The most straightforward reason is a heavy mechanical load that exceeds the torque capacity of the motor or drive combination. If a mechanical brake does not release properly, or if downstream equipment (such as conveyors, pumps, or mixers) is jammed, the motor will lag behind its frequency command. 2. Missing or Incomplete Motor Commissioning
typically corresponds to: "PROFIBUS: Cyclic connection failed" (or PROFINET equivalent, depending on the telegram type)
Tighten all terminal connections at both the inverter output and the motor terminal box.
: Verify and potentially increase the stall detection time or torque limits if the application involves high-inertia loads. Review Ramp Times siemens drive fault code 7902
Check the operation of the mechanical holding brake. Ensure it receives the proper voltage signal to release when the drive starts. Step 2: Review Output and Power Cabling Electrical discontinuity mimics a mechanical stall.
Use embedded motor temperature sensors (PT100/PTC) wired to the drive to catch overheating before a stall occurs.
If you must run a rotating identification ( p1910 = 2 ), uncouple the motor from the gearbox or mechanical load if possible. High load inertia or static friction during a tuning cycle will cause the identification algorithm to fail, generating an F7902 error. The most straightforward reason is a heavy mechanical
Elias shook his head. "It’s an S120 multi-drive system, Marcus. Look at the cabinet. One line supply module, but two motor modules. There’s a main drive for the flywheel, and a secondary servo for the feeder that pushes the metal sheets in. They talk to each other via a telegram to synchronize the speed. If the feeder drive doesn't report its position to the main drive, the main drive locks out to prevent crushing the tooling."
Increase the acceleration time to give the motor more time to reach speed without hitting the stall threshold. If you are using a SINAMICS G120XA
Always cross-reference physical temperature with sensor reading. Ensure it receives the proper voltage signal to
The Siemens drive fault code indicates that the drive has detected a stalled motor condition . This critical safety mechanism trips the frequency converter to prevent catastrophic hardware failure, high-current overheating, or mechanical destruction. It primarily appears across the Siemens SINAMICS family, including the G120, G120C, G120XA, and S120 high-performance drives .
Marcus looked at the row of black modules in the cabinet. "Okay, so we check the second drive."