Mitsubishi Electric PURY-P72 Service Handbook page 233

[ IX Troubleshooting ]
4230
1. Error Code
4230 (TKMU-A)
Heatsink overheat protection
2. Error definition and error detection method
When the heat sink temperature (THHS) remains at or above TOH is detected.
Model
P72 model
P96, P120, P144 models
3. Cause, check method and remedy
Cause
(1) Fan board failure
(2) Outdoor unit fan failure
(3) Air passage blockage
(4) THHS failure
Refer to section -7- "Inverter (TKMU-A)" under part [4] Troubleshooting Principal Parts for error codes related to the
inverter.(page 310)
HWE1116D
TOH
100°C [212°F]
90°C [194°F]
Refer to IX [4] -7- (2) [6], [7], [8].(page 314)
Check the outdoor unit fan operation.
If any problem is found with the fan operation, check the fan motor. ->Refer to
IX [4] -7- (2) [5].(page 314)
Check that the heat sink cooling air passage is not blocked
P72 model
1) Check for proper installation of the INV board IGBT. (Check for proper instal-
lation of the IGBT heatsink.)
2) Check for proper installation of the INV board IGBT.
->If an abnormal value appears, replace the INV board.
P96, P120, P144 models
3) Check the THHS sensor reading on the LED monitor.
->If an abnormal value appears, check the sensor resistance, and replace the
sensor as necessary.
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Check method and remedy
GB