Liebert DS 12.11.3Drycooler Settings, Aquastat settings-two-fan through four-fan drycoolers

Maintenance

12.11.3Drycooler Settings

Applications with the Optional Stat Setting require field piping to be insulated to prevent condensa- tion. Table 57 shows acceptable applications where stats must be adjusted to Optional Setting. Aqu- astats 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 DS units with digital compressors). These units have a “D” or “G” in the seventh character: DS/VS/xxxxD or DS/VS/xxxxG.

Table 57 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*	Optional	Optional	Optional	Optional	Optional	Factory	Factory	Factory
Insulate Field Piping	Yes	Yes	Yes	Yes	Yes	No	No	No

* See Tables 58 through 60

MBV=motor ball valve; WRV=water regulating valve

Table 58 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)

Table 59 Aquastat settings—six-fan drycoolers

Dial Setting (Stat Open Temp) Set for Mid Differential 8°F (4.4°C) Rise to Close

		Stat Location	Factory Setting	Optional Setting
Aquastat #	Fans	Cabinet	(Glycol) (see Notes 1 and 2)	(GLYCOOL) (see Note 3)
AQ1	F1	Main	65°F (18.3°C)	35°F (1.7°C)
AQ2	F2	Main	70°F (21.1°C)	40°F (4.4°C)
AQ3	F3 & F4	Auxiliary	73°F (22.8°C)	43°F (6.1°C)
AQ4	F5 & F6	Auxiliary	75°F (23.9°C)	45°F (7.2°C)

Table 60 Aquastat settings—eight-fan drycoolers

Dial Setting (Stat Open Temp) Set for Mid Differential 8°F (4.4°C) Rise to Close

		Stat Location	Factory Setting	Optional Setting
Aquastat #	Fans	Cabinet	(Glycol) (see Notes 1 and 2)	(GLYCOOL) (see Note 3)
AQ1	F1	Main	65°F (18.3°C)	35°F (1.7°C)
AQ2	F2	Main	70°F (21.1°C)	40°F (4.4°C)
AQ3	F3 & F4	Auxiliary	73°F (22.8°C)	43°F (6.1°C)
AQ4	F5 & F6	Auxiliary	75°F (23.9°C)	45°F (7.2°C)
AQ5	F7 & F8	Main	78°F (25.6°C)	48°F (8.9°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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