Indication Of Micro-Computer Input/Output; Indication Of Unit Stoppage Cause - Hitachi RAS-(3-6)HVNC1(E) Service Manual

8 Troubleshooting
Indication of micro-computer input/output
Micro-computer input/output in
12
indoor unit
Micro-computer input/output in
13
outdoor unit
Indication of unit stoppage cause
14 Cause of stoppage
00 Operation OFF, Power OFF
01 Thermo-OFF (NOTE 1)
02 Alarm (NOTE 2)
03 Freeze protection overheating protection
05 Instantaneous power failure at outdoor unit (NOTE 3)
06 Instantaneous power failure at indoor unit (NOTE 4)
Stoppage of Cooling Operation due to Low Outdoor Air Tempera-
ture
07
Stoppage of Heating Operation due to High Outdoor Air Tempera-
ture
10 Demand
11 Retry due to compression ratio decrease
12 Retry due to low pressure increase
13 Retry for Pd increase prevention
15 Vacuum/discharge gas temperature increase retry
16 Retry due to discharge gas SUPERHEAT decrease
IPM error retry, instantaneous over current of inverter retry, elec-
tronic thermal activation of inverter retry, abnormal current sensor
17
of inverter retry
Retry due to inverter voltage decrease
Retry due to Inverter Overvoltage
18
Retry due to inverter transmission abnormality
19 Retry due to Expansion Valve Control
21 Forced Thermo-OFF
22 Outdoor hot start control
24 Thermo-OFF during energy saving operation mode
26 Retry due to high pressure decrease
28 Cooling air discharge temperature decrease
33 Forced Thermo-OFF (example: due to Air Filter Cleaning)
34 Forced Thermo-OFF (example: due to Motion Sensor
Retry due to abnormal operating mode
35
(Reversing valve switching failure)
39 Forced Thermo-OFF due to Power Saving Control)
279
SMGB0087 rev.0 - 12/2013
C1 
C2 -
d1 01
Heating Thermo-ON
Cooling Thermo-ON
Dark
Y52C2 Y211
Y212
Dark
Outdoor fan
N O T E 1
Explanation of term,
Thermo-ON: A condition that an indoor unit is reques-
ting compressor to operate.
Thermo-OFF: A condition that an indoor unit is not re-
questing compressor to operate.
N O T E 2
Even if stoppage is caused by "Alarm", "02" is not
always indicated.
N O T E 3
If transmission between the inverter printed circuit
board and the control printed circuit board is not per-
formed during 30 seconds, the outdoor unit is stopped.
In this case, stoppage is d1-05 cause and the alarm
code "04" may be indicated.
N O T E 4
If transmission between the indoor unit and the outdo-
or unit is not performed during 3 minutes, indoor units
are stopped.
In this case, stoppage is d1-06 cause and the alarm
code "03" may be indicated.
Alarm
H2
52H
Y52C1
Y20B
Y20A
8