Mitsubishi Electric Mr.SLIM PCA-RP71HA Service Manual page 21

Phenomena
(2)LED2 on indoor controller board
is blinking.
9-4. WHEN WIRED REMOTE CONTROLLER OR INDOOR UNIT MICRO COMPUTER TROUBLES
1. If there is not any other wrong when trouble occurs, emergency operation starts as the indoor controller board switch (SWE)
is set to ON.
During the emergency operation the indoor unit is as follows;
(1) Indoor fan high speed operation
2. When emergency operating for COOL or HEAT, setting of the switch (SWE) on the indoor controller board and outdoor unit
emergency operation are necessary.
3. Check items and notices as the emergency operation
(1) Emergency operation cannot be used as follows;
• When the outdoor unit is something wrong.
• When the indoor fan is something wrong.
• When drain over flow protected operation is detected during self-diagnosis. (Error code : P5)
(2) Emergency operation will be serial operation by the power supply ON/OFF.
ON/OFF or temperature, etc. adjustment is not operated by the remote controller.
(3) Do not operate for a long time as cold air is blown when the outdoor unit starts defrosting operation during heat emer-
gency operation.
(4) Cool emergency operation must be within 10 hours. Other wire, heat exchanger of indoor unit may get frosted.
(5) After completing the emergency operation, return the switch setting, etc. in former state.
(6) Since vane does not work at emergency operation, position the vane slowly by hand.
Cause
• 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.
2 Refrigerant address for outdoor unit is wrong or 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
(2) Drain-up machine operation
21
Note: Refer to the manual of outdoor unit for the detail of remote
controller.
Check indoor/outdoor unit connecting wire
for connection failure.
1 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.
2 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.
34 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