Mitsubishi PUMY-P100YHM Technical & Service Manual page 42

Display
Abnormal point and detecting method
5102
Liquid pipe temperature thermistor
(TH22)
When the thermistor detects short/open
during the operation, the operation stops
and the operation changes to protect mode
of restarting in 3 minutes. If the thermistor
does not recover in 3 minutes, the
operation stops due to detecting
abnormality. In this time, <5102> is
displayed. Then, if the thermistor recovers
in 3 minutes, it operates normally.
Short: Detected 90
Open: Detected -40
Low pressure saturation temperature
thermistor (TH6)
When controller detects short/open in
thermistor during the operation, the outdoor
unit stops once and restarts operation in 3
minutes. When the detected temperature is
normal at just before of restarting, the
outdoor unit restarts.
When controller detects short/open in
thermistor at just before of restarting, the
unit stops due to detecting abnormality. In
this time, <5102> is displayed.
For 10 minutes after starting compressor,
heating mode, above-mentioned short/open
are not detected.
Short: 90 or more
Open: -40 or less
1) Connector (CN21) contact failure
2) Thermistor wiring disconnection or
3) Thermistor failure
or more
or less
4) Detecting circuit failure in the
1) Connector (TH6) contact failure
2) Thermistor wiring disconnection or
3) Thermistor failure
4) Multi controller board input circuit
Causes
half disconnection
indoor controller board
half disconnection
failure
42
Check points
Check whether the connector
(CN21) in the indoor controller board
is connected or not.
Check whether the thermistor wiring
is disconnected or not.
Check the resistance of thermistor;
0 ····15k
10 ···9.6k
20 ···6.3k
30 ···4.3k
40 ···3.0k
When there is no problem in above
mentioned , replace the indoor
controller board.
Check whether the connector (TH6)
in the multi controller board is
connected or not.
Check whether the thermistor wiring
is disconnected or not.
Check the resistance of thermistor;
0 ····15k
10 ···9.6k
20 ···6.3k
30 ···4.3k
40 ···3.0k
1 3 4 5 6 7 8 2
on
Set the SW1 to
When the temperature in multi
controller board is not an actual
temperature, replace the multi
controller board.
-42.5: Open
91.9: Short