Sterlco GC Series Central Chiller - Manual (Page 48)

GC Series Central Chillers Chapter 6: Troubleshooting 48 of 79
Controller Alarm Possible Cause Solution
Low Fluid Temp Fault (Leaving
fluid temperature has dropped
below the fault setpoint) Optional Hot gas bypass valve
malfunction Verify wiring EV Connection B1-4 on
EVD
Low Suction Pressure Fault
(Suction pressure has fallen below
fault setpoint) Refrigerant undercharge Contact refrigeration technician about
adding refrigerant as needed
Refrigerant leak Contact refrigeration technician about
repairing lead and adding refrigerant as
needed
Electronic expansion valve closed Verify wiring EV Connection A1-4 on
EVD
Low fluid flow through evaporator Verify evaporator inlet and outlet
butterfly valve position to achieve 10°F
(5.6°C) differential across evaporator
Clean evaporator inlet strainer
Verify evaporator pump operation
Leaving fluid temperature close to
Fluid Freezepoint Setpoint Verify Fluid Freezepoint setpoint and
glycol/water mixture for proper
freezing temperature
Low Superheat Fault (Superheat
calculated value has dropped
below fault setpoint)
Electronic expansion valve
malfunction Verify wiring at EV Connection A1-4
Contact refrigeration technician about
replacing valve as needed
Suction Pressure Sensor Failure Packard connector separated from
sensor Reconnect wire connector to sensor
Input to PLC is missing Verify wiring at EVD
Faulty sensor cable Replace cable
Faulty sensor Replace sensor
Leaving Water Temp Sensor
Failure Input to PLC is missing Verify wiring at PLC
Faulty sensor Replace sensor
Low Level Fault (optional: will
only become active if level sensor
is enabled in Supervisor Menu) Fluid level too low in tank Add fluid to pump tank to a minimum
of 18 in (46 cm) above the pump
suction centerline while the pump is
operating
Sensor failure See Level Sensor Fault
No Flow Circulation pump is faulty Verify operation of circulation pump
Input to PLC is missing Verify wiring at ID3 on PLC
M12 connector on cable separated
from sensor Reconnect M12 connector to top of
sensor.
Faulty sensor cable Replace cable
Faulty sensor Replace sensor
High Fluid Temp Fault (Leaving
fluid temperature has exceeded
fault setpoint)
Compressor fault See Compressor Fault above
Load may be too high for chiller Contact your sales representative for
assistance.
Evaporator dirty Clean evaporator inlet strainer
Back flush evaporator
Condenser Differential Pressure
Warning Condenser dirty Clean condenser
Condenser Inlet Temp Sensor
Failure Input to PLC is missing Verify wiring at PLC
Faulty sensor Replace sensor
Chiller In Fluid Temp Sensor
Failure Input to PLC is missing Verify wiring at PLC
Faulty sensor Replace sensor
Evaporator Differential Pressure Dirty evaporator Clean evaporator inlet strainer
Back flush evaporator
High Discharge Pressure Warning Dirty condenser Clean condenser
High Fluid Temp Warning Leaving fluid temperature has
exceeded warning setpoint
High Level Fault (optional: will
only become active if level sensor
is enabled in Supervisor Menu)
Fluid level in pump tank is above
fault setpoint Remove fluid from pump tank to
achieve a minimum of 18 in (46 cm)
above the pump suction centerline
while the pump is operating