User Manual
Table Of Contents
- Important Safety Instructions
- SAVE THESE INSTRUCTIONS
- 1.0 Introduction
- 2.0 Startup
- 3.0 Operation with iCOM Control
- 4.0 Liebert iCOM Display Components and Functions
- Figure 2 Liebert iCOM display components
- Table 1 Keyboard icons and functions
- Figure 3 Liebert iCOM default screen symbols
- 4.1 Navigating Through the Liebert iCOM Display
- 4.2 Changing Operational Settings
- 4.3 Changing Liebert iCOM’s Display Settings
- 4.4 Graphical Data Record
- 4.5 Liebert iCOM Service Menu Icons and Legend
- 4.6 Wiring for Unit-to-Unit Communications—U2U
- 4.7 Entering Network Setup Information
- 4.8 Viewing Multiple Units with a Networked Large Display
- 5.0 Operation
- 6.0 Alarm Descriptions
- 6.1 Standard Alarms
- 6.1.1 Change Filter
- 6.1.2 Compressor Overload
- 6.1.3 High Head Pressure
- 6.1.4 High Humidity
- 6.1.5 High Humidity and Low Humidity (Simultaneously)
- 6.1.6 High Temperature
- 6.1.7 High Temperature and Low Temperature (Simultaneously)
- 6.1.8 Humidifier Problem
- 6.1.9 Loss of Air Flow
- 6.1.10 Loss of Power
- 6.1.11 Low Humidity
- 6.1.12 Low Suction Pressure
- 6.1.13 Low Temperature
- 6.1.14 Main Fan Overload
- 6.1.15 Short Cycle
- 6.2 Optional Alarms
- 6.3 Set Alarms—User Menus
- 6.1 Standard Alarms
- 7.0 Component Operation and Maintenance
- 7.1 System Testing
- 7.2 Filters
- 7.3 Blower Package
- 7.4 Refrigeration System
- 7.4.1 Suction Pressure
- 7.4.2 Discharge Pressure
- 7.4.3 Superheat
- 7.4.4 Thermostatic Expansion Valve
- 7.4.5 Hot Gas Bypass Valve—Not Available on Digital Scroll Units
- 7.4.6 Air Cooled Condenser
- 7.4.7 Water/Glycol Cooled Condensers
- 7.4.8 Motorized Ball Valve—Digital Scroll Compressor
- 7.4.9 Regulating Valve—Scroll Compressor
- 7.4.10 Drycooler Settings
- 7.4.11 Compressor Oil
- 7.5 Compressor Replacement
- 7.6 Facility Fluid and Piping Maintenance for Water and Glycol Systems
- 7.7 Humidifier
- 8.0 Troubleshooting
- Table 12 Blower troubleshooting
- Table 13 Chilled water troubleshooting
- Table 14 Compressor and refrigeration system troubleshooting
- Table 15 Dehumidification troubleshooting
- Table 16 Glycol pump troubleshooting
- Table 17 Infrared humidifier troubleshooting
- Table 18 Steam generating humidifier troubleshooting
- Table 19 Reheat troubleshooting
- 9.0 Monthly Maintenance Inspection Checklist
- 10.0 Semiannual Maintenance Inspection Checklist

Component Operation and Maintenance
45
To raise the head pressure setting, turn the adjusting screw counterclockwise until the desired set-
ting is obtained.
Figure 24 Johnson Controls valve adjustment
Manual Flushing—The valve may be flushed by inserting a screwdriver or similar tool under the
two sides of the main spring and lifting. This action will open the valve seat and flush any dirt parti-
cles from the seat. If this fails, it will be necessary to disassemble the valve and clean the seat.
High Pressure Valve - 350 PSIG System (2413 kPa) for 3 Ton Units (Metrex Valve)
Adjustment—The valve may be adjusted using a 1/8" diameter rod. Turn adjusting collar nut coun-
terclockwise to raise head pressure. Turn it clockwise to lower head pressure. Rotation directions are
as viewed from top of valve spring housing.
Figure 25 Metrex valve adjustment
Range
Spring
Valve
Spring
Guide
Top
Retainer
Range Adjustment Screw
Insert screwdrivers under
the valve spring guide.
Adjusting Collar Nut