How to Start Three Phase Motor on Single Phase Supply

Question: How to start a three-phase motor using Single phase supply?

The single phase should be supplied to the pair of winding simultaneously with a start capacitor in series with the third winding.

The figure below illustrates the circuit configuration of the process:


A switch is added with the start capacitor and is opened upon the motor start. Sometimes a small run capacitor is retained even after starting.

The video below illustrates the above discussed schematic arrangement on a practical motor:

The video below illustrates the detailed steps of entire scheme:
Part 1:

Part 2:

Part 3:

So that was all about Motor.

Questions on Power Systems:

  1. Why liquid fuels are preferred over solid fuels
  2. Why condenser is used in steam power station
  3. Differentiate two types of boilers in thermal power plants
  4. Explain the distinguishing feature of nuclear power plant
  5. Explain the pros and cons of Nuclear power plant
  6. How hydroelectric power plants are classified on the basis of head
  7. What is forebay in hydroelectric power plants
  8. What is the role of the regenerator in gas power plants
  9. Why surge tank is built in close conduit Hydroelectric Power Plants
  10. Differentiate base load and peak load power plants

Leave a Reply