Hitachi RAS-(3-6)HVRNM2E Service Manual page 242

8 Troubleshooting
Phenomenon
Decrease of Discharge
Gas Superheat
Faulty Discharge Gas
N O T E
• *1) Refer to section Procedure of checking other main parts for ES
procedure for the electronic expansion valve".
232
SMGB0064 rev.0 - 08/2011
Cause
Ref. cycle is different from the electrical system
Overcharged Refrigerant
Faulty Expansion Valve
Faulty PCB
Disconnected Wires for
Ex.Valve Control
Incorrect Mounting
Thermistor
Incorrect Connection
Check item
Check ref. cycle and the
electrical system
Measure pressure
Check expansion valve *1)
Replace PCB and check
Fault
operation
Check connections.
Fault Measure resistance.
Check mounting state
.(See "Alarm Code 08".)
Check connections.
Series, see on page 312 in part "Checking
Action
(Turn OFF the main switch)
Repair wiring
Correctly charge refrigerant
Replace expansion valve if
faulty
Replace PCB if faulty
Repair wiring connections
Replace thermistor if faulty
Correctly mount thermistor.
Remove looseness,
replace connector or repair
connections.