Emerson 3000/ITR manual 7.4.10Drycooler Settings, All drycoolers are shipped at Factory Setting

Component Operation and Maintenance

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.

7.4.10Drycooler 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

		Factory Setting	Optional Setting
Aquastat #	Fans	(Glycol) (see Notes 1 and 2)	(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.

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