Single Phase Motor Winding Resistance -Start Run Common

This post is about the single phase motor winding resistance. In this post, you will learn about the single-phase induction motor winding resistance. In the single-phase induction motor, we have two types of winding. One is called main winding also known as running winding. And 2nd winding is called auxiliary winding also known as starting winding.single phase motor winding resistance

Single-Phase Motor Winding Resistance

This is very important to know about the single-phase induction motor winding resistance. Because we did not know about this, we can connect the supply and capacitor to the motor. Or we cannot do the capacitor connection with a single-phase motor. As I have written above single-phase motors have two types of winding and each winding has its resistance. But which winding resistance is high than other winding, that’s is an important point…

In the single-phase motor, the main winding is made from thick wire which means that this winding will me low resistance than starting winding. The starting winding is made from thin wire (SWG) which means that this wire will be high resistance to the other one.
For example, if the main or running winding is made from the 21 SWG and its resistance is 2O ohms. And the starting winding is made from the 24 SWG wire. The resistance of this winding will be high.
We know that the point at which the two windings connect together is called the common point. And the main winding resistance is low than the auxiliary winding. which means that the low resistance between common will be the run and high resistance with common will be started. So the supply will be going to the common and run and the capacitor will be connected between the run and start.
This is an explanation of single-phase motor winding resistance, However, if you want to learn more about how to identify the start run and common in a single-phase motor then read the following articles for a complete understanding…

I hope now you will get some knowledge about single phase motor winding resistance and now you will be able to find out about the main and auxiliary winding in a single-phase induction motor. However, if you have any questions about this post then you ask your question in the below comment section.

4 thoughts on “Single Phase Motor Winding Resistance -Start Run Common

  • April 14, 2018 at 1:57 am

    Assalam o Alaikum Sikandar Bahi.
    kia hal hain.
    Mein Electrical Technician ki job ka lia tiyari kar raha hon aap ki website say bahut faidah mil raha hai.
    Jazaka Allah
    Munawar Abbas
    Dera Ghazi Khan

  • September 18, 2018 at 12:37 am

    Run + Start = Total Resistance
    Run = Total Resistance – Start
    Start = Total Resistance – Run

    On a simple motor with three leads there are a total of three combinations to measure. You measure the resistance of each of the three combinations. The highest measurements is the total resistance of both windings together in series. The next highest is the start winding. The lowest measurement of resistance is the run winding.

    The motor in the picture with the extra two wire for the start capacitor is a little more tricky, but if you disconnect the capacitor and measure the resistance of those two wires, it should be both the start and run together and is the total resistance of them both.

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