Siemens Drive Fault Code 7902 ((link))

These are the most common sources of F7902 faults and are often the result of incomplete commissioning or incorrect parameter settings.

Always maintain up-to-date parameter backups via an SD card or Siemens TIA Portal project files so you can quickly restore known working baselines if parameters are corrupted. To help diagnose this further, please tell me:

at start, or only when you add a load? sinamics drive motor fault 7902 - SiePortal - Siemens

When a Siemens drive encounters code F07902, the inside the firmware has flagged a critical discrepancy. The drive's internal calculator compares the expected speed model against either actual encoder feedback or its internal encoderless calculation matrix. If the motor is running at full torque or current limit and its speed drops significantly below the setpoint for longer than a specified delay time, the drive shuts down via an OFF2 (coast to stop) command to protect the motor from burning out. F07900 vs. F07902: What is the Difference? siemens drive fault code 7902

If the application requires it, activate flying restart by setting . 6. Perform a Motor ID Run

: A faulty or incorrectly configured speed sensor/encoder can provide the wrong feedback to the speed controller. Current Limits : The set current limits ( p0640p 0640

Temporarily set p2175 = 0 to disable the blocked motor fault to test if it's a torque limit issue. B. Encoder vs. Sensorless Vector Control These are the most common sources of F7902

Siemens Drive Fault Code 7902 is a sophisticated safety feature designed to protect machinery from damage due to unexpected stops. While the initial appearance of the fault may suggest a major mechanical seizure, the root cause is often a simple fix: a stuck brake, a misconfigured encoder, or a delay time set too strictly.

If a motor encoder is used and the fault persists after a motor ID, a physical check of the encoder is required. Verify the following:

When this fault occurs, the drive's internal intelligence has failed to successfully measure and map the electrical characteristics of the connected motor or power grid. sinamics drive motor fault 7902 - SiePortal -

Unlike fault 7900 (Motor Blocked), which usually occurs at very low speeds, typically triggers when the motor enters a current limit above a specific speed threshold. The drive monitors the deviation between the speed setpoint and the actual speed feedback (or estimated speed in encoderless mode). Primary Causes & Parameters

Yes, by setting p0600 = 0 (disable temperature monitoring). However, this removes overtemperature protection – .

When Fault 7902 appears, follow this structured approach:

is a protective response to either genuine motor overheating or a faulty temperature sensing circuit. By following a logical diagnostic path—checking actual motor temperature, inspecting wiring, verifying parameters, and analyzing historical data—most instances can be resolved in under 30 minutes.

: The default delay time for stall detection is too short for high-inertia loads. siemens drive fault 7902 - Click2Electro