Carrier 17/19EX - Manual (Page 88)

Condenser Pump Control
The machine will monitor the CONDENSER PRESSURE and may turn on this pump if the
pressure becomes too high whenever the compressor is shut down. CONDENSER
PRESSURE OVERRIDE is used to determine this pressure point. This value is found on the
Equipment Service1 LID table and has a default value ( Table 4 ). If the CONDENSER
PRESSURE is greater than or equal to the CONDENSER PRESSURE OVERRIDE , and the
ENTERING CONDENSER WATER TEMP (Temperature) is less than 115 F (46 C), then the
condenser pump will energize to try to decrease the pressure. The pump will turn off when the
condenser pressure is less than the pressure override less 5 psi (34 kPa), or the CONDENSER
REFRIG (Refrigerant) TEMP is within 3° F (2° C) of the ENTERING CONDENSER WATER
temperature.
Condenser Freeze Prevention
This control algorithm helps prevent condenser tube freeze-up by energizing the condenser
pump relay. If the pump is controlled by the PIC, starting the pump will help prevent the water in
the condenser from freezing. Condenser freeze prevention can occur whenever the machine is
not running except when it is either actively in pumpdown or in Pumpdown Lockout with the
freeze prevention disabled (refer to Control Test table, Pumpdown/Terminate Lockout tables).
When the CONDENSER REFRIG TEMP is less than or equal to the CONDENSER FREEZE
POINT , or the ENTERING CONDENSER WATER temperature is less than or equal to the