Mitsubishi Electric PURY-P120, Service Handbook

Page: 243 / 411

[
IX
Troubleshooting ]
- 234 - HWE09130 GB
1. Error Code
Heat exchanger outlet temperature sensor (TH3) fault (Outdoor unit)
Discharge temperature sensor (TH4) fault (Outdoor unit)
Accumulator inlet temperature sensor (TH5) fault (Outdoor unit)
Heat exchanger inlet temperature sensor (TH6) fault (Outdoor unit)
Outside temperature sensor (TH7) fault (Outdoor unit)
2. Error definition and error detection method
Œ
When a short (high temperature intake) or an open (low temperature intake) of the thermistor 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.
Œ
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 minutes when the detected temperature is within the normal
range.
Œ
When a short or an open is detected again (the third detection) after the previous restart of the outdoor unit, the outdoor unit
makes an error stop.
Œ
When a short or an open of the thermistor is detected just before the restart of the outdoor unit, the outdoor unit makes an
error stop, and the error code "5102", "5103", 5104", "5105", "5106"or "5107" will appear.
Œ
During 3-minute antirestart mode, preliminary errors will be displayed on the LED display.
Œ
A short or an open described above is not detected for 10 minutes after the compressor start, during defrost mode, or for 3
minutes after defrost mode.
3. Cause, check method and remedy
<Reference>
5103
5104
5105
5106
5107
Cause Check method and remedy
(1) Thermistor failure Check thermistor resistance.
(2) Pinched lead wire Check for pinched lead wire.
(3) Torn wire coating Check for wire coating.
(4) A pin on the male connector is missing or
contact failure Check connector.
(5) Disconnected wire Check for wire.
(6) Thermistor input circuit failure on the control
board Check the intake temperature of the sensor with the LED
monitor.
When the temperature is far different from the actual temper-
ature, replace the control board.
TH3
TH4
TH5
TH6
TH7
Open detection
-40 C [ -40 F ] and below (130 k and above )
0 C [ 32 F ] and below (698 k and above)
-40 C [ -40 F ] and below (130 k and above)
-40 C [ -40 F ] and below (130 k and above)
-40 °C [ -40 °F ] and below (130 k and above )
Short detection
110 C [230 F ] and above (0.4 k and below )
240 C [464 F ] and above (0.57 k and below )
70 C [158 F ] and above (0.4 k and below )
70 C [158 F ] and above (1.14 k and below )
110 °C [230 °F ] and above (0.4 k and below )