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Operation & Maintenance Manual
The two causes of anti-freeze switch are as follows. Actually the alarm is recognized by the anti-
freeze switch of low water temperature detected by the temperature sensor. For low water tempera-
ture, the alarm setting temperature can be changed by the HMI.
In case of any mechanically welded contactor problem of the magnetic contactor of the compressor,
PLC cannot stop the compressor. Due to this reason, the alarm will not be generated in this case.
Therefore, in this case, the circuit breaker in front of the magnet contactor with the error must be
turned OFF.
Discharge temperature issue occurs when the compressor discharge temperature is 80°… or above.
This occurs when the refrigerant is insufficient or the coolant water outlet temperature is too high.
COMM error issue means the communication error between HMI device and PLC and the loose
connection is identified as the frequent cause.
•
•
•
•
• Repair or replace controller
• Charge refrigerant
• Overcharge refrigerant
• High pressure switch error
• Air mixed to refrigerant
•
• Controller DI point error
• Insufficient refrigerant
• High pressure switch trip
Pressure alarm
•
•
• Cold water pipe valve open
•
• Cold pump error
• Insufficient cold water
•
•
•
Flow alarm
• Check power
•
• Over-voltage
• Under-voltage
• Reverse phase
• Voltage imbalance
• Missing phase
•
5E alarm
•
•
•
2
)
Dp alarm
•
• Emergency switch trip
•
Emergency stop
Potential solution
Potential cause
Recognition
Displayed alarm
message
Turn the emergency switch in
clockwise direction
Review cold water
temperature sensor
Repair or replace 5E
protective switch
Repair or replace cold water
pump
Purse air and supplement
water
Change flow switch operation
setting value or replace
device
Remove overcharged
refrigerant
Repair or replace high
pressure switch
After removing refrigerant,
execute vacuum work and
recharge
Increase high pressure
switch setting
High pressure switch
setting is too low
flow switch setting or
error in device itself
Cold water pipe valve
closed
Cold water temperature
too high
Emergency switch input
(Switch off)
After compressor
operation differential,
pressure switch trip
(Switch off)
(Basic: DP<4kgf/cm
Voltage monitoring relay
trip (Switch off)
After cold water pump,
cool water switch
(Switch off)
