Hitachi RHUE-3AVHN, Руководство по обслуживанию

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173
Initial troubleshooting
SMGB0066 rev.0 - 12/2009
Troubleshooting
Service Manual
7
Abnormal operation of the devices (Cont.)
observed failure Cause Check item
Action
(Turn off the main
switch)
Insufficient heating
process
Excessively high
discharge pressure
Non-condensable gas in
the refrigerant cycle
Turn off the unit & check
the relation between
temperature and pressure
Evacuate and charge
refrigerant again
Clogging of the high
pressure pipe
Check the clogging Remove ghe clogging
Clogging of the expansion
valve
Check the clogging Remove the clogging
Clogging of the strainer
Check the difference
temperature before/after
strainer
Replace the strainer
Water scale is attached
in the water side heat
exchanger
Check the heat exchanger Chemical cleaning
Malfunction or internal
leakage of the 4-way
valve
Check the difference
temp. between inlet &
outlet of the 4-way valve
Replace the 4-way valve
Wiring failure of the 4-way
valve
Check the electrical
continuity at the termilnals
Repair wiring or replace
4-way valve
Failure compressor
Check pressure cycle
temperature & running
current
Replace the compressor
Unit is running but does
not make any sound
Unit propeller fan is hitting the shroud Visually inspect it
Adjust the position of the
propeller fan
Abnormal sound form the
compressor
Faulty installation
Check that each part is
tightly fixed
Tightly fix each part
Liquid ref. compression
Adjust the suction gas
temperature and pressure
Ensure super-heat
Wear or breakage of the
internal compressor parts
Abnormal sound from the
inside of the compressor
Replace the compressor
No heat by the oil heater
Check the resistance of
the oil heater and it´s fuse
Replace the oil heater and
the fuse
Humming sound from the magnetic conductor
Check the surface of the
contacts
Replace the
magnetothermic switch
Abnormal vibration of the cabinets Check each fixing screw Tightly fix each screw