Mitsubishi Electronics OC366 Air Conditioner User Manual


 
41
Display
Abnormal point and detecting method
Causes
Check points
2502
(Float
switch
model)
Check if drain pump works.
Check drain function.
Check moving part of float switch.
Check the value of resistance with the
float switch ON/OFF.
Change the indoor controller board.
Malfunction of drain pump
Defective drain
Clogged drain pump
Clogged drain pipe
Defective moving part of float switch
Foreign matter on the moving
part of float switch(ex. sludge etc.)
Defective float switch
Defective indoor controller board
Defective driving circuit of drain pump
Defective input circuit of float switch
Check whether the indoor linear
expansion valve leaks or not.
Both of above mentioned ~ and the
indoor linear expansion valve full-closed
failure (leakage) happens
synchronistically.
(Note) Address/Attribute displayed on
the remote controller shows the indoor
unit which is cause of trouble.
Drain pump (DP)
Judge whether the sensor is in the water or
in the air by turning the float switch
ON/OFF.
In the water: Detected that the float switch
is ON for 15 seconds.
In the air:Detected that the float switch is
OFF for 15 seconds.
When the float switch remains to be turned
ON for 3 minutes after detected to be in the
water, the drain pump is judged to be
abnormal and <2502> will be displayed.
*It takes 3 minutes and 15 seconds to detect
abnormality including the time to judge to be
in the water.
The unit continue to detect abnormality
while turned off.
When the conditions below 1, 2 and forced
outdoor unit stop condition are met
1. Detected that
[liquid pipe temperature –
room temperature] -10deg[-18°F] for
30 minutes constantly.
2. Float switch detects to be in the water
for 15 minutes constantly.
*Before Forced outdoor unit stop Condition
is met, the unit always detects - above.
The indoor unit detecting above stops
due to detecting abnormality the outdoor
unit in same refrigerant system
(compressor is inhibited to operate). The
unit which stops due to detecting
abnormality displays <2502>.
Detection timing of forced outdoor unit stop
Constantly detected during unit operation
and stop
Releasing of forced outdoor unit stop
Reset power supply of both abnormal
indoor unit and its outdoor unit in same
refrigerant system. Forced outdoor unit
stop cannot be released by remote
controller OFF.
NOTE )
Above-mentioned ~ and ~ are
detected independently.
2503
4100
Drain sensor (THd, DS)
When the drain sensor detects short/open
while the operation.
Compressor overcurrent interruption
(When compressor locked)
Abnormal if overcurrent of DC bus or
compressor is detected within 30 seconds after
compressor starts operating.
Over current : 27.5A
Connector (CN31) contact failure
(insertion failure)
Thermistor wiring disconnection or half
disconnection
Thermistor defective
Indoor controller board (detecting circuit)
failure
Stop valve is closed.
Decrease of power supply voltage
Looseness, disconnection or converse of
compressor wiring connection
Defective compressor
Defective outdoor power board
Check whether the indoor controller
board connector (CN31) is
disconnected or not.
Check whether the thermistor wiring is
disconnected or not.
Check the resistance of thermistor.
If abnormality is not found in the
method of the above-mentioned from
to , it is defective of the indoor
controller board.
Open stop valve.
Check facility of power supply.
Correct the wiring (U·V·W phase) to
compressor.
Check compressor.
Replace outdoor power circuit board.
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