Troubleshooting Of Problems - Mitsubishi Electric Mr.SLIM SFZ Series Technical & Service Manual

[ IX TROUBLESHOOTING ]

4. Troubleshooting of problems

Phenomena
(1) LED2 on indoor controller board is
off.
(2) LED2 on indoor controller board is
blinking.
HWE1909A
Cause
• When LED1 on indoor controller board is also off.
Power supply of rated voltage is not supplied to
1
outdoor unit.
2 Defective outdoor controller circuit board
3
Power supply of 220~240V is not supplied to
indoor unit.
4 Defective indoor controller board
• When LED1 on indoor controller board is also
blinking.
Connection failure of indoor/outdoor unit
connecting wire
• When LED1 is lit.
1 Mis-wiring of remote controller wires
Under twin triple indoor unit system, 2 or more
indoor units are wired together.
Refrigerant address for outdoor unit is wrong or
2
not set.
Under grouping control system, there are some
units whose refrigerant address is 0.
3 Short-cut of remote controller wires
4 Defective remote controller
- 40 -
Note: Refer to the manual of outdoor unit for the detail of remote
controller.
Check the voltage of outdoor power
1
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 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
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 Check the fuse on indoor controller board.
Check the wiring connection.
If no problem are found, indoor controller
board is defective.
Check indoor/outdoor unit connecting wire
for connection failure.
1 Check the connection of remote controller
wires in case of twin triple indoor unit
system. When 2 or more indoor units are
wired in one refrigerant system, connect
remote controller wires to one of those
units.
Check the setting of refrigerant address
2
in case of grouping control system.
If there are some units whose refrigerant
addresses are 0 in one group, set one of
the units to 0 using SW1 (3-6) on outdoor
controller circuit board.
3 4 Remove remote controller wires and
check LED2 on indoor controller board.
• When LED2 is blinking, check the
short-cut of remote controller wires.
• When LED2 is lit, connect remote
controller wires again and:
if LED2 is blinking, remote controller
is defective; if LED2 is lit, connection
failure of remote controller terminal
block etc. has returned to normal.
Countermeasure
, N).
3
(below).
2
(below).
3
(below).
4
GB