Mitsubishi Electric PUHY-P168, Service Handbook, Page: 291 / 404

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[
IX
Troubleshooting ]
Temperature sensor failure (outdoor unit)
Error Code
Error definition and error
detection method
Cause Check method and remedy
5101 Discharge
(TH11)
(TH12) 1. When a short (high
temperature intake) or
an open (low tempera-
ture intake) of the ther-
mistor is detected (the
first detection), the
outdoor unit stops,
turns to anti-restart
mode for 3 minutes,
and restarts when the
detected temperature
of the thermistor
2. When a short or an
open is detected again
(the second detection)
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.
(1) Thermistor failure Check thermistor resistance.
5105 Piping
(TH5) (2) Pinched lead wire Check for pinched lead wire.
5106 Outdoor air
temperature
(TH6) (3) Torn wire coating Check wire coating.
5107 Piping
(TH7) (4) A pin on the male connec-
tor is missing or contact
failure
Check connector.
(5) Disconnected wire Check for wire.
(6) Thermistor input circuit
failure on the main board
Check the intake temperature of the
sensor with the LED monitor.
When the temperature is far different
from the actual temperature, replace
the control board.
TH11/TH12
TH5
TH6
TH7
Short is detection Open detection
240 C [464 F] and above (0.57 k )
110 C [230 F] and above (0.4k )
110 C [230 F] and above (0.4k )
70 C [158 F] and above (1.14k ) 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 )