Troubleshooting - Mitsubishi Electric PU-2NJA Technical & Service Manual

TROUBLE SHOOTING
7
7-1. SELF-DIAGNOSTIC FUNCTION
7-1-1. Wired remote controller (1)
! 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
# 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.
TIMER TEMP.
12 12 29 29
11 11 28 28
10 10 27 27
9 9 26 26
8 8 25 25
7 7 24 24
6 6 23 23
5 5 22 22
4 4 21 21
3 3 20 20
2 2 19 19
1 1 18 18
TEMP.
lamp ON.
Unit Trouble location
Wrong wiring between No. 1
Transmission error
and No. 2 units
in twin control
Poor connector contact
Wrong wiring between
indoor/outdoor units
Outdoor unit abnormality
detection
Outdoor unit
Malfunction of outdoor coil
thermistor
Reversed phase detected
Unit
Room
No.1
temperature Poor connector contact
Thermistor malfunction
thermistor
Unit
(RT1)
No.2
Unit
Indoor coil
No.1
Poor connector contact
thermistor
Thermistor malfunction
Unit
(RT2)
No.2
Unit
No.1
Drain sensor Poor connector contact
Thermistor malfunction
(DS)
Unit
No.2
Unit
Drain
No.1 Drain pump malfunction
overflow Drain sensor improperly
Unit mounted
protection
No.2
Unit
Coil frost
Air passage short cycle
No.1
Air filter clogged
or overheat
Indoor fan malfunction
Unit
prevention
No.2
(Indicates that the unit is in self-diagnostic mode)
Cause
12
Measures
Check dip switch setting
Check wiring
Check wiring
Check outdoor unit
Check outdoor coil thermistor
Check connector
}
Check thermistor
No trouble replace indoor
controller
board.
Check connector
}
Check thermistor
No trouble replace indoor
controller
board.
Check connector
}
Check thermistor
No trouble replace indoor
controller
board.
Check drain pump
}
Check drain sensor
No trouble replace indoor
controller
board.
Remove blockage
Check air filter
Check indoor fan