Mitsubishi Electric Mr.Slim PKH Series Service Manual page 23

10-4. TROUBLESHOOTING OF PROBLEMS
Phenomena
(1) LED2 on indoor controller board
is off.
OC330C
Note: Refer to the manual of outdoor unit for the detail of remote controller.
Cause
• When LED1 on indoor controller board is also off.
1 Power supply of rated voltage is not supplied to
outdoor unit.
2 Defective outdoor controller circuit board.
3 Power supply of 220~240V is not supplied to indoor
unit.
4 Defective indoor power board.
5 Defective indoor controller board.
(For the separate indoor/outdoor unit power
supply system)
1 Power supply of 220~240V AC is not supplied to
indoor unit.
2 The connectors of the optional replacement kit are
not used.
3 Defective indoor controller board.
4 Defective indoor power board.
• When LED1 on indoor controller board is lit.
1 Mis-setting of refrigerant address for outdoor unit
(There is no unit corresponding to refrigerant address
"0".)
23
Countermeasure
1 Check the voltage of outdoor power
supply terminal block (L, N) or (L
• When AC 220~240V is not detected.
Check the power wiring to outdoor unit
and the breaker.
• When AC 220~240V is detected.
—Check 2 (below).
2 Check the voltage between outdoor
terminal block S1 and S2.
• When AC 220~240V is not detected.
Check the fuse on outdoor controller
circuit board.
Check the wiring connection.
• When AC 220~240V is detected.
—Check 3 (below).
3 Check the voltage between indoor terminal
block S1 and S2.
• When AC 220~240V is not detected.
Check indoor/outdoor unit connecting
wire for mis-wiring.
• When AC 220~240V is detected.
—Check 4 (below).
4 Check voltage output from CN2S on indoor
power board (DC13.1V). Refer to 10-7-2.
• When no voltage is output.
Check the wiring connection.
• When output voltage is between
DC12.5V and DC13.7V.
—Check 5 (below).
5 Check the wiring connection between
indoor controller board and indoor power
board. Check the fuse on indoor controller
board. If no problems are found, indoor
controller board is defective.
1 Check the voltage of indoor power supply
terminal block (L,N).
• When AC220~240V is not detected.
Check the power supply wiring.
• When AC220~240V is detected.
-Check 2 (below).
2 Check that there is no problem in the
method of connecting the connectors.
• When there are problems in the method
of connecting the connectors.
Connect the connector correctly referring
to installation manual of an optional kit.
• When there is no problem in the method
of connecting the connectors.
-Check 3 (below).
3 Check voltage output from CNDK on
indoor controller board.
• When AC220~240V is not detected.
Check the fuse on indoor controller board.
Check the wiring connection between
indoor power supply terminal block and
CND on indoor controller board.
• When AC220~240V is detected.
-Check 4 (below).
4 Check voltage output from CN2S on
indoor power board.
• When no voltage output.
Check the wiring connection between
CNDK on indoor controller board and
CNSK on indoor power board.
If no problem are found, indoor power
board is defective.
• When DC12.5~13.7V is detected.
Check the wiring connection between
CN2S on indoor power board and
CN2D on indoor power board.
If no problem are found, indoor
controller board is defective.
1 Reconfirm the setting of refrigerant
address for outdoor unit
Set the refrigerant address to "0".
(For grouping control system under which
2 or more outdoor units are connected,
set one of the units to "0".)
Set refrigerant address using SW1 (3-6)
on outdoor controller circuit board.
, N).
3