7902: Siemens Drive Fault Code

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If there is an output contactor installed between the drive and the motor, ensure that it is commanded to close before the drive attempts the identification run. If the contactor remains open, the drive looks into an open circuit and triggers F7902.

Ensure no mechanical binding or seized bearings are preventing rotation. siemens drive fault code 7902

If the drive is in closed-loop control (p1300 = 21) and the encoder signal is faulty, the drive may get conflicting data.

Resolving this code involves checking the internal counters, performing the necessary physical maintenance, and resetting the drive parameters using tools like STARTER, Startdrive, or the Basic Operator Panel (BOP-2) / Intelligent Operator Panel (IOP-2). 1. Verify the Active Fault or Alarm user wants a long article about Siemens drive

When operating in sensorless vector control (SLVC) mode without a physical encoder, the drive relies on mathematical estimation to determine rotor position. At very low frequencies (typically below 5 Hz), this estimation becomes less accurate. If the load changes sharply in this zone, the drive can lose orientation and flag a stall. 6. Defective Feedback Loop or Hardware

To bypass F7902 altogether during future system startups, embed these professional practices into your commissioning sequence: search results show several relevant pages

If running in vector control mode, execute a new motor data identification routine ( or p1910 ) to allow the drive to map the motor’s electrical characteristics accurately. Prevention and Best Practices