Siemens Drive Fault Code 7902 ~upd~ Now

: If the motor fails to stop after an OFF command before being turned back ON, activate the "Flying Restart" function (

This is the "Motor stalled delay time." Increasing this value can prevent "nuisance" trips during brief heavy load periods.

Fault F7902 is triggered during a commissioning or tuning phase known as or Line Data Identification . During this sequence, the Siemens inverter injects specific current pulses into the motor stationary windings (or the incoming supply line) to calculate critical internal variables. These variables include stator resistance, leakage inductance, and rotor time constants. siemens drive fault code 7902

Begin with verifying that the PLC master is actively exchanging cyclic data with the drive’s configured station address. Then check hardware integrity of the bus cable and termination. If the issue persists, match telegram settings exactly between the drive (P0922) and the master’s hardware configuration.

Low-speed, high-torque applications (hoists, mixers, extruders). P1745 is a percentage threshold. The default is 5.0% to 10.0% . If your load causes a larger model error, increase this value. : If the motor fails to stop after

: Ensure the motor is not physically blocked or overloaded.

Understanding what causes the stall detection to trip will help narrow down your physical and software-based checks. If the issue persists, match telegram settings exactly

According to Siemens documentation , F07902 means the . The drive's internal model detects that the calculated speed from the inverter does not match the actual speed of the motor for a sustained period.

The Siemens drive fault 7902 is effectively a "Motor Stalled" protection mechanism. In almost all cases, will resolve the issue. If the error persists, check mechanical components for blockage.

: The motor is stuck at a standstill (below the low-speed threshold set in parameter p2175 ) right from the start.

In technical terms, the drive’s internal motor model compares the expected motor speed (based on the setpoint) against the actual speed feedback (or an estimated value). If the deviation between what should be happening and what is happening exceeds a predefined threshold for a set amount of time, the drive shuts down and raises the F7902 fault to prevent damage to the mechanics, the motor, or the drive itself.