In the Siemens drive ecosystem, fault code is universally associated with a motor lead or power cable phase failure . Specifically, it indicates that the drive has detected an asymmetry or interruption in the motor’s supply voltage (usually one of the three phases is missing).
To diagnose the code effectively, you must understand how a Siemens drive tracks a stall condition. The system relies on its internal Speed Adaptation Controller (SAC), which functions as a PID regulator.
Motor data identification (motor tuning) has not been performed, or the static/rotating measurements were not completed successfully.
Once the drive registers that the motor has stalled, it does not shut down immediately. It waits for the duration defined in (Motor Stalled Delay). If the condition persists for that entire period, the drive outputs Fault 7902 and trips. siemens drive fault code 7902
If the fault occurs when trying to start a motor that is already spinning (coasting), enable the "Flying Restart" function ( Adjust Fault Limits:
This comprehensive guide breaks down why this fault happens across major Siemens SINAMICS variable frequency drives (VFDs)—including the —and provides an actionable, step-by-step troubleshooting protocol. Anatomy of Fault F07902
: Motor excitation time (increase if fault occurs immediately at start). p1610p 1610 In the Siemens drive ecosystem, fault code is
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.
| Cause | Description | |-------|-------------| | PLC stop | Controller switched to STOP mode, stopped sending cyclic data | | Cable issue | PROFIBUS/PROFINET cable disconnected, damaged, or poorly terminated | | Connector fault | Loose or broken fieldbus connector (especially PROFIBUS 9-pin D-sub) | | Configuration mismatch | Telegram configuration (e.g., telegram type, length) differs between drive and PLC | | Bus overload | Excessive bus cycle time or high bus load causing intermittent telegrams | | Parameter error | p2040 (telegram monitoring time) set too low | | Master failure | Fieldbus master (PLC) power cycle or hardware fault | | Interference | Electromagnetic interference (EMI) on bus cable |
: Limits for stall detection (such as speed or current thresholds) may be set too strictly for the specific application. Acceleration/Deceleration Rates The system relies on its internal Speed Adaptation
This article provides a comprehensive guide to understanding, diagnosing, and resolving the Siemens F07902 motor stalled fault, with a focus on commissioning, parameterization, and motor data identification. 1. What is the Siemens Drive Fault Code 7902?
. "The load is heavy today. The drive is timing out before the motor can overcome the inertia."
To avoid future occurrences of fault code 7902: