Mike Dolt Enterprises
Mike Dolt Enterprises
User: joebell, Location: New Hampshire
Asked on: Monday, March 28, 2011 at 6:17 pm EDT
Answered on: Tuesday, May 14, 2024 at 3:23 am EDT
Question: We are attempting to connect a 6 lead 460 volt 100 HP part winding motor to a VFD. We connected leads 1 & 7 to T1, 2 & 8 to T2 and 3 & 9 to T3. We are getting fault codes on the drive and was told that the breaker in the panel tripped when the drive was put in bypass. I'm wondering if this motor and drive are compatible or if we have the motor wired correctly?
Compatibility Check
Confirm that the VFD is rated for the motor's voltage (460V) and horsepower (100 HP). Check the VFD's documentation to ensure it supports part winding motors.
Wiring Verification
T1
Leads 1 & 7 (U0 & V0)
T2
Leads 2 & 8 (V0 & W0)
T3
Leads 3 & 9 (W0 & U0)This is the correct wiring configuration for part winding motors.
Possible Causes of Faults
Incorrect wiring
Ensure the leads are connected correctly as described above.
Loose connections
Check all connections for tightness.
Overload
If the motor is overloaded, the VFD will fault due to excessive current draw.
Ground fault
Ensure the motor and VFD are properly grounded.
Drive settings
Verify that the VFD parameters, such as voltage and frequency limits, are set correctly for the motor.
Breaker Tripping in Bypass
When the VFD is in bypass mode, power flows directly to the motor. If the motor has an internal fault or is wired incorrectly, the breaker may trip when the bypass is enabled. To troubleshoot, disconnect the motor from the VFD and use an ohmmeter to test for continuity and ground faults.
Troubleshooting Steps: Recheck the wiring connections carefully. Inspect the motor for any visible damage or loose connections. Test the motor's continuity and insulation resistance using an ohmmeter. Contact the VFD manufacturer for assistance with drive settings and fault codes. If all else fails, consult an experienced electrician or motor expert. Flag for review