensate Pump Aux Alarm TB3-3 Connection to TB3 Pin 3 of wall box
TB1-8 Condensate Pump Aux Alarm TB3-2 Connection to TB3 Pin 2 wall box
TB1-7 Common Alarm Connection TB3-1 Connection to TB3 Pin 1 of wall box
TB1-6 Common Alarm Connection TB4-2 Site Monitoring Connection (-)
TB1-5 Remote Shutdown TB4-1 Site Monitoring Connection (+)
TB1-4 Remote Shutdown P16 Remote Sensor Connection
Figure 29 Wall box board
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System Performance Microprocessor Controls
7.0 SYSTEM PERFORMANCE MICROPROCESSOR CONTROLS
This section provides a detailed description of how the Liebert Mini-Mate2 responds to operator
inputs and room conditions.
7.1 Temperature Control
7.1.1 Cooling/Heating Required
The temperature control program for the microprocessor is based on a calculated percentage
requirement for cooling/heating.
7.1.2 Cooling Operation (Cooling, Compressorized Direct Expansion and Chilled Water)
Cooling is ACTIVATED when the temperature control calculates a requirement for cooling of 100%. It
is DEACTIVATED when the cooling requirement drops below 50%. The optional hot gas bypass is
energized when a call for cooling occurs, unless there is also a call for dehumidification.
Table 27 Cooling and dehumidification load response of hot gas bypass
Situation Response
Cooling only ON
Dehumidification only OFF
Cooling with Dehumidification OFF
53 Liebert® Mini-Mate2
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7.1.3 Heating Operation
!
!
Liebert
Unit
Control
Current
Sensing
and
One-Shot
Control
Circuit
Current
Transformer
BR - Backup
Contactor
If Present
RH - Reheat
Contactor
Or
SCR Control
Reheat
Assembly
RH Contactor Or
BR Contactor,
As Required
ALM
ALM
24G
24H
24G
24H
24DG
24DH
CT2
CT1
Jumper
Electric Heat or Hot Water
The reheat stage is ACTIVATED when the temperature control calculates a requirement of 100%.
Conversely, the reheat is DEACTIVATED when the heat requirement is 50% less than the activation
point.
Ground Current Detector (GCD)
A Ground Current Detector is factory-installed on all 1-ton through 3-ton Liebert Mini-Mate2 units
with reheat. The GCD detects reheat leakage current and shuts down operation of the reheat. A
steady green LED indicates that the reheat is operating properly. A red LED indicates that the reheat
has failed and both the reheat element and GCD need to be replaced.
WARNING
Do not remove or disable the ground current detector. Failure to leave the GCD in place could
result in smoke or fire.
Figure 30 Ground current detector
System Performance Microprocessor Controls
Liebert® Mini-Mate2
WARNING
Risk of heater element failure, smoke and fire. Can cause building and equipment damage,
injury or death.
Do not remove or disable the ground current detector.
™
54
System Performance Microprocessor Controls
SCR Electric Reheat
The SCR (Silicon Controlled Rectifier) controller proportionally controls the stainless steel reheat
feature to maintain the selected room temperature. The rapid cycling made possible by the SCR
controller provides precise temperature control, while the constant element temperature improves
heater life. During operation of the SCR control, THE COMPRESSOR OPERATES
CONTINUOUSLY. The heaters are modulated to provide temperature control. The display status
will show when the unit is cooling and heating. The control will automatically lock the compressor
cooling to “ON” position, except when the temperature falls below the low temperature alarm
setpoint. Cooling will then be disabled until the room temperature reaches this minimum
temperature setpoint.
7.2 Humidity Control
7.2.1 Dehumidification/Humidification Required
The humidity control is based on a calculated percentage requirement for dehumidification or
humidification (i.e., the difference between the return air humidity and the humidity setpoint). As the
return air humidity rises above the humidity setpoint, the percent dehumidification required
increases proportionally from 0% to 100% over a humidity band equal to the humidity sensitivity
setting. The converse is true for percent humidification requirement.
7.2.2 Dehumidification Operation, Compressorized Direct Expansion (DX) Systems
Dehumidification with the standard configuration is accomplished by operating the compressor
without the hot gas bypass active. On cooling units with direct drive motors, the fan will operate at
low speed unless the cooling requirement reaches 100%. At that point, the low speed fan is disabled
(unless manually overridden by the user) until the cooling requirement decreases to 0%.
Dehumidification will also be disabled if the heating requirement exceeds 125%. It will be re-enabled
when the heating requirement reaches 50%.
7.2.3 Humidification Operation
The canister humidifier is activated when the humidity control calculates a requirement of 100%
humidification, and it is deactivated when the humidification requirement falls below 50%.
7.3 Load Control Features
The control system monitors the compressor and prevents it from turning on within a 3-minute period
of being off. If this on-off-on cycle occurs too often (e.g., 10 times in a one-hour period), a Short Cycle
Alarm will occur.
7.3.1 Communication
The control system uses a two-wire, RS-422 channel to communicate with Liebert Site Products via a
proprietary protocol. A converter board (ECA2) is available to allow communications with a “dumb”
terminal or a computer using RS-232 channel. More details are provided in the Site Products and
ECA2 user manual.
The communications channel provides both monitoring and control options, including:
• TEMPERATURE/HUMIDITY: Current temperature and humidity readings.
• STATUS (%): Cooling/heating and humidify/dehumidify operating status.
• PRESENT ALARMS: Alarms currently activated.
• SETPOINTS:
• Temperature Setpoint
• Temperature Sensitivity
•Humidity Setpoint
• Humidity Sensitivity
• High Temperature Alarm
• Low Temperature Alarm
• High Humidity Alarm
• Low Humidity Alarm
• ON/OFF STATUS
• SILENCE ALARM
55 Liebert® Mini-Mate2
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8.0 ALARMS
The microprocessor control system will audibly and visually signal all ENABLED Alarms (including
two (2) custom alarms). These special alarms can be chosen from the optional alarm list and/ or can
have their own fully custom text. The custom alarm inputs are contact closures wired from terminal
TB1-1 through a normally open contact to either TB1-2 (alarm 1) or TB1-3 (alarm 2). The alarms can
be enabled/disabled (refer to 6.0 - Microprocessor Control) and a time delay of 0-255 seconds can
be set. The alarms can also be programmed to either sound the alarm & activate the common alarm
relay OR to sound the alarm only.
When a new alarm occurs, it is displayed on the screen and the audible alarm is activated. (If
communicating with a Liebert Site Product, the alarm is also transmitted). The message “PRESS
ALARM SILENCE” will prompt the operator to silence the alarm. After the alarm is silenced, the
display will return to the Normal Status Display. Alarms can be reviewed by selecting the “ACTIVE
ALARMS” feature. The alarms can also be silenced through communications with a Liebert Site
Products Unit.
Many alarms will reset automatically when the alarm condition is no longer represented and only
after it has been acknowledged by being “Silenced.” The exceptions are:
1. Software alarms (i.e., Loss of Power and Short Cycle) will reset automatically 30 seconds after
being silenced or acknowledged; and
2. Specific alarms monitoring overload or high pressure switches may require a manual reset
depending upon the model.
Alarms
8.1 Standard Alarms: Definitions and Troubleshooting
The following list provides a definition and troubleshooting suggestions for each type of alarm. Refer
to 11.0 - Troubleshooting for additional details. If you need further assistance, contact your Liebert
supplier. THE CUSTOMER MUST SPECIFY ALARM(S) AT THE TIME OF ORDER. OTHER
DEVICES AND WIRING MAY BE REQUIRED AT THE FACTORY FOR SOME OF THE ALARMS.
8.1.1 Custom Alarms
Custom alarm(s) messages are programmed at the LCD. The message displayed may be included in a
list of provided alarms or it may be customized text (for up to 2 alarms). IF CUSTOMIZED TEXT IS
USED, MAINTENANCE PERSONNEL SHOULD BE INFORMED OF THE ALARM FUNCTION
AND THE REQUIRED ACTION.
8.1.2 High Head Pressure
Compressor head pressure is monitored with a pressure-sensor switch. (One SPDT pressure switch is
used) for the compressor in the unit.
If head pressure exceeds 400 psig (2785 kPa), the switch opens the compressor contactor and sends an
input signal to the control. The high head pressure condition is acknowledged by pressing the alarm
silence button on the wall box, which will clear the alarm if the high head pressure condition no
longer exists. If the compressor is off for 1 hour, the control goes into a special cold start mode. In the
cold start mode on a call for cooling or dehumidification, the liquid line solenoid valve (LLSV) is
energized. If the high pressure switch does NOT trip within 10 seconds, the control returns to normal
operation of monitoring the high head pressure switch for three occurrences in a 12 hour period. It is
a rolling timer and after the third high head alarm occurs and is acknowledged by the user, it will
lock off the compressor.
If while in the cold start mode, the high head pressure switch DOES trip within 10 seconds of the
activation of the LLSV, the control does not annunciate the alarm. The control will turn off the LLSV
and delay 10 seconds. The control will permit this occurrence two more times or a total of 3 times. If
on the fourth try, the high head pressure switch trips within 10 seconds, the control will annunciate
the alarm, turn off the LLSV, wait for the user to acknowledge the alarm and hold the compressor off
for 3 minutes, the length of the normal short cycle control. The control will permit this occurrence
three times. On the third occurrence, the control will lock the compressor off until the control power is
reset.
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Air-Cooled Systems
Check for power shut off to the condensing unit, condenser fans not working, defective head pressure
control valves, closed service valves, dirty condenser coils or crimped lines. Also, make sure that when
the compressor contactor is energized, the side switch on the contactor closes to energize the control
circuit on the condensing unit.
Water/Glycol/ Systems
Check water regulating valves. Verify water/glycol flow (i.e., pumps operating and service valves
open). Is water tower or drycooler operating? Is the coolant temperature entering the condenser at or
below design conditions? Is AUX relay (terminals 70 & 71) operating during cooling to turn on the
drycooler?
8.1.3 Humidity Level
The humidity level alarm may be activated under the following conditions:
• High: The room return air humidity exceeds the pre-set high humidity alarm set point. Is the
unit set up for dehumidification? Check DIP switch.
• Low: The room return air humidity decreases to the high humidity alarm set point. Is the unit set
up for humidification? Check DIP switch.
• High and Low Humidity (simultaneously): The simultaneous display of two alarms results in
loss of the humidity input signal. DASHES WILL BE DISPLAYED IN THE HUMIDITY
READING DISPLAY Under these conditions, the control system deactivates both humidification
and dehumidification. Check for a disconnected cable or failed sensor.
Alarms
8.1.4 Temperature
The temperature level alarm may be activated under the following conditions:
• High: The room return air temperature increases to the high temperature alarm set point. Check
for proper set point value. Is the room load more than the unit can handle (i.e., capacity too
small)? Make sure cooling components are operating (compressor or valves).
• Low: The room return air temperature decreases to the low temperature alarm set point. Check
for proper set point value. Make sure all heating components are operating (e.g., contactors,
reheats, etc.). Are reheats drawing the proper current (refer to amp rating on nameplate).
• High and Low (simultaneously): The simultaneous display of these two alarms results in loss
of the temperature input signal (or the humidity is out of sensor range: 15 to 85% RH). Dashes
will be displayed for the temperature reading. The control system will initiate 100% cooling.
Check for a disconnected cable or a failed sensor.
8.1.5 Humidifier Problem Alarm
The Humidifier Problem Alarm will sound and display a message if any of the following humidifier
conditions occur: overcurrent detection; fill system fault or end of cylinder life.
Check fault indicator LED on the humidifier control board:
• Constant LED on = Overcurrent
• 1 second LED Flash = Fill System
• 1/2 second LED Flash = Replace Tank
8.1.6 High Water Alarm
A float switch in the evaporator pan will shutdown the evaporator on a high water level. Clear the
drain and reset power to the unit in order to clear the alarm.
8.1.7 Loss of Power
The Loss of Power Alarm will activate (after power is restored to the unit) if the unit has lost power or
the disconnect switch was incorrectly turned off before the unit On/Off switch was pressed. A Liebert
remote monitoring unit (optional) will immediately indicate loss of power.
57 Liebert® Mini-Mate2
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8.1.8 Short Cycle
A Short Cycle Alarm will occur if the compressor system has exceeded 10 cooling start attempts in a
one-hour period. This can be caused by low refrigerant level or room cooling load is small compared to
capacity of the unit. Check for leaks, crimped lines and defective components. If room load is low,
increase sensitivity to reduce cycle.
8.2 Optional/Custom Alarms
8.2.1 Change Filter
Periodically, the return air filters in the evaporator must be changed. The Change Filter alarm
notifies the user that filter replacement is necessary. A differential air pressure switch closes when
the pressure drop across the filters becomes excessive. The switch is adjustable using the procedure
on the switch label.
8.2.2 High Temperature Sensor
The optional high temperature sensor feature is a bimetal operated sensing device with a closed
switch under normal conditions. Connected between pins 1-8 and 1-9, this device will shut down the
entire unit.
8.2.3 Smoke Detected
The smoke detector senses the return air, shuts down the unit upon detection and sends visual and
audible alarm. This smoke detector is not intended to function as or replace any room smoke detection
system that may be required by local or national codes. Locate source of smoke and follow appropriate
emergency procedures.
Alarms
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9.0 SYSTEM TESTING AND MAINTENANCE
!
This section describes system testing, maintenance and replacement procedures. Use copies of the
Maintenance Inspection Checklist to record preventive maintenance inspections.
WARNING
Risk of electric shock. Can cause injury or death. Open all local and remote electric power
disconnect switches before working within the electrical enclosures.
Line side of factory disconnect remains energized when factory disconnect is Off.
9.1 System Testing
9.1.1 Environmental Control Functions
The performance of all control circuits can be tested by changing the setpoints, which actuates each of
the main functions.
9.1.2 Cooling
To test the cooling function, set the set point to a temperature of 10°F (5°C) below room temperature.
A call for cooling should register and prompt the equipment to begin cooling cycle. (Disregard any
temperature alarms). Upon completion of testing, return setpoint to the desired temperature.
9.1.3 Heating
System Testing and Maintenance
Reheat may be tested by setting the setpoint for 10°F (5°C) above room temperature. A call for
heating should register and prompt the equipment to begin heating cycle. (Disregard any
temperature alarms). Upon completion of testing, return set point to the desired temperature.
9.1.4 Humidification
To check humidification, set the humidity set point at RH 10% above the room humidity reading.
After a short delay, the canister will fill with water and steam will be produced. Upon completion of
testing, return the humidity set point to the desired humidity.
9.1.5 Dehumidification
The dehumidification performance can be tested by setting the humidity set point at R.H. 10% below
room relative humidity. On cooling units with direct drive motor, the compressor should turn on and
the fan should switch to low speed. Upon completion of testing, return humidity set point to the
desired humidity.
9.1.6 High Temperature Sensor—Optional
The optional high temperature sensor is a bi-metal operated sensing device with a closed switch
under normal conditions. Connected between Pins 1-8 and 1-9, this device will shut down the entire
unit when the inlet air temperature exceeds a preset point.
9.1.7 Smoke Detector Sensor
While the smoke sensor is located in the unit, the optional smoke sensor power supply is located in
the electric panel. It constantly samples return air through a tube. No adjustments are required.
9.1.8 Remote Shutdown
A connection point is provided for remote shutdown devices supplied by the customer. This terminal
strip is located on the printed circuit board. (Terminals TB1-4 and TB1-5 are fitted with a jumper
when no remote shutdown device is installed).
59 Liebert® Mini-Mate2
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9.2 Maintenance
9.2.1 Electric Panel
The electric panel should be inspected on a semi-annual basis for any loose electrical connections.
9.2.2 Filters
Filters are usually the most neglected item in an environmental control system. In order to maintain
efficient operation, they should be checked monthly and changed as required. ALWAYS TURN
POWER OFF BEFORE REPLACING FILTERS.
Filters can be replaced by opening either the hinged door on the return air filter box or the return air
grille (plenum version only). Replacement filters are commercially available in several efficiencies.
9.2.3 Direct Drive Blower Package
Monthly inspection of the blower package include: motor mounts, fan bearings and impellers.
Fan Impellers and Motor Bearings
Fan impellers should be thoroughly inspected and any debris removed. Check whether they are
tightly mounted on the fan shaft and do not rub against the fan housing during rotation. Although the
unit's motor bearings are permanently sealed and self-lubricating, they should be inspected monthly
for signs of wear.
For units with the optional belt drive motor/blower, the drive belt should be checked monthly for signs
of wear and proper tension. Pressing on belts midway between the sheave and pulley should produce
from 1/2" to 1" (12 to 25mm) of deflection. Belts that are too tight can cause excessive bearing wear.
System Testing and Maintenance
Belt tension can be adjusted by raising or lowering the fan motor base. Loosen nut above motor
mounting plate to remove belt. Turn nut below motor mounting plate to adjust belt tension. If belt
appears cracked or worn, it should be replaced with a matched belt (identically sized). With proper
care, a belt should last several years.
NOTE
After adjusting or changing the belt, always be certain that motor base nuts are tightened. The
bottom adjustment nut should be finger-tight. The top locking nut should be tightened with a
wrench.
Air Distribution
Since all unit models are designed for constant volume air delivery, any unusual restrictions within
the air circuit must be avoided. Note that high efficiency filters can reduce air performance and
evaporator capacity.
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9.2.4 High Static Belt Drive Blower Package (Option)
The High Static Blower option is a belt-driven blower box that is attached to the evaporator box. Belt
drive should be checked monthly for signs of wear and proper tension. The motor sheave should be
adjusted per the following chart.
Table 28 External static pressure available
2-Ton Units @
885 CFM (1504 CMH)
Sheave
Turns RPM in. (mm) in. (mm)
5 1450 1.0 (25.4) 0.4 (10.2)
4.5 1510 1.1 (28.8) 0.5 (13.6)
4 1570 1.3 (32.4) 0.7 (17.2)
3.5 1630 1.4 (36.1) 0.8 (20.9)
3 1690 1.6 (40.0) 1.0 (24.7)
2.5 1750 1.7 (44.0) 1.1 (28.7)
2 1810 1.9 (48.1) 1.3 (32.8)
1.5 1870 2.1 (52.4) 1.5 (37.1)
1 1930 2.2 (56.8) 1.6 (41.5)
0.5 1990 2.4 (61.3) 1.8 (46.1)
0 2050 2.6 (66.0) 2.0 (50.8)
ESP
3-Ton Units @
1250 CFM (2124 CMH)
ESP
System Testing and Maintenance
9.2.5 Refrigeration System
Each month the components of the refrigeration system should be inspected for proper function and
signs of wear. Since in most cases evidence of malfunction is present prior to component failure,
periodic inspections can be a major factor in the prevention of most system failures. Refrigerant lines
must be properly supported and not allowed to vibrate against ceilings, floors, or the unit frame.
Inspect all refrigerant lines every six months for signs of wear and proper support. Inspect the
capillary and equalizer lines from the expansion valve.
Suction Pressure
Suction pressure will vary with load conditions. Suction pressure normally ranges from 58psi to 75psi
(405kPa to 517kPa).
Discharge Pressure
The discharge pressure will vary greatly with load and ambient conditions (see Table 29). The highpressure switch will shut the compressor down at its cut-out setting
Table 29 Typical discharge pressure
System Design Discharge Pressure, psig (kPa)
Air-Cooled 200-300 (1380-2070)
Water-Cooled 65 to 85°F water
(18 to 29.4°C)
Glycol-Cooled 250-350 (1725-2415)
High-Pressure Cut-Out 400 (2760)
200-250 (1380-1725)
Thermostatic Expansion Valve
The thermostatic expansion valve keeps the evaporator supplied with enough refrigerant to satisfy
load conditions. Proper valve operation can be determined by measuring superheat level. If too little
refrigerant is being fed to the evaporator, then the superheat will be high. Conversely, if too much
refrigerant is being supplied, then the superheat will be low. The correct superheat setting is between
10 and 15°F (5.6 and 8.3°C).
61 Liebert® Mini-Mate2
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System Testing and Maintenance
Air-Cooled Condensing Units
Restricted airflow through the condensing unit coil will reduce the operating efficiency of the unit.
Additionally, it can result in high compressor head pressure and loss of cooling. Using compressed air
or commercial coil cleaner, clean the coil of all debris that will inhibit airflow. In winter, do not permit
snow to accumulate around the side or underneath the condenser. At the same time check for bent or
damaged coil fins and repair as necessary. Check all refrigerant lines and capillaries for vibration and
support as necessary. Carefully inspect all refrigerant lines for signs of oil leaks.
Coaxial Condensers (Water/Glycol-Cooled Condensing Units Only)
Each water or glycol-cooled module has a coaxial condenser consisting of an exterior steel tube and an
interior copper tube. If the water supply is clean, coaxial condensers do not normally require
maintenance or replacement. Should your system begin to operate at high head pressure with
reduced capacity and all other causes have been eliminated, the condenser may be obstructed or
fouled and should be cleaned or replaced.
Regulating Valves
The water regulating valve automatically regulate the amount of fluid necessary to remove the heat
from the refrigeration system, permitting more fluid to flow when load conditions are high and less
fluid to flow when load conditions are low. The valve consists of a brass body, balance spring, valve
seat, valve disc holders, capillary tube to discharge pressure and adjusting screw.
The water regulating valve is designed to begin opening at 180 psi (1240kPa) and be fully opened at
240 psi (1655kPa). The valve is factory-set and should not need adjustment. There is significant
difference in the way standard pressure and high pressure valves are adjusted. Consult Liebert
Services.
Glycol Solution Maintenance
It is difficult to establish a specific schedule of inhibitor maintenance since the rate of inhibitor
depletion depends upon local water conditions. Analysis of water samples at time of installation and
every six (6) months should help to establish a pattern of depletion. A visual inspection of the solution
and filter residue is often helpful in judging whether or not active corrosion is occurring. The
complexity of problems caused by water requires expert advice from a water treatment specialist plus
a regular maintenance program schedule. It is important to note that improper use of water
treatment chemicals can cause more severe problems than simply using none.
Proper inhibitor maintenance must be performed in order to prevent corrosion of the glycol system.
Consult your glycol manufacturer for proper testing and maintenance procedures. Do not mix
products from different manufacturers.
Hot Gas Bypass
Operation
The hot gas bypass valve is installed between the compressor discharge piping and suction piping,
bypassing the condenser and evaporator coils. The discharge gas mixes with the suction gas, raising
the suction temperature and pressure and decreasing the mass flow through the evaporator. The
higher suction temperatures could cause compressor overheating, therefore a separate liquid
quenching valve is provided to mix refrigerant from the system liquid line with the discharge gas
before mixing with the suction gas entering the compressor.
During normal operation, when the evaporator is under full load the hot gas bypass equalizer
pressure will remain high enough to keep the valve port closed. If the evaporator load decreases, the
evaporator temperature and pressure will drop. When the suction pressure reduces below the hot gas
bypass valve setting the hot gas bypass valve opens diverting some of the refrigerant flow back to the
compressor suction. The liquid quenching valve bulb senses this increased superheat and opens,
allowing liquid refrigerant to mix with the discharge gas, desuperheating it.
Proper mixing of the three refrigerant paths ensures stable operation and system performance. The
liquid quenching valve bulb must be located downstream of all these connections to control superheat
at the compressor inlet. Superheat settings for the liquid quenching valve are chosen to maintain
consistency with the system expansion valve. During hot gas bypass operation higher superheats,
50-60°F (19-15°C), may be observed at the compressor. The liquid quenching valve is internally
equalized and superheat is not adjustable.
Liebert® Mini-Mate2
™
62
Adjustment
1. Install the suction and discharge pressure gauge.
2. Adjust temperature setpoint to call for cooling so that the refrigeration compressor will run
continuously.
3. Remove the TOP adjusting nut from the valve.
4. Insert an Allen wrench in the brass hole at top of valve in adjusting port and turn CLOCKWISE if
a higher evaporator temperature is required. Adjust no more than 1/4 turn at a time. Let the
system stabilize for 15 minutes before determining if additional adjustment are necessary.
5. After obtaining the suction pressure required, reinstall cap tightly making sure there are no
leaks.
6. Let the evaporator operate for approximately 10 to 15 minutes to make sure the suction pressure
is within the range desired.
7. There may be a fluctuation of approximately 3 to 6 PSIG (21 to 41kPa) on the evaporator due to
the differential on the hot gas bypass.
8. Return temperature setpoint to the desired setting.
Figure 31 Hot gas bypass
System Testing and Maintenance
63 Liebert® Mini-Mate2
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System Testing and Maintenance
!
Steam Generating Humidifier-Operation Procedures
Steam generating humidifiers operate efficiently over a wide range of water quality conditions and
automatically adjust to changes in the conductivity of water. The system will automatically drain and
refill to maintain an amperage set point and alert the operator when the humidifier canister needs to
be replaced.
The humidifier RUN/DRAIN switch is located in the humidifier assembly. This switch should be in
the RUN position when the humidifier is in normal operation and in the DRAIN position when a
manual drain sequence is required, such as during service. The electronic control board for the
humidifier is also located in the humidifier assembly. When the unit is energized, power is available
to humidifier. Operations involves the following steps:
1. During start-up, when the humidity control calls for humidification, the fill valve will open,
allowing water to enter the canister. When the water level reaches the electrodes, current flows
and the water will begin to warm. The canister fills until the amperage reaches the setpoint and
the fill valve closes. As the water warms, its conductivity increases and the current flow, in turn,
rises. If the amperage reaches 115% of the normal operating amperage, the drain valve opens and
flushes some of the water out of the canister. This reduces electrode contact with the water and
lowers the current flow to the amperage set point. Boiling soon commences and the canister
operates normally.
2. If the conductivity of the water is low, the canister fills and the water level reaches the canister
full electrode before the amperage set point is reached. The humidifier stops filling to prevent
overflow. Boiling should commence in time. As water is boiled off, the mineral concentration in
the canister increases and current flow also increases. The canister eventually reaches full output
and goes to normal operation. No drain is permitted until then.
3. When full output is reached the circuit board starts a time cycle which is factory-set at 60 seconds.
During this repeating time cycle, the fill valve will open periodically to replenish the water being
boiled off and maintain a “steady state” output at the setpoint. The amperage variance will
depend on the conductivity of the water.
4. After a period of time, the mineral concentration in the canister becomes too high. When this
occurs, the water boils too quickly. As the water quickly boils off and less of the electrode is
exposed, the current flow decreases. When the current crosses the low threshold point (factory-set
at 85%) before the end of the time cycle, the drain valve opens, draining the mineral laden water
out and replacing it with fresh water. This lowers the mineral concentration and returns the
canister to “steady state” operation and prolongs canister life. The frequency of drains depends on
water conductivity.
5. Over a period of time, the electrode surface will become coated with a layer of insulating material,
which causes a drop in current flow. As this happens, the water level in the canister will slowly
rise exposing new electrode surface to the water to maintain normal output. Eventually, the
steady state water level will reach the canister full electrode and indicate so by activating the
canister full alarm. At this point, all of electrode surface has been used up and the canister should
be replaced.
6. After the entire electrode surface has been coated, the output will slowly decrease. This allows for
maintenance scheduling. During these last hours of electrode life, the mineral concentration can
increase and arcing can occur. If the electrodes start to arc, turn off the humidifier immediately
and replace the canister with the identical part.
9.2.6 Humidifier Circuit Board Adjustments
WARNING
Risk of electric shock. Can cause injury or death. Open all local and remote electric power
disconnect switches before working on the humidifier printed circuit board. The printed
circuit board contains hazardous voltage. Use extreme caution. Circuit board adjustment
should be performed by properly trained and qualified personnel only.
The humidifier control board governs humidifier operation. There are three potentiometers mounted
on the board and can be used to adjust for extreme water conductivity conditions.
Liebert® Mini-Mate2
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64
System Testing and Maintenance
!
!
POT2 controls the amperage at which the drain will energize and is clearly marked in percentages.
This adjustment is factory-set at 85%, which indicates that the unit will drain when the amperage
falls off to 85% of the capacity set point. Raising the value increases the frequency of drain cycles.
Lowering the value decreases the frequency of drain cycles.
The frequency should be increased for highly conductive water and decreased for less conductive
water. If adjustment is necessary and a change of 3 to 4 percent in either direction does not permit
normal operation of the unit, consult your Liebert supplier.
The POT1 controls the duration of the drain cycle. This adjustment is factory-set at 60 seconds and
should not be readjusted without consulting your Liebert supplier.
The DIP switch settings are used to set the capacity of the humidifier. If the humidifier is replaced in
the field, the DIP switches should be set to the required settings described below.
Table 30 DIP switch settings for humidifier control board (2- and 3-ton unit
Voltage SW1 SW2 SW3 SW4 Amps
208/230 Off On Off On 6.4
220/240 Off On Off On 6.4
277 On Off Off On 5.7
380/415 Off Off On Off 3.7
460 OnOnOffOff 3.4
9.3 Replacement Procedures
9.3.1 Compressor Replacement
Infrequently, a fault in the motor insulation may result in a motor burnout (if system is properly
installed, motor burnout rarely occurs). Primarily this type of failure is due to mechanical or
lubrication problems, where the burnout is a secondary consequence.
Early detection can prevent a large percentage of the problems that can cause compressor failures.
Periodic maintenance inspections by alert service personnel (i.e., identification of abnormal
operation) can be a major factor in reducing maintenance costs. It is easier and more cost-effective to
implement the necessary preventative steps that ensure proper system operation; rather than ignore
a problem until it results in compressor failure and costly replacement. When troubleshooting a
compressor problem, check all electrical components for proper operation:
WARNING
Risk of contacting caustic substances. Can cause injury.
Avoid touching or contacting the gas and oils with exposed skin. Severe burns will result.
Wear protective clothing, safety goggles and long rubber gloves when handling contaminated
parts.
• Check all fuses and circuit breakers.
• Check pressure switch operation.
• If a compressor failure has occurred, determine whether its cause is an electrical or mechanical
problem.
WARNING
Risk of explosive discharge of high pressure refrigerant. Can cause serious injury.
This unit contains fluids and gasses under high pressure. Relieve pressure before working
with piping/connections.
Mechanical Failure: If a mechanical failure has occurred, the compressor must be replaced. If a
burnout occurs, correct the problem and clean the system. It is important to note that successive
burnouts OF THE SAME SYSTEM are usually caused by improper cleaning. If a severe burnout has
occurred, the oil will be black and acidic.
65 Liebert® Mini-Mate2
™
9.3.2 Electrical Failure
In the event of an electrical failure and subsequent burnout of the refrigeration compressor motor,
proper procedures must be followed to thoroughly remove any acids that would cause a future failure.
There are two kits that can be used with a complete compressor burnout:
• Sporlan System Cleaner
• And Alco Dri-Kleener.
Follow the manufacturer's procedure. DAMAGE TO A REPLACEMENT COMPRESSOR DUE TO
IMPROPER SYSTEM CLEANING CONSTITUTES ABUSE UNDER THE TERMS OF THE
WARRANTY, THEREBY VOIDING THE WARRANTY.
Replace a Failed Compressor
Proper procedures to remove and replace the failed compressor are:
1. Disconnect power
2. Attach suction and discharge gauges to access fittings.
3. Recover refrigerant using standard recovery procedures and equipment. Use a filter-drier when
charging the system with recovered refrigerant.
NOTE
Release of refrigerant to the atmosphere is harmful to the environment and unlawful.
Refrigerant must be recycled or discarded in accordance with federal, state and local
regulations.
System Testing and Maintenance
4. Remove failed compressor.
5. Install replacement compressor and make all connections. Use a flow of dry nitrogen through the
piping during brazing to prevent formation of copper oxide scale inside the piping. Copper oxide
forms when copper is heated in the presence of air. POE oil will dissolve these oxides from inside
the copper pipes and deposit them throughout the system, clogging filter driers and affecting
other system components.
A pure dry nitrogen flow of 1-3 ft
3
/min (0.5-1.5 l/s) inside the pipe during brazing is sufficient to
displace the air. Control the flow using a suitable metering device.Pressurize and leak test the
system at approximately 150 psig (1034kPa) pressure.
6. Follow manufacturer's instructions for clean out kits.
7. Evacuate the system twice to 250 microns. Break the vacuum each time with clean, dry nitrogen.
8. Evacuate the system a third time to 250 microns.
9. Charge the system with refrigerant (R-407C) based on requirements of the evaporator,
condensing unit and lines. Refer to the unit nameplate.
10. Apply power and operate the system. Check for proper operation. Refer to Table 29.
Liebert® Mini-Mate2
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66
9.3.3 Replacing the Humidifier Canister
!
CAUTION
Risk of contact with extremely hot surfaces. Can cause injury.
The canister and steam hose may be hot. Allow time for the humidifier to cool before replacing
parts.
The proper procedure to replace the humidifier canister is:
1. Turn off the humidifier by lowering the humidity setpoint below the ambient humidity level.
Record the original setpoint.
2. Place the RUN/DRAIN switch in the DRAIN position to drain the water from the canister.
3. Return the RUN/DRAIN switch to the RUN position after the canister has drained.
4. Turn OFF the power at the main unit electric power disconnect switch.
5. Remove the cover from the humidifier cabinet.
6. Locate the power wires to the steam canister. They are connected to the canister with 1/4" quick
connects. Make note of the wiring configuration before removing any wires. Refer to schematic on
unit. Slide the rubber boot back to expose the connections. Remove the two (2) power wires and
the canister full wire. Do not loosen the screws that secure the electrodes.
7. Loosen the steam outlet hose clamps and slide the steam hose away from the canister fitting.
Release the canister clamp along the base of the canister.
8. Remove the canister.
9. Reverse previous steps to re-assemble humidifier, paying special attention to the following:
• When replacing the wiring, connect the red wire from terminal #1 on the interface to the red tip
terminal on the canister. Reconnect the power wires as before (#2 on the left and #1 on the right).
• When replacing the canister, always check the fill and drain solenoids for proper operation.
System Testing and Maintenance
67 Liebert® Mini-Mate2
™
10.0 MAINTENANCE INSPECTION CHECKLIST
Date: Prepared By:
Model #: Serial Number:
NOTE
Reheat element sheaths and fins are manufactured with stainless steel. Regular inspections
are necessary to assure proper cleanliness of the reheating element. Should inspection reveal
corrosion particles on the reheating element or adjoining surfaces (including ducts and
plenums), appropriate cleaning should be performed. Periodic reheating element replacement
may be required to meet specific application requirements.
Monthly Inspection Items
Filters Humidifier
___ 1. Check for restricted airflow.
___ 2. Check for filter.
___ 3. Wipe section clean.
Fan Section Drain Lines
___ 1. Impellers free of debris
___ 2. Bearings in good condition
Maintenance Inspection Checklist
___ 1. Check canister for mineral deposits.
___ 2. Check condition of electrodes.
___ 3. All hoses and fittings tight.
___ 4. Check water make-up valve for leaks.
___ 1. Check for obstructions and sediment
build up.
___ 2. Check for external damage and/or
corrosion.
___ 3. Check for leaks.
Semiannually
Compressor Section Flood Back Head Pressure Control (if
applicable)
___ 1. Signs of oil leaks ___ 1. Check refrigerant level.
___ 2. Vibration isolation.
Refrigeration
Water or Glycol-Cooled Condensing
___ 1. Water valve adjustment.
Cycle
___ 1. Suction pressure
___ 2. Head pressure
___ 3. Superheat
___ 4. Evaporator coil clean
___ 5. Insulation intact ___ 1. Glycol leaks
Air-Cooled Condensing Unit (if
___ 2. Water flow
___ 3. Water leaks
Glycol Pump (if applicable)
___ 2. Pump operation
applicable)
___ 1. Condenser coil clean. ___ 3. Glycol solution
___ 2. Motor mount tight. ___ 4. pH level
___ 3. Bearings in good condition.
___ 4. Refrigerant lines properly
supported.
Electric Panel
___ 1. Check electrical connections.
___ 2. Operational sequence
Notes:_______________________________________________________________________________________
Signature:
Make photocopies of this form for your records
Liebert® Mini-Mate2
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68
11.0 TROUBLESHOOTING
Table 31 Troubleshooting
Symptom Possible Cause Check Or Remedy
No power to unit Check voltage at input terminal block.
Control voltage circuit
Unit will not start
No cooling
Compressor high
head pressure
Humidifier does not
operate
breaker (at transformer)
open
Float switch relay has
closed due to high water
in the condensate pan.
Jumper not in place
“Cooling” is not displayed
at the control panel.
Short cycle prevention
control.
Compressor contactor
not pulling in.
Compressor high head
pressure.
Plugged filter/drier. Replace filter/dryer.
Low refrigerant charge.
Insufficient air flow across
condenser coil
Water/Glycol-cooled only:
No fluid flowing through
condenser.
Self-Contained, AirCooled only: Condenser
fan not operating
DIP switch not set to
enable humidifier option
“HUMIDIFY” not
displayed at control panel
Defective board
Failed humidity sensor
No water flow
Canister fill rate is not
keeping up with the
steam output.
Locate short and reset circuit breaker.
Has rubber band been removed from float switch? Check drain and line.
Access from bottom through discharge air gills. Power must be cycled at
the disconnect to reset.
Check terminal TB1-4 and TB1-5 for jumper or N/C contact. Check pins
1-8 and 1-9 for jumper, or N/C high temperature sensor contact. Check
pins 5-4 and 5-5 for jumper or N/C smoke detector contact.
Adjust TEMP control setpoint and sensitivity to require cooling.
Control software delays compressor 3 minutes cooling, from stop to start
Check for 24 VAC ± 2 VAC at terminals P4-8 and P4-4. If voltage, check
contactor. If no voltage at P4-8 and P4-4, check at terminals P2-3 and
P2-8. If voltage, check freezestat.
See below for cause.
Check pressure gauges. See Table 11 and Table 13 for recommended
pressures. At low ambient temperatures, proper refrigerant charge is
very important on units with Lee-Temp receivers.
Remove debris from coil and air inlets.
Check fluid supply to regulating valve. Adjust valve if necessary.
Check fan operation.
See DIP switch setting Table 30.
Increase humidity control setpoint and sensitivity to require
humidification.
Check voltage at P3-1 and P1-9 on interface board for 24VAC ± 2VAC. If
no voltage, check wiring and/or replace board. Check wiring from control
panel to board.
Humidity display will indicate dashes. Check wiring from
temperature/humidity board to the control board and from the wall box to
the control board. Replace wall box or temperature/humidity circuit board
(if remote).
Make sure switch is in Run position. Check humidifier water supply
(including filter screen) and check nylon overflow line if canister is full.
Check fill valve screen opening and capillary tube for obstructions.
Check water supply pressure (minimum 10 PSIG).
Troubleshooting
69 Liebert® Mini-Mate2
™
Table 31 Troubleshooting (continued)
Symptom Possible Cause Check Or Remedy
DIP switch not set to
enable reheat option
“HEAT” not displayed at
the control panel
Reheat will not
operate
Reheat safety open,
defective reheat contact
or defective board
Element is burned out Turn off power. Check element continuity with Ohm meter.
GCD has tripped Replace GCD and heating element.
Fan will not operate
at low speed when
selected from
Open wiring or failed
board
control panel.
Fan will not operate
at low speed during
dehumidification
Cooling cycle too
short
Temperature requirement
is too high.
Sensor response delay
too short
Display freezes
and control pads
Static discharge
do not respond
Condensate pump
does not operate
Continuous
Cooling*
Open or short circuit in
wiring
Failed temperature
sensor
Continuous
Heating*
Dehumidification*
Shorted wiring or failed
control board
Humidification*
Display Problem Incorrect wiring
See DIP switch settings Table 30
Increase temperature set point to require heating.
Check voltage at P2-1 and P1-9 on interface board for 24 VAC ± 2 VAC.
If voltage, check reheat contactor and reheat safety. If no voltage, check
wiring and/or replace board.
Verify “LOW FAN” is displayed at the control panel. Check for 24 VAC ±
2 VAC at terminals P3-4 and P1-9. If no voltage, check wiring and/or
replace interface board. Check fan relays.
Verify with display. Cooling requirement overrides Dehumidification.
Increase sensor response delay. See 6.11 - Calibrate Sensors.
During period of low humidity, static electricity can cause the control
program to freeze or display incorrect information. Although this is
unlikely, the control can be reset by cycling power from the disconnect
switch.
Find open or short circuit and repair power to pump.
Temperature display will indicate dashes. Check wiring from
temperature/humidity board (remote sensors) to the control board or
from control board to wall box. Replace temperature/humidity circuit
board (remote sensors) or wall box.
Check wiring and/or replace control board.
Review section 5.5.5 - Electrical Connections. Verify VDC between 5
and 6 Volts at TB-3 Pin 1 (Ground) and TB-3 Pin 2 of the control board
and wall box. If the transmit lines (TB-3 Pin 3 & 4) are not connected,
only the power LED will be lit. It will flash once every 10-12 second. If Tis connected, but not T+, TX1 will flash approximately every 2-3 second.
And the power LED will flash once every 10-12 second. If T+ and T- are
reversed, the power LED and RX1 Will be lit and flash every 10-12
second.
NOTE: Erratic operation of the unit could occur. If no LED is lit, there is
no power or the +5VDC polarity is reversed. If any of these conditions
occur, remove power from the evaporator using the disconnect switch,
and correct wiring from the control board to the wall box.
NOTE: It may take up to 20 seconds for the display to appear on the wall
box LCD after power is applied.
Troubleshooting
Liebert® Mini-Mate2
™
70
Ensuring The High Availability
Of Mission-Critical Data And Applications.
Emerson Network Power, a business of Emerson (NYSE:EMR),
is the global leader in enabling Business-Critical Continuity
™
from grid to chip for telecommunication networks, data centers,
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provides innovative solutions and expertise in areas including
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Emerson Network Power service technicians. Liebert AC power,
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from Emerson Network Power deliver Efficiency Without
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Compromise
by helping customers optimize their data center
infrastructure to reduce costs and deliver high availability.
While every precaution has been taken to ensure the accuracy
and completeness of this literature, Liebert Corporation assumes no
responsibility and disclaims all liability for damages resulting from use of
this information or for any errors or omissions.
© 2009 Liebert Corporation
All rights reserved throughout the world. Specifications subject to change
without notice.
® Lieber t is a registered t rademark of Lieber t Corporation.
All names referred to are trademarks
or registered trademarks of their respective owners.
SL-10531_REV3_02-13
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