Hitachi RAS-(3-6)HVNC1(E) - Page 252

8 Troubleshooting
238
SMGB0087 rev.0 - 12/2013
Phenomenon Cause Check item
Action
(Turn OFF the main switch)
Decrease of
discharge gas
superheat
Refrigerant cycle is different from the electrical
system
Check refrigerant cycle
and the electrical system
Repair wiring
Overcharged refrigerant Measure pressure Correctly charge refrigerant
Faulty expansion valve
Check expansion valve
*1)
Replace expansion valve if
faulty
Faulty PCB
Fault
Replace PCB and check
operation
Replace PCB if faulty
Disconnected wires for
expansion valve control
Check connections. Repair wiring connections
Faulty discharge gas
thermistor
Fault Measure resistance. Replace thermistor if faulty
Incorrect mounting
Check mounting state.
(See Alarm Code 08.)
Correctly mount thermistor.
Incorrect connection Check connections.
Remove looseness, replace
connector or repair
connections.
N O T E
*1) Refer to section”8.4.7 Checking procedure for other parts”, in part “8.4.6 Checking procedure for the electronic expan-
sion valve for indoor and outdoor units”.