Hitachi RAS-H(V)RNME-AF Service Manual page 404

12 Troubleshooting
76
Alarm code
• The alarm code is displayed on the LCD User interface.
• The alarm code is displayed on the seven segments of the indoor unit PCB.
• This alarm code is displayed when refrigerant temperature of the indoor unit is lower than -20ºC for 30 seconds.
Is the water
refrigerant tempe-
rature (THML and THMg)
measured correctly?
No
Are the
connectors between
PCB1 and PCB2 connected
correctly?
CN9-CN1
CN5-CN2
PCB1
CN6-CN3
CN2-CN4
Yes
Are thermistors
THMg & THMl
correct? (Refer to Alarms
13/14 procedures)
Yes
Faulty PCB1 or PCB2 (Check PCBs)
394
SMGB0070 rev. 1 - 08/2011
Freeze Protection Stop by indoor liquid temperature thermistor
Yes
No
PCB2
Wiring check, repair breaking of wire, wrong wiring
No
Check THMg or THMI and replace it
1
Refer to
2
Check that the refrigerant thermistors
(THML & THMg) are positioned correctly
3
Check to make sure the unit is operating within
operating range (refer to
4
Check for shortage of refrigerant gas leakage
5
Clogging of plate heat exchanger
6
Clogging of expansion valve and strainer
7
Check valve malfunction
8
Expansion valve malfunction
9
Make sure that the water volume of the installation
is above minimum required for the unit
(Refer to Installation water charge
10
Contact your local dealer
Contact your local dealer
Alarm 70 procedures
Operating range chapter)
chapter)