Connecting 3~ Phase 415V Pump to Single 250V - Checking Motor Windings

[ismat143]

1.What happen when we connect 3~ phase star connection 415volts pump to single phase 250 volts power supply?,it gets burn?.

and

2.How to check motor winding of any motor with multimeter?

Thank you.

 

[b.shahvir]

1.What happen when we connect 3~ phase star connection 415volts pump to single phase 250 volts power supply?,it gets burn?.

and

2.How to check motor winding of any motor with multimeter?

Thank you.

Hi,
1) you cannot connect a 3-phase motor directly on a 1-phase supply...it will not rotate as no rotating magnetic field is created by 1-phase & motor will burn-out at stand-still
You will require to connect suitable phase splitting capacitors (which produces out of phase currents of approx. 120 deg. in motor stator wdgs.) in series with the stator windings but it heavily unbalances the utility company transformers and hence is illegal...DO NOT TRY IT !

2) In my opinion, a MEGGER (insulation tester) is an accurate way of checking motor winding for faults. For further details you can google the topic of your choice. Gud luck

 

[Bob S]

All single-phase induction motors have a starting winding in which the phase is shifted using either a capacitor or high resistance starting winding in the stator. What this does is provides an apparent rotating foeld to the rotor (squrrel cage filled with laminations). Three phase do not have a starting winding because the 120 degree phase shift between the 3 input voltages already provides a rotating field. I once saw a large vacuum pump on a large 3-phase motor run backwards, because the electrician did not follow wiring conventions. Your motor will growl and burn up if you don't use all three phases..