036-33072-001 Rev. A (0601)
Unitary Products Group
9
CONDENSOR PRESSURE CONTROL
Water regulating valves provide control of the quantity of con-
denser water supplied to the unit by sensing the condensing
temperature. The factory installed Condenser Pressure Con-
trol option provides a regulating valve for each internal con-
denser water circuit.
The water regulating valve needs to be adjusted to maintain a
leaving water temperature between 90 degrees F and 100
degrees F. If using a refrigerant discharge pressure gauge,
adjust the water valve to maintain a condensing pressure or
170 to 220 PSIG. The valve is adjusted by turning the 1/4 inch
square shaft on top of the spring housing. Turning the adjust-
ing screw counter clockwise will raise the opening pressure
and raise the condensing pressure being maintained. Turning
the adjusting screw clockwise will lower the opening point
and lower the condensing pressure being maintained. If
mains water is being used, make sure the valve closes soon
after the compressor stops. If the flow does not stop after a
few minutes, raise the opening pressure by turning the
adjusting shaft caunter clockwise until the flow stops.
If the unit is running on mains water, we recommend adjust-
ing the water regulating valve to give 100 degrees F leaving
water temperature or 220 PSIG condensing temperature.
This will give the best compromise between low water flow
and high operating efficiency. If the condenser water is being
re-circulated through a cooling tower or a chilled water sys-
tem, it is recommended that the water regulating valve to set
for a lower condensing temperature. This will provide higher
efficiency, lower operating cost and lower sound level. The
minimum condensing pressure required for satisfactory
expansion valve operation is 170 PSIG. This corresponds to a
leaving water temperature of 90 degrees F.
