Hitachi RCUE40AG2 Service Manual page 144

Troubleshooting
Printed Circuit
Board Failure
Pump runs,
but neither
fan nor
compressor
run.
Fan Magnetic
Contactor Failure
(Cooling Operation)
Pump and
compressor
run, but fan
does not run does not run
Printed Circuit
Board Failure
Pump and
fan run but
Compressor
compressor
Magnetic Contactor
does not
Failure
run.
Thermostat is activated. (Thermo-Off)
Discharge pressure
is excessively
Unit stops
high, so that high
during
pressure switch
cooling
activates.
operation
(C1-H1)~ (C6-H6)
Discharge gas
control is activated
pag. 142
SMGB0003 rev.0 - 01/2007
Wiring Connection Failure
Printed Circuit Board
Failure
Remote Control Switch Failure
Coil Broken Coil Broken Coil Broken Coil Broken Coil Broken
Contact Point Failure
Fan Motor Failure
Wiring Connection Wiring Connection Wiring Connection
Failure Failure
Printed Circuit Board Printed Circuit Board Printed Circuit Board
Failure Failure
Thermistor Malfunction
Coil Breaking Coil Breaking Coil Breaking Coil Breaking Coil Breaking
Contact points Failure
Compressor Motor Failure
Compressor Failure Compressor Failure Compressor Failure Compressor Failure Compressor Failure Compressor Failure Compressor Failure Compressor Failure Compressor Failure Compressor Failure Compressor Failure
Voltage at starting up is low.
Insuffi cient air in air side
heat exchanger
Air temperature through
air side heat exchanger
is excessively high
Refrigerant excessive
charge charge
Non-condensable gas in
the refrigerant cycle
High pressure pipe
clogging clogging
Expansion Valve
clogging clogging
Check Valve (Air side Check Valve (Air side Check Valve (Air side
heat exchanger side)
clogging clogging
Strainer Clogging
Chilled water inlet Chilled water inlet Chilled water inlet
temperature of Water
side heat exchanger is
excessively high excessively high excessively high
Suction gas temperature
is excessively high
(Excessively super heat)
Check circuit by tester
Check circuit by tester Check
Printed Circuit Board by self-
checking function
Operative by the unit side
Check circuit by tester Check circuit by tester Check circuit by tester
Measure the voltage between
contact points of magnetic
contactor.
Measure the interphase
resistance resistance
Check circuit by tester
Measure the thermistor
resistance
Check circuit by tester Check circuit by tester Check circuit by tester
Measure the voltage between
contact points of electromagnetic
contactor contactor
Change water temperature or Change water temperature or
change the setting temperature. change the setting temperature.
Measure the interphase
resistance resistance
Beat noise from compressor Beat noise from compressor Beat noise from compressor
Measure the voltage
Excessive dust in air side heat
exchanger exchanger
Inlet or outlet of air side heat Inlet or outlet of air side heat
exchanger is clogged exchanger is clogged
Shortage of Service Space for Shortage of Service Space for
Chiller Unit Chiller Unit
Reverse Rotation of Fan Motor
Air Short Circuits in Chiller Unit Air Short Circuits in Chiller Unit Air Short Circuits in Chiller Unit
Another heat source around
chiller unit chiller unit
Check cycle temperature.
Turn off the unit and check Turn off the unit and check
the relation between water
temperature and pressure. temperature and pressure.
Check clogging
Check the difference of Check the difference of
temperature before and after of
strainer. strainer.
Confi rm if it is within the working
range
Gas leakage or refrigerant
shortage
Repair the wiring
connection connection
Replace Printed Circuit
Board
Replace remote control
switch. switch.
Replace magnetic
contactor.
Replace fan motor
Repair the wiring
connection.
Replace thermistor
Replace magnetic
contactor
It is not failure
Replace compressor
Consult with electric Consult with electric
power company power company
Remove it.
Secure the service space
Change wiring for fan Change wiring for fan
motor motor
Remove short-circuits Remove short-circuits
Remove heat source
Charge correct quantity
of refrigerant of refrigerant
Charge refrigerant again
after the evacuation
Check clogging
Remove clogging, or
replace check valve
Replace or clean the
strainer
Check the status of heat
load in detail and take a
countermeasure
Charge correct quantity
of refrigerant after
checking gas leakage