What is Start Run Common In Single Phase Motor

Mostly in our daily life, single-phase motors are used more than 3-phase motors. Stand fans, Ceiling fans, refrigerator compressors etc are all single-phase motors. Whenever we talk about the single-phase or one-phase motor we hear about the start run and common. But we don’t know what is start run and common. This post will help you that what this is in one-phase motors.

Start Run Common Diagram

A single-phase motor has two types of the coil which we called the running and starting coil or winding. and these two coils have one starting point and one ending point.

So the connection between the running winding wire and starting winding point is called common, we called him common because this point is related to both winding coils. And the other running winding wire is called the run terminal or Run connection of the motor and the other starting coil point is called the start connection. The below start, run, and the common diagram helps you for better understanding.

start run common diagram
In the above example diagram, I show two coil symbols, the running coil starting point is A and the ending point is B. The starting coil starting point is C and the ending point is D. So if we connect A and C then this will call the common because this point is connected with both coils. The ending point of the running coil is called Run and the end point of starting is called the Start.
Note A capacitor will be connected between the run and start terminals.

Message :
Now I hope you understood what is the start, run and common in a single-phase motor winding. Now if you have any questions regarding this article then you can ask me by using the below comments section.

2 thoughts on “What is Start Run Common In Single Phase Motor

  • February 13, 2017 at 9:42 am

    In Capacitor run motors do the windings have same resistance ?

  • July 13, 2017 at 5:18 pm

    I have a one Question on Refrigerator what it is when i disconnect the supply i touched the power card suddenly shocked to me ,what is the reason???


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