Hitachi RCUE40AG2 Service Manual page 145

Troubleshooting
Discharge gas
control is activated
(- alarm)~
(- alarm)
Thermal relay for
compressor is
activated
(- alarm)~
(- alarm)
Compressor internal
thermostat is
activated
(- alarm)~
(- alarm)
Fan internal
thermostat is
Unit stops
activated
during
(- alarm)~
cooling
(- alarm)
operation
Pump over-current
relay is activated
( alarm)
Freeze protection
control is activated
( alarm)
pag. 143
SMGB0003 rev.0 - 01/2007
Suction gas
(Air heat exchanger side)
temperature
is excessively
high (excessive Expansion Valve Clogging Expansion Valve Clogging Expansion Valve Clogging
superheat)
Strainer Clogging Strainer Clogging Strainer Clogging
Discharge gas
Check thermistor resistance
Thermistor Failure Thermistor Failure
Fan motor bearing
failure failure
Single Phase Single Phase
Check magnetic contactor
Running Running
Motor Insulation Measure insulation
Deteriorated Deteriorated
Power Voltage excessively
Compressor Drive Power Voltage Phase
Excessive Current
Discharge pressure is
excessively high excessively high
Power Fuse melted Power Fuse melted
Loose Power Terminal
Single Phase
Running
Contact point of compressor Contact point of compressor
Motor magnetic Contactor
Compressor Bearing Compressor Bearing
Failure Failure
Compressor Motor Compressor Motor Measure insulation
insulation Failure insulation Failure
Compressor Motor Compressor Motor
Measure current of
Over-current relay
compressor motor
Failure Failure
Check freezing of water, Check freezing of water,
Pump locked
clogging of foreign particle clogging of foreign particle
Pump Over-current Pump Over-current
Check the RC value and
relay RC value
pump running current
Wrong Wrong
Pump Over-current Pump Over-current Push reset button. Check Push reset button. Check
relay Failure relay Failure the running current the running current
Check the difference of Check the difference of
Shortage of water
temperature between inlet
Flow
and outlet of chilled water and outlet of chilled water
Water Strainer Clogging Water Strainer Clogging Water Strainer Clogging
Pump reverse
Check rotative direction
rotated rotated
Air mixed Air mixed Open Air Vent Valve Open Air Vent Valve Open Air Vent Valve
Thermistor Failure
( alarm)
Check inlet temperature of
( alarm)
( alarm)
( (  alarm) alarm)
Check valve Check valve
Malfunction Malfunction
Replace or clean the strainer Replace or clean the strainer
Replace discharge gas
Lock Status
Replace magnetic switch
resistance resistance
Set voltage within working Set voltage within working
high or low high or low range during operation range during operation
Measure the voltage in each
interphase and ask Power
Imbalance
Company for the advice Company for the advice
Screw Screw
Replace contact points
Roughness Roughness
Lock Status
resistance resistance
Replace over-current Relay
Change the RC value or
replace magnetic contactor
Replace magnetic contactor
Repair to correct direction
chilled water
Replace check valve
Remove Clogging Remove Clogging Remove Clogging
thermistor thermistor
Replace fan motor
Replace fan motor
Analyze the cause
5 5
Replace power fuse Replace power fuse Replace power fuse
Retighten the screw
Replace compressor
Remove them
Increase water fl ow
Clean the strainer Clean the strainer Clean the strainer
Evacuate Air Evacuate Air
Replace Thermistor