8. TROUBLESHOOTING
107
ENGLISH
How to act for the problem (4/4)
Problem item
Displayed contents
Cause
Action
Evaporator refrig-
erant low temper-
ature
Evaporator refrigerant
low temperature con-
tact point activated
Evaporator refrigerant temperature
is detected to be lower than set
value.
Check evaporator refrigerant temperature
Check evaporator refrigerant low temper-
ature contact status or wiring
Check pressure sensitive switch contact
status or wiring
Replace part or re-wire
Pressure abnor-
mal contact 2
Pressure abnormal
contact 2 activated
Evaporator and condenser pres-
sures are detected either to be
lower or higher than set value
Check condenser pressure.
Check evaporator pressure.
Check pressure sensitive switch con-
tact status or wiring
Replace part or re-wire
External problem
switch
External problem
switch activated
Evaporator refrigerant temperature
is detected to be lower than set
value.
Check part status or wiring.
Replace part or re-wire
Compressor
motor 2 power
switch
Compressor motor 2
power problem
Power supply problem is detected
by the motor power supply detec-
tion device.
Check part status or wiring.
Replace part or re-wire
Compressor
motor power
switch
Compressor motor
power problem
Power supply problem is detected
by the motor power supply detec-
tion device.
Check part status or wiring.
Replace part or re-wire
Cooling water
flow interlock
Chilled water flow
rate low abnormal
Flow rate signal is disconnected
during normal r operation.
Pump stopped
Flow(differential pressure) switch
setting problem
Wrong wiring
IO board malfunction
Correct set value and check
Check part status or wiring.
Replace part or re-wire
Evaporator refrig-
erant temperature
Evaporator refrigerant
temperature low ab-
normal
Delta contactor signal is discon-
nected during operation
Check part status or wiring.
Replace part or re-wire
Evaporator refrig-
erant temperature
Evaporator refrigerant
temperature low ab-
normal
Evaporator refrigerant temperature
is detected to be lower than set
value.
Check the evaporator refrigerant tem-
perature shown in micom screen.
Check the set value and correct if it is
wrong.
Communication
MAIN <-> I/O com-
munication error
Communication error between
boards
Check part status or wiring.
Replace part or re-wire
Sensor calibration
Set value is dam-
aged. Sensor needs
to be set
Sensor is not calibrated
Correct using precision resistance de-
vice
Main board
Main board reset
Main board is reset during opera-
tion
Check voltage applied to the controller
and wiring.
Remove cause of noise
Display device
Display board reset
Display board is reset during opera-
tion
Check voltage applied to micom.
Remove cause of noise. Check wiring
Summary of Contents for LCWW
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