Liebert Precision Cooling System DS - Manual (Page 131)

Maintenance
121
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
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)
Table 59 Aquastat settings—six-fan drycoolers
Dial Setting (Stat Open Temp) Set for Mid Differential 8°F (4.4°C) Rise to Close
Aquastat # Fans
Stat Location
Cabinet
Factory Setting
(Glycol) (see Notes 1 and 2)
Optional Setting
(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
Aquastat # Fans
Stat Location
Cabinet
Factory Setting
(Glycol) (see Notes 1 and 2)
Optional Setting
(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.