Cause : Supply mains undervoltage comes when the measured DC bus voltage is lower than the rated voltage of the Supply Mains (Mains voltage).

"USF" fault in Schneider ATV610 drive indicate mains supply undervoltage condition. This means the voltage supplied to the drive has fallen below the acceptable threshold, which can affect performance and operation.

Follow These Steps to Correct "USF Supply mains undervoltage" Fault:

1. Immediate Actions:

   • Stop Operation: Immediately stop the drive to prevent any potential damage.
   • Disconnect Power: Safely disconnect the power supply to the drive.

2. Check Supply Voltage:

   • Measure Voltage: Use a multimeter to measure the incoming supply voltage and ensure it meets the drive’s specifications.
   • Check for Fluctuations: Look for any fluctuations or drops in voltage during operation.

3. Inspect Power Quality:

   • Power Quality Analyzer: If available, use a power quality analyzer to assess the supply quality, including voltage sags or swells.
   • Harmonics: Check for excessive harmonic distortion that might impact voltage levels.

4. Examine Electrical Connections:

   • Wiring Inspection: Ensure all connections are secure and free from corrosion or damage.
   • Cable Condition: Check the condition of the power cables for any signs of wear or damage.

5. Check for External Factors:

   • Load Conditions: Ensure that the connected load is not drawing excessive current, which could lead to a voltage drop.
   • Utility Issues: Investigate if there are any known utility issues or maintenance activities that could be affecting supply voltage.

6. Run Diagnostics:

   • Diagnostic Tools: Utilize Schneider Electric diagnostic tools to assess the drive’s performance and check error logs.
   • Review Logs: Look for any related errors that may provide additional context for the undervoltage condition.