Mitsubishi Electric Mr. SLIM PKA Series Service Manual page 22

Abnormal point and detection method
Check code
Forced compressor stop
(due to water leakage abnormality)
1 The unit has a water leakage abnor-
mality 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: for a total of
30 minutes. (When the drain sensor
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.
PA
Note:
Once the water leakage abnormality is
detected, abnormality state will not be
released until the main power is reset.
Fan motor trouble
Pb
TCH069A
Cause
1 Drain pump trouble
2 Drain defective
· Drain pump clogging
· Drain pipe clogging
3 Open circuit of float switch
4 Contact failure of float switch
connector
5 Dew condensation on float
switch
· Drain water descends along
lead wire.
· Drain water is waving due to
filter clogging.
6 Extension piping connection
difference at twin, triple or
quadruple system
7 Miswiring of indoor/ outdoor
connecting at twin, triple or
quadruple system
8 Room temperature thermistor/
liquid pipe temperature
thermistor detection is
defective.
1 Defective fan motor
2 Defective indoor controller board
22
Countermeasure
1 Check the drain pump.
2 Check whether water can be drained.
3 Check the resistance of the float switch.
4 Check the connector contact failure.
5 Check the float switch leadwire mounted.
Check the filter clogging.
6 Check the piping connection.
7 Check the indoor/ outdoor connecting wires.
8 Check the room temperature display of
remote controller.
Check the indoor liquid pipe temperature
display of outdoor controller board.
12 Refer to "9-6-2. DC Fan Motor (fan motor/
indoor controller board)".