Mike Dolt Enterprises
Mike Dolt Enterprises
User: Rsteenson, Location: Wisconsin
Asked on: Monday, May 2, 2011 at 10:41 pm EDT
Answered on: Tuesday, May 14, 2024 at 4:53 am EDT
Question: I installed an ATS22C11S6U soft-starter on a 40 hp 230v motor. The motor is being fed from a "Ronk" phase converter. I have had nothing but numerous faults on the soft starter from short circuit to phase loss to over current. My voltages are showing the same as a hi-leg delta system.....although "c" to "b" phase is showing almost 280 volts, which makes me curious. The motor has been run on the phase converter for a couple years but my customer has had problems with the original across-the-line starter. (what a surprise on a 40 hp motor, right?) why the original sparky didnt install one is beyond me. any help would be greatly apprecciated!
Possible Causes of Soft-Starter Faults
1. Incorrect Wiring
Ensure that the soft-starter is properly wired according to the manufacturer's instructions. Verify that the incoming voltage matches the voltage rating of the soft-starter.
2. Voltage Imbalance
The high voltage between phase "c" and "b" (280V) suggests a voltage imbalance. Phase converters can sometimes cause voltage imbalances, especially with larger motors. Measure the voltages between all three phases to confirm if there is an imbalance.
3. Motor Overload
The overcurrent fault may indicate that the motor is overloading. Check the motor for any mechanical issues or improper loading.
4. Phase Loss
A phase loss fault can occur if there is a problem with the phase converter or the incoming power supply. Use a voltmeter to measure the voltage between each phase and ground to ensure that all phases are present.
5. Incorrect Soft-Starter Settings
Verify that the soft-starter settings are appropriate for the motor. This includes setting the ramp-up and ramp-down times and the current limit.
6. Motor Faults
A faulty motor can also cause soft-starter faults.* Test the motor with a megger to check for insulation resistance and ground faults.
Troubleshooting Steps
1. Inspect Wiring
Check all wiring connections for loose or incorrect wires.
2. Measure Voltage
Use a voltmeter to measure the incoming voltage and the voltage between all three phases.
3. Check Motor Load
Ensure that the motor is not overloaded or has any mechanical issues.
4. Test for Phase Loss
Use a voltmeter to check for phase loss by measuring the voltage between each phase and ground.
5. Adjust Soft-Starter Settings
If necessary, adjust the soft-starter settings for optimal motor operation.
6. Test Motor
Use a megger to test the motor insulation resistance and ground faults.
7. Contact Ronk:
If the issue persists, contact the manufacturer of the phase converter (Ronk) for technical support. Flag for review