Mitsubishi Electric SLZ Series Technical & Service Manual page 20

Check code
Abnormal point and detection method
Forced compressor stop
(due to water leakage abnormality)
1 When the intake temperature subtracted
from liquid pipe temperature is less than
-10°C, drain sensor detects whether it is
soaked in the water or not at the interval
of 90 seconds. (Drain pump will start
operating when the drain sensor detects
to be soaked in the water.)
2 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 drain sensor detects to be
soaked in the water 10 times in a row.
b) The intake temperature subtracted
PA
from liquid pipe temperature is
(2502)
detected to be less than -10°C for a
(2500)
total of 30 minutes.
(When the drain sensor detects to
be NOT soaked in the water, the
detection record of a) and b) will be
cleared.)
The drain sensor detection is performed
in operations other than cooling. (When
the unit stops operating, during heat
ing or fan operation, when the unit stops
because of some abnormalities)
* Once the water leakage abnormality is
detected, abnormality state will not be
released until the main power is reset.
OCH564
Cause
1 Drain pump trouble
2 Drain defective
· Drain pump clogging
· Drain pipe clogging
Open circuit of drain sensor
side heater
Contact failure of drain sensor
connector
Dew condensation on drain
sensor
· Drain water trickles along lead
wire
· Drain water waving due to filter
clogging
Extension piping connection
difference at twin, triple,
quadruple system
Miswiring of indoor/outdoor
connecting at twin, triple,
quadruple system
Room temperature thermistor/
liquid pipe temperature
themistor detection is defective.
20
Countermeasure
1 Check the drain pump.
2 Please check whether water can be drained.
Check the resistance of the drain sensor side
heater.
Check the connector contact failure.
Check the drain sensor 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.