-18-
Air supply shall be unobstructed minimum
12”; air return shall be unobstructed
minimum 6”.
2) There is a gravity drain system, so the unit shall be installed level or with a
slight slope downward the drain connection and the drain line shall be installed
slope down toward the drain.
If rise-up is necessary, a condensation pump must be used.
4. Condensing Unit Installation
1) Condensing unit shall be elevated to avoid possible flooding and shaded from
direct sun. The location shall not be subject to freezing temperatures.
2) Water must be supplied to WM-250~450SCUR-WC at all times during
operation, with the maximum outlet temperature of 120 °F. A sufficient amount
of water must be provided for constant head pressure and proper cooling, but
excessive water flow will cause the unit working inefficiently.
3) The maximum permissible water pressure is 150 PSIG. If water pressure is
excessive, a pressure reducing valve must be used to reduce water pressure.
4) Service valve operation
5. Refrigeration Piping and Leak Testing
NOTE
The line connector sizes of liquid filter and indicator, the valve
connector sizes of condensing unit or the line connector sizes of
evaporator unit may not be the same as the listed refrigeration line
sizes.
If the condensing unit is installed above the evaporator unit, use the
suction line one size smaller.
Expansion and solenoid valves have been installed on the liquid line
in the evaporator unit.
The line sizes and refrigerant charges are listed as follows.
Model No.
Equivale
nt
Line Set
Liquid
Line
Sucti
on
Line
Drain
Line
Recommended
Initial Charge
WM-
2500SSIW
C
<= 75 FT
1/4"
OD
3/8”
OD
1/2”
MPT
R134a / 19
OZ
WM-
4500SSIW
C
<= 75 FT
1/4"
OD
1/2”
OD
1/2”
MPT
R134a / 26
OZ
1) The piping starts from
condensing unit’s receiver discharge valve liquid
filter liquid indicator liquid line to evaporator
unit’s liquid line connection
(assembled with solenoid valve and expansion valve) suction line connection
insulated suction line to condensing
unit’s suction valve.
2) If the line set exceeds 75 ft long, use both inverted U trap and suction
accumulator to prevent liquid from flooding back to the compressor.
3) If the condensing unit is located below the evaporator unit, use inverted U
trap to prevent liquid from flooding back to the compressor. If the elevation
