Hitachi RCUE40AG2 Service Manual page 146

Troubleshooting
The heat load is bigger than cooling capacity The heat load is bigger than cooling capacity The heat load is bigger than cooling capacity The heat load is bigger than cooling capacity
Low pressure is excessively
low.
(Low-pressure control is
activated)
(▪ ▪ ▪ ▪ ▪ )~(▪ ▪ ▪ ▪ ▪
Unit is running,
but the cooling
capacity is
insuffi cient
High pressure is
excessively high
(High-pressure switch is
activated)
(▪ ▪ ▪ ▪ ▪ )~(▪ ▪ ▪ ▪ ▪
Propeller-fan contacts with shroud
Unit is running,
and it makes a
Noise from compressor
noise.
pag. 144
SMGB0003 rev.0 - 01/2007
Gas leakage or shortage Gas leakage or shortage
of refrigerant of refrigerant
Expansion Valve
Clogging Clogging
Strainer Clogging
Low pressure Piping
Clogging Clogging
Check Valve Malfunction
alarm)
Shortage of water fl ow
Pump Reverse Rotation Pump Reverse Rotation
Air Mixed Air Mixed
Deposits on water cooler
plates plates
Air fl ow shortage in air-
side heat exchanger
Air temperature through
air-side heat exchanger
is high
Refrigerant Excessive Refrigerant Excessive
charge charge
Non-condensable Gas in
alarm)
the Refrigerant Cycle.
High Pressure Pipe
Clogging Clogging
Expansion Valve
Clogging Clogging
Strainer Clogging
Check valve mal-function
Compressor Failure
Installation error or
loose bolt loose bolt
Liquid Compression
Oil hammer
No-current to oil heater
at compressor stopping at compressor stopping
Worn or damaged part in
the compressor the compressor
Beats of magnetic contactor Beats of magnetic contactor Beats of magnetic contactor Beats of magnetic contactor Beats of magnetic contactor Beats of magnetic contactor Beats of magnetic contactor
Vibration of cabinet Vibration of cabinet Vibration of cabinet Vibration of cabinet Vibration of cabinet Vibration of cabinet Vibration of cabinet
Calculate heat load Calculate heat load Calculate heat load
Check super-heat.
Check clogging
Check to make sure that no difference Check to make sure that no difference
of temperature before and after of the
strainer exists. strainer exists.
Check to make sure that no difference Check to make sure that no difference
of temperature between piping exists. of temperature between piping exists.
Check to make sure that no difference Check to make sure that no difference
of temperature before and after of
check valve exists. check valve exists.
Check the difference of temperature Check the difference of temperature
between inlet and outlet of chilled
water water
Clogging of Water Strainer Clogging of Water Strainer Clogging of Water Strainer
Check the rotation direction Check the rotation direction Check the rotation direction
Open the air vent valve Open the air vent valve Open the air vent valve
Check the scales inside of water cooler
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 chiller Shortage of Service Space for chiller
unit unit
Reverse Rotation of Fan Motor Reverse Rotation of Fan Motor Reverse Rotation of Fan Motor
Air Short-circuits in Chiller Unit
Another Heat Source around the Another Heat Source around the
Chiller Unit Chiller Unit
Check cycle temperature
Turn off the unit and check the relation
between water temperature and
pressure pressure
Check clogging
Check clogging
Check to make sure that no difference Check to make sure that no difference
of temperature before and after
strainer exists strainer exists
Check to make sure that no difference Check to make sure that no difference
of temperature before and after check
valve exists. valve exists.
Check pressure, cycle temperature,
and current
Investigate
Check each bolt if loosen
Check suction gas temperature, Check suction gas temperature,
pressure pressure
Check suction gas temperature and Check suction gas temperature and
oil level oil level
Check the current to oil heater.
Noise from inside of compressor
Check the roughness of contact Check the roughness of contact Check the roughness of contact
Check screws if loosen Check screws if loosen Check screws if loosen
Replace to larger unit Replace to larger unit
Charge correct quantity after Charge correct quantity after
checking gas leakage checking gas leakage
Remove clogging
Replace strainer
Remove clogging
Replace check valve
Increase water fl ow
Replace or clean the strainer Replace or clean the strainer
Repair to the correct direction Repair to the correct direction
Evacuate the air Evacuate the air
Clean water cooler
Remove it.
Secure the service space
Correct the wiring of fan motor Correct the wiring of fan motor Correct the wiring of fan motor
Repair short-circuit.
Remove heat source
Charge the correct quantity
Evacuate and charge
refrigerant again
Remove clogging
Replace strainer.
Replace check valve.
Replace compressor.
Adjust the position of propeller Adjust the position of propeller
fan fan
Tighten up.
Ensure superheat
Replace compressor
Replace oil heater.
Replace compressor.
Replace contact points Replace contact points
Tighten up Tighten up