WEG CFW500 fault F0051: IGBTs overtemperature
The power module temperature, measured by its internal sensor and shown in P0030, reached the overtemperature trip level for the model (between 80 °C and 123 °C depending on frame and rating). Alarm A0050 warns 5 °C below the trip level, and the inverter then reduces the switching frequency to 2500 Hz unless that is disabled in P0397.
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When it happens
- During sustained high output current
- In a hot cabinet or high ambient temperature
- When the cooling fan or heatsink airflow is impaired
Likely causes and checks
1High ambient temperature around the inverter (above 50 °C) with high output current
- Points to it
- Trips on hot days or under heavy load; A0050 appears first.
- Check
- Measure the air temperature around the inverter and the output current (P0003).
2Blocked or defective fan
- Points to it
- Fan does not run or runs slowly when the inverter is hot.
- Check
- Check the fan runs freely; on frames C, D and E the fan starts above 60 °C in P0030 with the inverter enabled.
3Heatsink too dirty, preventing airflow
- Points to it
- Dust or fibres on the heatsink; temperature climbs faster than before.
- Check
- With power isolated, inspect and clean the heatsink.
Telling it apart
- Read P0054 (IGBT temperature at the last fault) and P0051 (current): high temperature with modest current points to cooling; high temperature with high current points to load.
- A0050 is the warning at 5 °C below the F0051 level; repeated A0050 alarms before the trip show a cooling margin problem.
Relevant parameters
| Parameter | Name | Why it matters |
|---|---|---|
| P0030 | Power module temperature | Compared with the F0051 and A0050 levels for the model. |
| P0297 | Switching frequency | Reduced automatically to 2500 Hz on A0050. |
| P0397 | Control configuration | Bit 3 enables the switching frequency reduction on A0050; WEG warns against changing it without WEG direction. |
Evidence to collect
- Fault history P0050–P0055, especially P0054 (IGBT temperature) and P0051 (current)
- P0030 trend and any A0050 alarms
- Ambient temperature in the cabinet
- Fan operation and heatsink condition
- Switching frequency P0297
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