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Failure mode detected by outdoor unit (Representative codes)
• The check code used varies depending on the combination with the outdoor unit.
Possible causes
Compressor breakdown
• Compressor stops due to
operating frequency decrease.
Compressor does not work.
• Overcurrent protection circuit is
activated after a certain time
from compressor startup.
Failure of current detect circuit
• Large AC current even during
compressor OFF
• Phase loss in power supply
Low-pressure switch ON
(applicable models)
COOL : 30 seconds
HEAT : 10 minutes
Other outdoor unit errors
• CDB-IPDU communication
error (connector disconnection)
• Abnormal heatsink temperature
(over specified value)
Phase detection protection circuit
activated (normal models)
Abnormal discharge temperature
(over specified value)
Failure of high-pressure
protection circuit
(Temperature over specified
value detected by TE sensor)
High-pressure switch
(normal models)
Failure of outdoor unit DC fan
Inverter overcurrent protection
circuit activated (short time)
Main circuit short voltage operation
Failure of IPDU position detect
circuit
Improper mounting, disconnec-
tion or short-circuit of outdoor unit
temp. sensor TD
Improper mounting,
disconnection or short-circuit of
outdoor unit temp. sensor TE, TS
Improper mounting,
disconnection or short-circuit of
outdoor unit outside air temp.
sensor TO
Air conditioner status
OFF
OFF
OFF
OFF
OFF
Operation continued
(compressor OFF)
OFF
OFF
OFF
OFF
OFF
OFF
OFF
Operation continued
Conditions
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Indicated when an
error is detected
Judgment and action
1. Check power voltages (200±20 VAC).
2. Freezing cycle overload operation
3. Check current detect circuit on the AC side.
1. Failure of compressor (lock, etc.)
• Replace the compressor.
2. Improper compressor wiring (phase loss)
3. Lost-phase operation of power supply
(3-phase models)
1. Operation stops soon when restarted.
• Check IPDU.
2. Lost-phase operation of power supply
Check 3-phase power voltages and wiring.
1. Check freezing cycle (gas leakage).
2. Check low-pressure switch circuit.
3. Check outdoor unit CDB board.
1. Check CDB/IPDU wiring.
2. Freezing cycle overload operation
1. Check phase sequence, reverse phase, and
phase loss.
2. Check outdoor unit boards.
3. Check high-pressure switch.
4. Check high-pressure switch circuit wiring.
1. Check freezing cycle (gas leakage).
2. Failure of electronic expansion valve
3. Check piping sensor (Td).
1. Freezing cycle overload operation
2. Check outdoor unit TE sensor.
3. Check outdoor unit CDB board.
4. Check high-pressure switch and circuit.
1. Position detect error
2. Overcurrent protection circuit operation of
outdoor unit fan driver
3. Outdoor unit fan lock
4. Check outdoor unit CDB board.
1. Operation stops soon when restarted.
• Compressor partial short-circuit
2. Check IPDU for improper wiring.
1. The circuit is activated even after compressor’s
3P connector is disconnected. ...Replace IPDU.
1. Check TD.
2. Check outdoor unit CDB board.
1. Check TE, TS.
2. Check outdoor unit CDB board.
1. Check TO.
2. Check outdoor unit CDB board.
∗
1 DI series is not detected ( SDI 4 ~ 6HP only).
Fan continues rotating in a failure mode detected by outdoor unit because there is no communication between outdoor unit and
follower indoor unit in twin group.
Check code
H01
H02
H03
H06
∗
1
L29
L31*1
P03
P04
P22
P26
P29
F04
F06
F08
Diagnosis function