Sterlco S Series Central Chilling Stations - Manual (Page 68)

Page 68 of 77 SCW Series Central Chilling Stations
10 Troubleshooting
Problem Possible Cause Solution
No power.
Check main disconnect,
fuses, wiring, and power lead
to unit.
Wrong voltage supplied to
unit.
Voltage must be within plus
or minus ten percent (±10%)
of nameplate rating.
Defective On/Off switch. Replace switch.
Control circuit fuse blown.
Replace fuse, check
transformer, check wiring for
loose wires, check for shorted
coils on contactors and
solenoids, check crankcase
heater.
Defective control transformer. Replace.
Flow switch circuit is open.
Check pump for proper
rotation.
Pump motor off on overload. Reset and test motor.
Check that the chiller pump is
running.
Check that all valves are
open.
Unit does not run.
Unit is off on flow switch or
pressure switch.
Check for defective flow
switch or pressure switch.
Freeze control set higher than
temperature of liquid in
system.
Lower freeze control setting
to 10°F (6ºC) below the
leaving temperature you
want.
Air cooled units: Check and
clean air filters. Check
condenser fans for proper
rotation. Check for dirty
condenser. Check for
condenser air obstruction.
Check for tripped motor
overload, blown fuses, or bad
condenser fan motor.
Pump runs,
compressor does not.
High pressure refrigerant
cutout switch contacts open.
Water cooled units: Check for
water valves turned on.
Check for dirty condenser.
Check water flow through
condenser.