Specifications

44 Catalog WSC/WDC-4
Figure 12, VFD (047 and Larger) Cooling Water Piping for Free-Standing VFD
CHILLER
VFD HEAT
EXCHANGER
* STOP
VALVE
* STRAINER
MAX. 40 MESH
WATER
REGULATING
VALVE
SOLENOID
VALVE
* DRAIN VALVE
OR PLUG
* STOP
VALVE
CHILLED
WATER
PUMP
*
Field Supplied Piping Components
(Factory Mounted)
(Factory Mounted)
* STOP
VALVE
* BALANCING
VALVE
* STOP
VALVE
OIL COOLER CIRCUIT
SOLENOID
VALVE
(Factory Mounted)
WATER
REGULATING
VALVE
(Factory Mounted)
Table 5, Cooling Requirements
McQuay
Drive Model
Number
Combined
Compressor Oil
and VFD Cooling
Copper Tube Size
Type K or L
VFD Cooling
Only Copper
Tube Size
Type K or L
Coolant
Method
Max.
Entering
Coolant
Temperature
(°F)
Min. Entering
Coolant
Temperature
(°F)
Required
Pressure
Drop
feet
Maximum
Pressure
(Water
Side) psi
VFD 019 N/A N/A Air 104 40 NA N/A
VFD 025 N/A N/A Air 104 40 NA N/A
VFD 047 1.0 7/8 in. Water (1) 90 40 10 (2) 300
VFD 060 1.0 7/8 in. Water (1) 90 40 30 (2) 300
VFD 072 1.0 7/8 in. Water (1) 90 40 30 (2) 300
VFD 090 1 1/4 1.0 in. Water (1) (3) 90 40 30 (2) 300
VFD 120 1 1/4 1.0 in. Water (1) (3) 90 40 30 (2) 300
Notes:
1. Cooling water must be from the closed, chilled water circuit with corrosion inhibitors for steel and copper, and must be piped
across the chilled water pump.
2. The required pressure drop is given for the maximum coolant temperature. The water regulating valve will reduce the flow
when the coolant temperature is below the maximum in the table. The pressure drop includes the drop across the solenoid
valve, heat exchanger and water regulating valve.
3. Models VFD 090and 120 have a separate self-contained cooling loop with a recirculating water pump and heat exchanger, but
are piped the same as all water-cooled VFDs.
Table 6, Cooling Water Connection Sizes
Free-Standing VFD Factory-Mounted VFD
Chiller Unit
Oil Cooler VFD Combined
WDC 100/126 1 1/2 in. FPT 3/4 in. MPT 1 1/2 in. FPT
WSC/WDC 050 Not Required Air-Cooled Not Required
All Others 1 in. FPT 3/4 in MPT 1 in. FPT