Hitachi RAS-(2-6)HVNP1(E), Руководство по обслуживанию

Страница: 273 / 498

8 Troubleshooting
259
SMGB0087 rev.0 - 12/2013
8
Alarm code
47
Activation to Protect System from Excessively Low Suction Pressure
(Protection from Vacuum Operation)
- In the case that the evaporating temperature (Cooling: Liquid Refrigerant Piping Temperature of Indoor Unit, Heating:
Evaporating Temperature of Outdoor Unit) is lower than -37 ºC (250~350 kΩ) and the thermistor on top of compres-
sor is higher than 90 ºC for 10 minutes, retry operation is performed 3 minutes after compressor stoppage. However,
when the state occurs more than 3 times including 3 in one hour, this alarm code is indicated.
Is the thermistor THM8 of
outdoor unit connected to PCB1?
Connect it
No
Yes
Is the thermistor THM3 of indoor
unit connected to PCB?
No
Repair leaks of gas
Yes
Is resistance of THM3 and
THM8 between 0.24kΩ and
500kΩ?
Yes
Is gas leaking?
Yes
Faulty thermistor
Recharge refrigerant
No
No
Connect it
Phenomenon Cause Check item
Action
(Turn OFF Main Switch)
– Faulty indoor unit liquid refrig-
erant temperature thermistor
– Faulty outdoor unit evaporat-
ing temperature thermistor
Fault Check resistance. Replace thermistor if faulty.
Incorrect Connection Check wiring to PCB. Repair wiring and connections.
Faulty PCB (Outdoor Unit, Indoor Unit)
Replace PCB and check the
operation.
Replace PCB if faulty.
Excessively low suction
pressure (in vacuum)
Liquid line stop valve is not
open before operation
Check stop valve. Fully open stop valve.
Faulty or malfunction of
expansion Valve
Check for clogging. Remove clogging.
Check connecting wiring and
connectors.
Replace connector.
Check operating sound from
coil.
Replace coil.
Check discharge gas thermistor. Replace thermistor.
Check attaching state of
discharge gas thermistor.
Reattach thermistor.
Refrigerant Leakage
Check each temperature and
pressure.
Charge refrigerant after
vacuum pumping.
Check gas leakage part.
Correctly charge refrigerant
after repairing gas leakage.
Faulty outdoor fan at heating
operation
Faulty outdoor fan motor
Measure coil resistance and
insulating resistance.
Replace outdoor fan motor if
faulty.