1-72
TROUBLESHOOTING
“RUN” light flickers and “ALARM” is indicated on the remote control switch.
The unit No., alarm code and the unit code is alternately indicated on the set temperature section,
and the unit No. and alarm code are indicated on the display of the outdoor unit PCB.
In case that the abnormality of alarm code 51, 52, 53 or 54 occurs three times within 30 seconds, the
alarm code of abnormality occurred for the third time is indicated. Retry operation is performed up to
second time of abnormality occurrence.
Conditions:
Inverter current is 150% of the rated current.
1*): Regarding replacing or the checking method for ISPM, refer to page 1-114.
2*): Before the checking of ISPM, refer to page 1-111 regarding electrical discharge.
Alarm
Code
Protection Activation Against Instantaneous Overcurrent of Inverter (2)
(For 24 and 30HP)
Is the compressor
running current as
same as rated
current?
Check ISPM. *1)
Restart operation.
Does it trip soon?
Are the input currents
of three phases nearly
equal? ( 3%)
+
_
Yes
Yes
Yes
Yes
It trips.
No
No
No
No
No
No (Input currents out of balance.)
It trips
immediately.
Faulty
Good
Check the
compressor.
Check the power
source capacity.
Is there any cause
of instantaneous
voltage decrease?
It trips
occasionally.
It trips
occasionally.
It trips after a
certain period.
It trips after a
certain period.
Turn off power and
disconnect U, V, W
from compressor
terminals.
Turn ON #1 of DSW1
on ISPM and restart.
Does it trip?
Check the
compressor.
Replace ISPM. *2)
Replace ISPM. *2)
Replace ISPM. *2)
Replace ISPM. *2)
Check the power
supply.
Yes (Input currents nearly equal (
±
3%).)
Is it (a)V more
during operation
when other devices
are operating?
Is it (a)V or more
during operation?
Yes
Yes
Yes
No
No
No
Is the supply voltage
380-415V
±
10% or
220V
±
10%?
Check the capacity
and wiring of the
power source.
220V 60Hz
320
170
380-415V 50Hz
380V 60Hz
Power Supply
Mark (a)
