Mitsubishi PUMY-P100YHM Technical & Service Manual page 41

Display
Abnormal point and detecting method
5101
Room temperature thermistor (TH21)
When controller detects short (high
temp.)/open (low temp.) in thermistor
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, <5101> is
displayed. Then, if the thermistor recover
in 3 minutes, it operates normally.
Short: Detected 90
Open: Detected –40
Discharge temperature thermistor (TH4)
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, <5101> is displayed.
For 10 minutes after starting compressor,
for defrosting or for 3 minutes after recover
of defrosting, above-mentioned short/open
are not detected.
Short: 216 or more (1k )
Open: 0 or less (700k )
Note) When outer temperature thermistor
(TH7) is 5 or less on cooling, open
detecting is not determined as abnormality.
Connector (CN20) contact failure
Thermistor wiring disconnection or
half disconnection
Thermistor failure
or more
Detecting circuit failure in the
indoor controller board
or less
Connector (TH4) contact failure
Thermistor wiring disconnection or
half disconnection
Thermistor failure
Multi controller board input circuit
failure
Causes
41
Check points
Check whether the connector
(CN20) 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 (TH4)
in the multi controller board is
connected or not.
Check whether the thermistor wiring
is disconnected or not.
Check the resistance of thermistor;
When the resistance is not below
value, replace the thermistor.
0 ··· about 700k
10 ··· about 410k
20 ··· about 250k
30 ··· about 160k
40 ··· about 104k
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.
1.3: Open
219.4: Short