Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook page 291

[ IX Troubleshooting ]
Temperature sensor failure (outdoor unit)
Error Code
5101 Discharge
(TH11)
(TH12)
5105 Piping
(TH5)
5106 Outdoor air
temperature
(TH6)
5107 Piping
(TH7)
Error definition and error
detection method
1. When a short (high (1) Thermistor failure
temperature intake) or
an open (low tempera-
ture intake) of the ther-
(2) Pinched lead wire
mistor is detected (the
first detection), the
outdoor unit stops,
(3) Torn wire coating
turns to anti-restart
mode for 3 minutes,
and restarts when the
(4) A pin on the male connec-
detected temperature
of the thermistor
2. When a short or an
open is detected again
(5) Disconnected wire
(the second detection)
(6) Thermistor input circuit
after the first restart of
the outdoor unit, the
outdoor unit stops,
turns to anti-restart
mode for 3 minutes,
and restarts in 3 min-
utes when the detect-
ed temperature is
within the normal
range.
3. When a short or an
open is detected again
(the third detection) af-
ter the previous restart
of the outdoor unit, the
outdoor unit makes an
error stop.
4. When a short or an
open of the thermistor
is detected just before
the restart of the out-
door unit, the outdoor
unit makes an error
stop, and the error
code "5101", "5103",
"5104", "5105",
"5106", or "5107" will
appear.
5. During 3-minute anti-
restart mode, prelimi-
nary errors will be dis-
played on the LED
display.
6. A short or an open de-
scribed above is not
detected for 10 min-
utes after the com-
pressor start, during
defrost mode, or for 3
minutes after defrost
mode.
- 282 -
Cause
Check thermistor resistance.
Check for pinched lead wire.
Check wire coating.
Check connector.
tor is missing or contact
failure
Check for wire.
Check the intake temperature of the
failure on the main board sensor with the LED monitor.
When the temperature is far different
from the actual temperature, replace
the control board.
Short is detection
TH11/TH12
240 C [464 F] and above (0.57 k )
TH5 110 C [230 F] and above (0.4k )
TH6 110 C [230 F] and above (0.4k )
TH7 70 C [158 F] and above (1.14k )
Check method and remedy
Open detection
0 C [32 F] and below (643 k )
-40 C [-10 F] and below (130 k )
-40 C [-40 F] and below (130 k )
-40 C [-40 F] and below (130 k )