Service manual

29
TROUBLESHOOTING
10
1. self-diagnostic function
! When trouble occurs during operation, the unit stops and enters the self-diagnostic mode, and displays the trouble loca-
tion with the timer lamps on the remote controller. All the other lamps are OFF.
@ To activate the self-diagnostic function for service, press the UP and DOWN buttons simultaneously for more than two
seconds during operation with lamp ON.
# The timer lamps show the latest trouble. Trouble data is memorized until the next trouble occurs, even when the breaker
turns OFF. To clear the memory, press the UP and DOWN buttons simultaneously for more than two seconds during the
test run.
$ All buttons except the POWER ON/OFF button are unavailable during the self-diagnostic mode.
% To release the self-diagnostic mode, press the POWER ON/OFF button.
Unit Trouble location
Transmission error
in twin control
Cause
● Wrong wiring between No. 1
and No. 2 units
● Poor connector contact
Measures
● Check dipswitch setting
● Check wiring
Outdoor unit
● Wrong wiring between
indoor/outdoor units
● Outdoor unit abnormality
detection
● Malfunction of outdoor coil
thermistor
● Reversed phase detected
● Check wiring
● Check outdoor unit
● Check outdoor coil thermistor
Unit
No.1
Unit
No.2
Room
temperature
thermistor
(RT1)
● Poor connector contact
● Thermistor malfunction
● Check connector
● Check thermistor
➔ No trouble ➔ replace indoor
controller
board.
Unit
No.1
Unit
No.2
Indoor coil
thermistor
(RT2)
● Poor connector contact
● Thermistor malfunction
● Check connector
● Check thermistor
➔ No trouble ➔ replace indoor
controller
board.
Unit
No.1
Unit
No.2
Drain sensor
(DS)
● Poor connector contact
● Thermistor malfunction
● Check connector
● Check thermistor
➔ No trouble ➔ replace indoor
controller
board.
Unit
No.1
Unit
No.2
Drain
overflow
protection
● Drain pump malfunction
● Drain sensor improperly
mounted
● Check drain pump
● Check drain sensor
➔ No trouble ➔ replace indoor
controller
board.
Unit
No.1
Unit
No.2
Coil frost
or overheat
prevention
● Air passage short cycle
● Air filter clogged
● Indoor fan malfunction
● Remove blockage
● Check air filter
● Check indoor fan
12
11
10
9
8
7
6
5
1
2
3
4
(Indicates that the unit is in self-diagnostic mode)
TEMP.
▲
i
TIMER
w
▲
TIMER
w
▲
29
28
27
26
25
24
23
22
18
19
20
21