Siemens Drive Fault Code 7902 | Free Forever

The Siemens drive fault code F7902 (or 7902) Motor Stalled (or "Motor out of step"). This fault occurs when the drive detects that the motor is not rotating despite a torque or current being applied, or it has lost synchronism with the drive's output frequency. Common Causes Mechanical Overload:

Thresholds: If the motor is fine but the load is heavy, you might need to increase the current setpoint (p1610) or the stall delay time (p2178). siemens drive fault code 7902

Check Cable Connections: Verify U-V-W connections for the motor. The Siemens drive fault code F7902 (or 7902)

Siemens drive fault code 7902 typically indicates a "Drive: Communication board (CB) link error" or a loss of communication via the PROFINET/PROFIBUS interface. Network Cable Issues: The Ethernet cable (PROFINET) or

Common Causes

  1. Network Cable Issues: The Ethernet cable (PROFINET) or PROFIBUS cable is disconnected, broken, or loose.
  2. Connector Issues: The RJ45 connector is not clicked in properly, or the PROFIBUS connector is not terminated correctly (missing or incorrect termination resistors).
  3. PLC Stop: The PLC controlling the drive has stopped running or has been powered off.
  4. Network Congestion/Noise: High electromagnetic interference (EMI) or a faulty network switch is causing packet loss.
  5. Configuration Mismatch: The telegram configuration in the PLC does not match the configuration in the drive parameters.

5. Quick fix (if safe)

  • Set p2163 (overspeed delay) to 10–20 ms
  • Or disable overspeed monitoring temporarily with p2100[0] = 7902, p2101[0] = 0 (only for testing — do not leave disabled)

The Siemens drive fault code F7902 (or 7902) Motor Stalled (or "Motor out of step"). This fault occurs when the drive detects that the motor is not rotating despite a torque or current being applied, or it has lost synchronism with the drive's output frequency. Common Causes Mechanical Overload:

Thresholds: If the motor is fine but the load is heavy, you might need to increase the current setpoint (p1610) or the stall delay time (p2178).

Check Cable Connections: Verify U-V-W connections for the motor.

Siemens drive fault code 7902 typically indicates a "Drive: Communication board (CB) link error" or a loss of communication via the PROFINET/PROFIBUS interface.

Common Causes

  1. Network Cable Issues: The Ethernet cable (PROFINET) or PROFIBUS cable is disconnected, broken, or loose.
  2. Connector Issues: The RJ45 connector is not clicked in properly, or the PROFIBUS connector is not terminated correctly (missing or incorrect termination resistors).
  3. PLC Stop: The PLC controlling the drive has stopped running or has been powered off.
  4. Network Congestion/Noise: High electromagnetic interference (EMI) or a faulty network switch is causing packet loss.
  5. Configuration Mismatch: The telegram configuration in the PLC does not match the configuration in the drive parameters.

5. Quick fix (if safe)