Troubleshooting By Inferior Phenomena - Mitsubishi Electric SEZ Series Technical & Service Manual

[ VII TROUBLESHOOTING ]

5. TROUBLESHOOTING BY INFERIOR PHENOMENA

Phenomena
(1)LED2 on indoor controller board
is off.
(2)LED2 on indoor controller board
is blinking.
HWE21010
Cause
• When LED1 on indoor controller board is also off.
Power supply of rated voltage is not supplied to out-
door unit.
Defective outdoor controller circuit board
Power supply of 220~240V is not supplied to indoor
unit.
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.
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 not
set.
Under grouping control system, there are some units
whose refrigerant address is 0.
Short-cut of remote controller wires
Defective remote controller
- 40 -
Note: Refer to the manual of outdoor unit for the detail of remote
controller.
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
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
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
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.
Check the connection of remote con-
troller 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
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.
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).
(below).
(below).
GB