Mitsubishi Electric PKA-A12LA1 Service Manual page 18

Abnormal point and detection method
Check code
Forced compressor stop
(due to water leakage abnormality)
The unit has a water leakage abnormal-
ity 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 [14°F] 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
PA
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.
Fan motor trouble
Pb
TCH117
Cause
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 dif-
ference at twin, triple or quad-
ruple system
Miswiring of indoor/outdoor
connecting at twin, triple or
quadruple system
Room temperature thermistor/
liquid pipe temperature thermis-
tor detection is defective.
Defective fan motor
Defective indoor controller board
Contact failure of fan motor
connector
18
Countermeasure
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 leadwire 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 dis-
play of outdoor controller board.
- Refer to "9-6-2. DC Fan Motor (fan motor/
indoor controller board)".