A156 alarm in WEG CFW900 Drive indicates an IGBT Undertemperature. This means the internal components are detecting temperatures near or below their minimum rated operational threshold of -30°C.
Cause:
Alarm of undertemperature measured by the sensors in the IGBTs, rectifier, power and/or control below -30 °C.
- Ambient temperature around the inverter ≤ -30 °C.
Note: The alarm can be disabled by setting C7.5.1.
Remedy:
Verify ambient working temperature. Provide workspace heating if operating in extreme cold. Use parameter C7.5.1 to bypass if desired.
