What can cause an SCF2 (Impedant short circuit) fault on the ATV61 and ATV71 drives?
Issue:
Causes for SCF2 fault on the ATV61/ATV71 drives.
Resolution:
- Check the motor and motor cables
- Disconnect the motor from the drive.
- Test the motor cables and motor insulation using a 1 kV megohmmeter (Megger).
- Check motor grounding
- Verify that the motor is properly grounded.
- Confirm that a ground conductor is connected directly between the drive and the motor.
- Check the switching frequency
- Verify the drive's switching frequency and adjust it if needed.
- Run the transistor diagnostic test
- Go to [1.10 DIAGNOSTICS].
- Run the Transistor Test using the drive's auto-diagnostics function.
- Consider the motor cable length
- For long cable runs between the drive and motor, consider using a load reactor, dV/dt motor filter, or sine-wave filter.
- Test the VFD output
- Disconnect the motor leads.
- Disable Output Phase Loss detection.
- Set the motor control type to V/F 2pts.
- Run the drive at several frequencies, such as 20 Hz, 40 Hz, and 60 Hz.
- At each frequency, measure the phase-to-phase output voltage across all three phases.
- Compare the readings. The output voltages should be balanced within several volts.
Safety note: Perform insulation and voltage measurements only with appropriate electrical safety procedures and qualified personnel. Ensure the motor is disconnected from the drive before performing the 1 kV insulation test.
If this article does not answer your question, check out our FAQ database that has answers to more commonly asked questions:
Frequently Asked Questions - Schneider Electric (se.com)
If this FAQ did not solve your issue, you can call us at 1-888-778-2733 Option 2 and then 4 or e-mail us atdrive.products.support@se.comto create a case with our Technical Support Team.
If you are not located in North America, please contact your local Customer Care Center for assistance:
Released for: Schneider Electric Australia
