Siemens alarm F30060: Pre-charge contactor state monitoring

What it means

Feedback monitoring for the pre-charge contactor (ALM, SLM, BLM diode) or line contactor (BLM thyristor) did not return a correct signal within the monitoring time set in p0255[0]. The binary fault value distinguishes switch-in/out timeout, pre-charge contactor opening during pre-charge/infeed operation, and closing while the drive is OFF. This protects against running the infeed without a proven mains connection path.

Likely causes

• pre-charge/line contactor worn, welded or not pulling in
• auxiliary feedback contact or its wiring faulty
• monitoring time p0255[0] shorter than real contactor response
• contactor coil control (digital output/relay) failing

Replacement parts

We supply the following units for this alarm — tested, warranty-backed:

• Line/pre-charge contactor per infeed rating (Siemens 3RT/3TF series)

  infeed · Common cause

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