Three-phase imbalance of the motor
Thread Content
For a 160KW pump, the current during normal operation is generally around 200A; currently, the current on phase C has reached 225A, with soft start control in use. There are no problems with the electrical wiring; what do you think might be the likely source of the issue? Thank you all. . .
If the electrical wiring is fine, is the three-phase voltage balanced? Also, check whether the three-phase windings of the motor are balanced; I hope this helps you.
Is there a ground fault? Generally, abnormal current indicates a problem at the grounding point
The specific inspection steps are as follows: 1: Test whether the no-load current of the motor is balanced. 2. Check whether the motor wires in the motor junction box are loose. 3. Check whether the soft starter and its bypass wiring are loose; based on the symptoms you described, it’s more likely that the wiring is loose!
The current imbalance should not exceed 10%. Check what the currents of the other two phases are; if there are no other abnormalities, it can continue to operate, but keep an eye on it
1. First, check the power supply voltage. 2. Test the insulation. 3. Measure the DC resistance of the motor windings. Note: When the windings are unbalanced, the motor vibrates severely.
First, check whether the three-phase voltages are normal, and also verify whether the resistance of the motor’s three-phase windings is balanced.