Emerson Liebert Challenger With Liebert iCOM Control 3000/ITR - Manual (Page 52)

Component Operation and Maintenance
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Manual Flushing—The valve may be flushed by rotating the socket head screw clockwise. This
screw must be in the OUT position (counterclockwise) for normal valve operation.
Valve Disassembly
1. Shut off the water supply by using isolating valves.
2. Relieve the tension on the main spring by turning the adjusting screw (or collar) as far as it will
go (provide a container to catch water below the valve).
3. Remove four screws extending through the main spring housing.
4. Remove the center assembly screws for access to all internal parts.
5. Clean the seat if possible. If the seat is pitted or damaged, replace the valve rubber disc and valve
seat.
6. After valve is reassembled check for leaks.
7. Readjust head pressure control.
Testing Function of Valve—When the refrigeration system has been Off for approximately 10 to 15
minutes, the water flow should stop.
If the water continues to flow, the valve is either improperly adjusted (with head pressure too low) or
the pressure sensing capillary is not connected properly to the condenser.
7.4.10 Drycooler Settings
Applications with the Optional Stat Setting require field piping to be insulated to prevent condensa-
tion. Table 8 shows acceptable applications where stats must be adjusted to Optional Setting.
Aquastats must be field-adjusted to Optional Setting for:
• GLYCOOL/Dual Cool applications
• Single Drycooler loops with motor ball valve flow controls (motor ball valves are used on all Lie-
bert Challenger 3000 and ITR units with digital compressors).
Table 8 Water/glycol system conditions requiring optional settings for aquastats
Cooling Type Glycool Glycol
Flow Control MBV WRV MBV WRV
Drycoolers in Loop 1 Multiple 1 Multiple 1 Multiple 1 Multiple
Stat Setting 1 Optional Optional Optional Optional Optional Factory Factory Factory
Insulate Field Piping Yes Yes Yes Yes Yes No No No
1. See Table 9.
2. MBV=motor ball valve; WRV=water regulating valve
Table 9 Aquastat settings—two-fan through four-fan drycoolers
Dial Setting (Stat Open Temp) Set for Mid Differential 8°F (4.4°C) Rise to Close
Aquastat # Fans
Factory Setting
(Glycol) (see Notes 1 and 2)
Optional Setting
(GLYCOOL) (see Note 3)
AQ1 F1 65°F (18.3°C) 35°F (1.7°C)
AQ2 F2 & F3 75°F (23.9°C) 45°F (7.2°C)
AQ3 F4 70°F (21.1°C) 40°F (4.4°C)
NOTE
1. All drycoolers are shipped at Factory Setting.
2. Factory Setting is used for all glycol applications, except single drycooler loops with motor
ball valve controls.
3. Stats must be field-adjusted to Optional Setting for GLYCOOL/Dual Cool applications
and all single drycooler loops using motor ball valve flow controls.