Alarm code
48
Activation of Inverter overcurrent protection device (2).
•
The RUN indicator flashes and the ALARM indication is displayed on the remote control switch.
•
The unit no., the alarm code and the unit code are alternatively displayed in the temperature setting section and the unit
no. and alarm code are displayed on the outdoor unit's PCB1 display.
* This alarm is indicated when instantaneous overcurrent occurs six times in thirty minutes (retry operation is carried
out up to five times).
Activation condition: Inverter current with 150% of the rated current.
Is the supply voltage 400V / 50Hz ±10%?
Is the compressor
running current as
same as activation
current? *3)
Check the diode
module. *2)
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 drop?
It trips
occasionally.
It trips after a
certain period.
Turn off power and
disconnect U, V, W
from compressor
terminals.
Turn ON #1 of DSW1
on PCB2 and restart.
Does it trip?
Check the
compressor.
Replace the diode
module.
Replace PCB2.
Replace PCB2.
Replace the
transistor module.
Check the power
supply.
Yes (Input currents nearly equal (±3%).)
Yes
Yes
Yes
No
No
No
Check the capacity
and wiring of the
power source.
Check the transistor
module (IPM). *1)
Replace PCB2.
Faulty
Normal
Check PCB2 *1)
Normal
Replace PCB2.
Faulty
Is it 323V or more during operation?
Is it 323V or more during operation when other devices are operating?
PCB1: Control PCB in Outdoor Unit
PCB2: Inverter PCB
*1) Carry out the electrical discharge when Inverter parts are checked or replaced, refer to
, see on page 267
.
*2): Before checking the diode module, refer to
Checking procedures for other main parts
, see on page 267
.
*3): Regarding the activation current value setting, refer to
, see on page 330
.
8 Troubleshooting
221
SMGB0065 rev. 1 - 12/2010
8
