Low Discharge Pressure

Probable Cause: Remedy:
Ambient air too cold.
Water supply to condenser too cold.
Install head pressure control system.
Check, repair, and adjust condenser water
cooling facilities.
Water quantity not being regulated properly through
the condenser.
Refrigerant level low.
Install or repair water regulating valve.
Evaporative condenser fan and water switches
are improperly set.
Fan cycling/variable speed not operating.
Add necessary refrigerant per proper charging
Reset condenser controls.
Uninsulated receiver in cold ambient acting as
Check motor and pressure setting.
Insulate and/or artificially heat receiver.

Failure of flooded head pressure control system (constant bypass)

Foreign material wedged between condenser
port and seat.
Wrong pressure dome on valve for system.
Hot gas bypass line restricted or shut off.
Power head has lost its charge.
Oversized condenser or condensing unit.
Pressure of condenser bypass regulator (OPR)
set too low.
Artificially raise head pressure and tap the
valve body to dislodge foreign material.
Change dome or valve.
Clear obstruction.
Change dome or valve.
Replace with properly sized condenser.
Adjust condenser bypass regulator’s setting
to appropriate level. Normally set 20 psi below
condenser pressure regulator’s (IPR) setting.