Siemens Drive Fault Code 7902 Upd [ Quick ]

If the mechanics are fine and the motor simply takes longer to accelerate due to high inertia, you may need to desensitize the stall detection logic.

"Fault 7902," Elias muttered, typing his password into the Siemens TIA Portal software on his laptop. "Communication fault. Drive-to-Drive data exchange failure."

The drive relies on precision electrical characteristics (stator resistance, leakage inductance) to model the rotor's exact movement. Skipping the standstill or rotating data identification tests () after commissioning or changing motor cables triggers false stalls. sinamics drive motor fault 7902 - SiePortal - Siemens

According to Siemens Support , you should follow these steps to resolve the fault: siemens drive fault code 7902

Acceleration times that are too short cause the drive to hit torque limits prematurely. 3. Electrical and Feedback Issues

Set parameter p96 = 1 (Standard commissioning) to apply robust default settings. Conclusion

Verify . Ensure it is set high enough to allow for the breakaway torque required during startup (typically 1.3 to 2 times the rated motor current, depending on the application). Check the torque limit parameters ( p1520 and p1521 ). Step 3: Adjust Stall Detection Thresholds If the mechanics are fine and the motor

Follow this systematic approach. Always lock out and tag out power before touching terminals.

| Cause | Explanation | |-------|-------------| | | KTY84 or PT100 open circuit. Drive interprets infinite resistance as overtemperature. | | Short circuit | Short across sensor leads = zero resistance, also interpreted as fault. | | Wrong sensor type configured | Parameter p0600 (temperature sensor type) set to “no sensor” but sensor wired, or vice versa. | | Sensor connected to wrong terminals | Example: KTY connected to terminals for PTC thermistor. | | Faulty sensor | Internal damage to the thermistor or RTD. | | EMI interference | Noisy signal lines cause erratic resistance readings. |

Start with a clean slate to eliminate misconfigurations. Drive-to-Drive data exchange failure

Lower this value if the drive trips too early during slow-speed operations.

Use embedded motor temperature sensors (PT100/PTC) wired to the drive to catch overheating before a stall occurs.

: Re-run the motor data identification routine (often called "MotID") to ensure the drive accurately understands the electrical characteristics of the motor. Check Mechanical Load

Adjust the drive’s dynamics to match the physical load capabilities. Increase Ramp-Up Time ( p1120p 1120