Mitsubishi Electric Mr.Slim PCA-M35KA2 Service Manual page 26

Check Code Abnormal point and detection method
Indoor/outdoor unit communication
error (Signal receiving error)
Abnormal if indoor controller board can-
not receive any signal normally for 6
minutes after turning the power on.
Abnormal if indoor controller board can-
not receive any signal normally for 3
minutes.
E6
Consider the unit abnormal under the
following condition: When 2 or more
indoor units are connected to an out-
door unit, indoor controller board can-
not receive a signal for 3 minutes from
outdoor controller circuit board, a signal
which allows outdoor controller circuit
board to transmit signals.
Indoor/outdoor unit communication
error (Transmitting error)
Abnormal if "1" receiving is detected 30
E7
times continuously though indoor controller
board has transmitted "0".
Indoor controller board
Abnormal if data cannot be read normally
FB
(Fb)* from the nonvolatile memory of the indoor
controller board.
Remote controller control board
Abnormal if data cannot be read nor-
mally from the nonvolatile memory of
E1
the remote controller control board.
or
(Check code: E1)
E2
Abnormal if the clock function of remote
controller cannot be operated normally.
(Check code: E2)
Forced compressor stop
(due to water leakage abnormality)
The unit has a water leakage
abnormality when the following
conditions, a) and b), are satisfied
while the above-mentioned detection is
performed.
a) The intake temperature subtracted
with liquid pipe temperature detects
to be less than −10˚C for a total of
30 minutes. (When the drain sensor
PA is detected to be NOT soaked in the
water, the detection record of a) and b)
will be cleared.)
b) Drain float switch detects to be in the
water for more than 15 minutes.
Note:
Once the water leakage abnormality is
detected, abnormality state will not be
released until the main power is reset.
Indoor Fan motor trouble
PB
(Pb)
Abnormal refrigerant circuit
During Cool, Dry, or Auto Cool operation,
the following conditions are regarded as
failures when detected for 1 second.
a) The compressor continues to run for 30
or more seconds.
PL b) The liquid pipe temperature or the
condenser/evaporator temperature is
75°C or more.
These detected errors will not be
cancelled until the power source is
reset.
OCH752
Cause
Contact failure, short circuit or,
miswiring (reverse wiring) of
indoor/outdoor unit connecting
wire
Defective transmitting receiv-
ing circuit of indoor controller
board
Defective transmitting receiv-
ing circuit of indoor controller
board
Noise has entered into indoor/
outdoor unit connecting wire.
Defective transmitting receiving
circuit of indoor controller board
Noise has entered into power
supply.
Noise has entered into outdoor
control wire.
Defective indoor controller
board
Defective remote controller
Drain pump trouble
Defective drainage
· Drain pump clogging
· Drain pipe clogging
Open circuit of float switch
Contact failure of float switch
connector
Dew condensation on float
switch
· Drain water trickles down
lead wire.
· Drain water ripples due to
filter clogging.
Extension piping connection
difference at twin, triple or
quadruple system
Miswiring of indoor/outdoor
connecting at twin, triple or
quadruple system
Room temperature thermistor/
liquid pipe temperature
thermistor detection is
defective.
1 Defective fan motor
2 Defective indoor controller board
3 Contact failure of fan motor
connector
Abnormal operation of 4-way
valve
Disconnection of or leakage in
refrigerant pipes
Air into refrigerant piping
Abnormal operation (no rotation)
of indoor fan
· Defective fan motor.
· Defective indoor control board.
Defective refrigerant circuit
(clogging)
26
Judgment and action
Check LED display on the outdoor control
circuit board. (Connect A-control service
tool, PAC-SK52ST.) Refer to outdoor unit ser-
vice manual.
Check disconnection or looseness of indoor/
outdoor unit connecting wire of indoor unit or
outdoor unit.
Check all the units in the case of twin triple
indoor unit system.
– Turn the power off, and on again to
check. If abnormality occurs again,
replace indoor controller board or outdoor
controller circuit board.
Note:
Other indoor controller board may have defect
in the case of twin triple indoor unit system.
– Turn the power off, and on again to
check. If abnormality occurs again,
replace indoor controller board.
Replace indoor controller board.
* The check code in the parenthesis indicates
PAR-4xMAA ("x" represents 0 or later).
Replace remote controller.
Check the drain pump.
Check whether water can be drained.
Check the resistance of the float switch.
Check the connector contact failure.
Check the float switch lead wire mounted.
Check the filter clogging.
Check the piping connection.
Check the indoor/outdoor connecting wires.
Check the room temperature display of
remote controller.
Check the indoor liquid pipe temperature
display of outdoor controller board.
1-3 Refer to "9-6-2. DC Fan Motor (fan motor/
indoor controller board)".
When this error occurs, be sure to replace
the 4-way valve.
Check refrigerant pipes for disconnection or
leakage.
After the recovery of refrigerant, vacuum dry
the whole refrigerant circuit.
Refer to section "9-6-2. DC Fan motor (fan
motor/indoor controller circuit board)".
Check refrigerant circuit for operation.
To avoid entry of moisture or air into
refrigerant circuit which could cause
abnormal high pressure, purge air in
refrigerant circuit or replace refrigerant.