Mitsubishi Electric SLZ Series Technical & Service Manual page 19

Check code
Abnormal point and detection method
Forced compressor stop
(due to water leakage abnormality)
1 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 14°F [−10°C] for a total of 30
minutes. (When the drain float switch
is detected to be NOT soaked in the
water, the detection record of a) and b)
will be cleared.)
PA
b) Drain float switch detects to be in the
water for more than 15 minutes.
Note: Once the water leakage abnormal-
ity is detected, abnormality state
will not be released until the main
power is reset.
Fan motor trouble
PB(Pb)
TCH118
Cause
1 Drain pump trouble
2 Drain defective
· 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
being clogged
Extension piping connection
difference at twin, triple or
quadruple system
Miswiring of indoor/outdoor
connecting at twin, triple,
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
19
Countermeasure
1 Check the drain pump.
2 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 cleanliness.
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 "8-7-2. DC Fan Motor (Fan
Motor/Indoor Controller Board".