This parameter sets the allowable speed difference between the setpoint and actual speed in rpm . Impact: This is primarily used in encoder-based vector control. If the encoder feedback jitters or lags, the deviation might exceed P1744 , triggering the fault.
(identification at standstill). This helps the drive calculate the correct control parameters. Check Mechanical Integrity:
If the system uses closed-loop vector control, a malfunctioning encoder, loose coupling, or damaged feedback cable can report an incorrect speed of "0 RPM" to the drive, tricking it into triggering a stall fault. siemens drive fault code 7902
: The SAC constantly compares the calculated motor speed (derived from the drive's internal mathematical motor model) against the actual speed measured by a physical encoder (if equipped).
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. This parameter sets the allowable speed difference between
Inspect gearboxes, belts, and couplings for visible damage or misalignment. Step 2: Verify Motor Parameterization
Sometimes the motor is not truly stalled but experiences a heavy load spike (e.g., a crusher hitting a rock). If the delay time ( p2178 ) is set too short, the drive trips before the load can break free. (identification at standstill)
: Incorrectly set motor data (voltage, current, or frequency) or missing motor identification (ID) runs.
This parameter sets the allowable speed difference between the setpoint and actual speed in rpm . Impact: This is primarily used in encoder-based vector control. If the encoder feedback jitters or lags, the deviation might exceed P1744 , triggering the fault.
(identification at standstill). This helps the drive calculate the correct control parameters. Check Mechanical Integrity:
If the system uses closed-loop vector control, a malfunctioning encoder, loose coupling, or damaged feedback cable can report an incorrect speed of "0 RPM" to the drive, tricking it into triggering a stall fault.
: The SAC constantly compares the calculated motor speed (derived from the drive's internal mathematical motor model) against the actual speed measured by a physical encoder (if equipped).
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.
Inspect gearboxes, belts, and couplings for visible damage or misalignment. Step 2: Verify Motor Parameterization
Sometimes the motor is not truly stalled but experiences a heavy load spike (e.g., a crusher hitting a rock). If the delay time ( p2178 ) is set too short, the drive trips before the load can break free.
: Incorrectly set motor data (voltage, current, or frequency) or missing motor identification (ID) runs.