Mitsubishi Electric PUMY-P125VMA1 Technical & Service Manual page 46

From the preceding page.
Display
Meaning and detecting method
4250
5101
Suction temperature thermistor (TH21)
abnormality
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 3minutes. If the
thermistor does not recover in 3minutes,
the operation stops abnormally. In this
time, <5101> is displayed. Then, if the
thermistor recover in 3minutes, it operates
normally.
Short: Detected 90; or more
Open: Detected —40; or less
Discharge temperature thermistor (TH1)
abnormality
1
When controller detects short/open in
thermistor during the operation, the
outdoor unit stops once and restarts
operation in 3minutes. When the detected
temperature is normal at just before of
restarting, the outdoor unit restarts.
2
When controller detects short/open in
thermistor at just before of restarting, the
unit stops abnormally. In this time, <5101>
is displayed.
3
While the compressor is protected not to
restart in 3minutes, the unit is delayed
abnormal stop. Then, the outdoor unit
address No. and check delay code
<1202> blinks alternately on the 4 digit
digital display.
SW1 setting
on
4 For 10 minutes after starting compressor,
for defrosting or for 3minutes 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
(TH6) is 5; or less on cooling, open
detecting is not determined as
abnormality.
PUMY-P125VMA
1) Stop valve of outdoor unit is closed.
2) Decrase of power supply voltage
3) Looseness, disconnection or converse
4) Defective fan of indoor/outdoor units
5) Short cycle of indoor/outdoor units
6) Defective input circuit of outdoor
7) Defective compressor
1) Connector (CN20) contact failure
2) Thermistor wiring disconnection or
half disconnection
3) Thermistor failure
4) Detecting circuit failure in the
indoor controller board
1) Connector (TH1) contact failure
2) Thermistor wiring disconnection or
half disconnection
3) Thermistor failure
1 3 4 5 6 7 8 2
4) Multi controller board input circuit
failure
Causes
PUMY-125VMA
of compressor wiring connection
controller board
46
Check points
8
When not applying from 4 to 7, it
applies to 9) and 10).
Check the compressor.
In case of 10), recheck the compressor
again after 12 hours with former power
supply.
1
1
Open stop valve.
2
Check facility of power supply.
3
Correct the wiring (U•V•W phase) to
compressor.
4
Check indoor/outdoor fan.
5
Solve short cycle.
6
Replace outdoor controller board.
7
Check compressor.
1
Check whether the connector
(CN20) in the indoor controller board
is connected or not.
2
Check whether the thermistor wiring
is disconnected or not.
3 Check the resistance of thermistor;
0;···15k'
10;···9.6k'
20;···6.3k'
30;···4.3k'
40;···3.0k'
4
When there is no problem in above
mentioned 123,replace the indoor
controller board.
1
Check whether the connector (TH1)
in the multi controller board is
connected or not.
2
Check whether the thermistor wiring
is disconnected or not.
3
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
4
When the temperature in multi
controller board is not an actual
temperature, replace the multi
controller board.
-99.9: Open
999.9: Short