Mitsubishi Electric PEAD Series Service Manual page 34

TROUBLESHOOTING
Error Code Abnormal point and detection method
Indoor/outdoor unit communication
error (Signal receiving error)
1 Abnormal if indoor controller board
cannot receive any signal normally for
six minutes after turning the power on.
2 Abnormal if indoor controller board
cannot receive any signal normally for
three minutes.
3 Consider the unit as abnormal under the
E6
following condition: When two or more
indoor units are connected to an outdoor
unit, indoor controller board cannot
receive a signal for three 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
times continuously though indoor controller
E7
board has transmitted "0".
Indoor controller board
Abnormal if data cannot be read normally
Fb from the nonvolatile memory of the indoor
controller board.
Remote controller control board
1 Abnormal if data cannot be read
normally from the nonvolatile memory
of the remote controller control board.
E1
(Error code: E1)
or
E2
2 Abnormal if the clock function of remote
controller cannot be operated normally.
(Error code: E2)
Water leakage
This detection is performed during the
operation (stop, heating, fan, or error stop
mode etc.) other than cooling and dry.
1 When a) and b) are found, water
leakage occurs.
a) Pipe <liquid> temperature - inlet
b) When drain float switch is detected to
be soaked in the water for 15 minutes
or more.
* When drain float switch is detected to
be NOT soaked in the water, each
counting of a) and b) is cleared.
*When this error is detected, the error
PA
will not be reset until the main power is
(2500)
reset.
HWE16080
Cause
1 Contact failure, short circuit or,
mis-wiring (converse wiring) of
indoor/outdoor unit connecting
wire
2 Defective transmitting receiving
circuit of indoor controller
board
3 Defective transmitting receiving
circuit of indoor controller
board
4 Noise has entered into indoor/
outdoor unit connecting wire.
1 Defective transmitting receiving
circuit of indoor controller
board
2 Noise has entered into power
supply.
3 Noise has entered into outdoor
control wire.
1 Defective indoor controller
board
1 Defective remote controller
1 Mis-piping of extension pipes
(When connected with multiple
units)
2 Mis-wiring of indoor/outdoor
unit connecting wire (When
connected with multiple units)
3 Detection failure of the indoor
unit inlet/pipe <liquid>
thermistor
4 Drain pump failure
5 Drainage failure
Clogged drain pump
Clogged drain pipe
6 Drain float switch failure
Drain float switch is detected to
be soaked in the water (ON
status) due to the operation
failure of the moving parts.
Contact failure of drain float
switch connector
(Loose connector)
34
Countermeasure
* Check LED display on the outdoor control
circuit board. (Connect A-control service tool,
Refer to EA-EC item of the service manual of
outdoor unit if LED displays EA-EC.
1 Check disconnection or looseness of
indoor/outdoor unit connecting wire of
indoor unit or outdoor unit.
Check all the units in case of twin triple
indoor unit system.
2-4 Turn the power off, and on again to
check. If abnormality generates again,
replace indoor controller board or
outdoor controller circuit board.
* Other indoor controller board may have
defect in case of twin triple indoor unit
system.
1-3 Turn the power off, and on again to
check. If abnormality generates again,
replace indoor controller board.
1 Replace indoor controller board.
1 Replace remote controller.
1 Check the extension pipes for mis-piping.
2 Check the Indoor/outdoor unit connecting
wire for mis-wiring.
3 Check room temperature display on remote
controller and indoor pipe <liquid>
temperature. (Refer to the countermeasure
on P2.)
4 Check if drain-up machine works.
5 Check drain function.
6 Check drain float switch. (Refer to the
countermeasure on P4 and P5.)