Siemens alarm F30004: Power unit: overtemperature heat sink AC inverter
SINAMICS S120 drive fault · SINAMICS S120
What it means
Heat-sink temperature of the power unit exceeded the permissible limit value (fault value = temperature in 0.01 C).
Likely causes
- fan failure or blocked airflow/filters
- ambient temperature too high
- pulse frequency raised above rated
- sustained overload
- failed heatsink thermistor reporting false high temperature
Triage note: Verify with r0037[0] heatsink temperature at cold start; a hot reading on a cold module points to the sensor, requiring module replacement.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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6SL3162-… / module-specific fan kit
cooling fan assembly · Primary suspect
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6SL3120-… / 6SL3210-…
power unit (if cold-fault persists = sensor/power stage) · Common cause
Need the part urgently?
Send us alarm F30004 with your machine details — typical RFQ turnaround is 24–48h.