Cause : Motor parameter incorrect comes when the motor parameters were incorrectly entered while commissioning.

In a Siemens Sinamics drive, fault code F7950 indicates an "Incorrect motor parameter" error. This means the drive detects a mismatch between the parameters configured for the motor and the data stored within the drive itself.

Here's a breakdown of the issue and some troubleshooting steps to help you resolve it:

Possible Causes of F7950 Error:

• Motor Data Mismatch: The most common cause is a discrepancy between the actual motor data (like motor power, voltage, current rating) and the parameters entered during the drive's commissioning process. This mismatch can occur due to:

• Using incorrect motor nameplate data when configuring the drive.
• Data entry errors during commissioning.

• Geared Motors: When using geared motors without DRIVE CLiQ encoders (Siemens proprietary encoder system), this fault can occur due to an incorrect "motor rated power factor" parameter setting.

Troubleshooting Steps:

1. Verify Motor Nameplate Data:

• Locate the motor nameplate, which typically displays the motor's rated power, voltage, current, and other specifications.
• Compare this data with the motor parameters entered during the drive's commissioning process. Ensure all values match exactly.

2. Review Commissioning Settings:

• Refer to the Siemens Sinamics drive manual for your specific model. It should have instructions on how to access and review the motor parameters.
• Double-check all the entered motor data for any typos or inconsistencies.

3. Check for Geared Motor Setting (if applicable):

• If you're using a geared motor without DRIVE CLiQ encoders, consult the Siemens manual for instructions on correcting the "motor rated power factor" parameter setting for this specific configuration.