Cause Of Indoor Unit Stoppage - Hitachi RAS-(3-6)HVNC1(E) Service Manual

8 Troubleshooting

Cause of indoor unit stoppage (
Indication
Operation OFF, Power OFF
00
Thermo-OFF
01
Alarm
02
Freeze protection overheating protection
03
Instantaneous power failure at outdoor unit
05
Instantaneous power failure at indoor unit
06
Stoppage of Cooling Operation due to Low Outdoor Air
Temperature
07
Stoppage of Heating Operation due to High Outdoor Air
Temperature
Demand
10
Retry due to compression ratio decrease
11
Retry due to low pressure increase
12
Retry for Pd increase prevention
13
Vacuum/discharge gas temperature increase retry
15
Retry due to discharge gas SUPERHEAT decrease
16
IPM error retry, instantaneous over current of inverter
retry, electronic thermal activation of inverter retry, abnor-
17
mal current sensor of inverter retry
Retry due to inverter voltage decrease
Retry due to Inverter Overvoltage
18
Retry due to inverter transmission abnormality
Retry due to Expansion Valve Control
19
Forced Thermo-OFF
21
Outdoor hot start control
22
Thermo-OFF during energy saving operation mode
24
Retry due to high pressure decrease
26
Cooling air discharge temperature decrease
28
Forced Thermo-OFF (example: due to Air Filter Cleaning)
33
Forced Thermo-OFF (example: due to Motion Sensor
34
Retry due to abnormal operating mode
35
(Reversing valve switching failure)
Forced Thermo-OFF due to Power Saving Control)
39
N O T E
• The cause code for indoor unit stoppage is not always "02" (Alarm) during stoppage by the abnormality.
If the unit is under Thermo-OFF by other cause of stoppage before "02" (Alarm) occurs, the previous cause code for
indoor unit stoppage remains.
• When the transmitting between the inverter PCB and the outdoor unit PCB1 is disconnected for 30 seconds, the out-
door micro-computer will be reset. Accordingly when the alarm code "04" (Abnormal Transmitting between Inverter
PCB and Outdoor Unit PCB1) occurs, the cause code for indoor unit stoppage may be indicated "05".
• When the transmitting between the indoor unit and the outdoor unit is disconnected for 3 minutes, the indoor micro-
computer will be reset. Accordingly when the alarm code "03" (Abnormal Transmitting between Indoor Unit and Out-
door Unit) occurs, the cause code for indoor unit stoppage may be indicated "06".
• For twin, triple and quad combination, if the cause code for indoor unit stoppage "21" is indicated, check the cause of
stoppage for other indoor units.
• Cause code for indoor unit stoppage "22" is indicated when it is forced thermo-OFF during compressor preheating for
RAS-12HN(P/C) models.
296
SMGB0087 rev.0 - 12/2013
dA
)
Contents
N O T E
10 Demand thermo OFF:
Temperature Area in Heating Operation
Thermo-OFF temperature area
( C)
o
32
30
29
28
26
26
Restart
temperature area
24
23
22
20
17
5 10 15
Outdoor temperature
Forced stoppage
temperature area
19
21 23
20 25
( C)
o