Mitsubishi Electric PURY-P72 Service Handbook page 215

[ IX Troubleshooting ]
1. Error Code
4230 (THMU-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 100°C [212°F]
P96, P120 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 (THMU-A)" under part [4] Troubleshooting Principal Parts for error codes related to the
inverter.(page 293)
HWE0803A
TOH
90°C [194°F]
Refer to IX [4] -7- (2) [6].(page 296)
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 296)
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 andP120 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.
Check method and remedy
- 206 - GB