Contactor Wiring Diagram | DOL Starter Wiring Diagram

For three-phase motors we always wire contactor, this post help you with contactor wiring and I hope after this post you will be able to wire a 3 phase motor, I also published a post about 3 phase motor wiring with magnetic contactor and thermal overload relay, but today post and contactor wiring diagram is too simple and easy to learn. 2 days ago i wired 380 to 440 volts contactor for a 3 phase motor and save these images of the contactor in PC. It is important to share with you these images but you can not learn clearly without a diagram.

How To Wire a Contactor With Overload relay

DOL starter

In the above image, I wire a contactor and a thermal overload relay for a three-phase motor, with NC and NO push button.
Note that NC means Normal Close and NO means  Normal Open, in clear words NC push button is a button which is normally close circuit and NO push button is a button which is normally open electric circuit.

NC push button we use for switching off the motor and NO push button for Switching On the electric circuit or 3 phase motor.

DOL starter box
I know these images help you very much in contactor wiring or contactor installation but you can not learn completely without a diagram. So in the below contactor wiring diagram, I have shown a contactor with a thermal overload relay, 3-phase motor and NC, NO push button switches with a complete wiring method.

contactor wiring diagram DOL starter
In the above diagram, I showed the complete method of contactor wiring and 3 phase motor wiring and wiring installation method. Note that always connect the earth wire to the electric motor body. In the above contactor wiring diagram, I did not show any type of step-down transformer or neutral wire for the magnetic contactor coil because I use a 440 volts contactor in the above circuit diagram, however, you can learn some more from the below links.

Also Read.
How to Wire a 3-Phase Motor With Contactor and Overload Relay.



I hope you learn something from this post and now you will be able to wire a contactor for 3 phase motor, however, I will soon write about more power wiring diagrams.


13 thoughts on “Contactor Wiring Diagram | DOL Starter Wiring Diagram

  • February 11, 2016 at 2:21 pm

    Thanx sir.. sir i have a query.. can we use neutral line in overload relay contact 95 96(NC), so if relay operate neutral will break And contactor will de energise.

  • February 18, 2016 at 4:40 pm

    You are right that but in the above diagram i instill the overload relay in series (95 96) and if the overload relay operate. the relay goes to normally open and the phase current will break and contactor will de energize.

  • February 21, 2016 at 8:21 pm

    Hi sir,
    Will you please give me an idea about that contactor and overload relay connection from 3 phase supply

  • May 1, 2016 at 12:05 pm

    The terminal 95-96 is always an NC contact, any terminala number, with second digit 3-4 and 5-6 are always NC. If the second digit is 3-4 or 7-8 the contacts are NO. if you connect to 97-98, the motor can never be started because no current passes the contactor coil.

  • October 19, 2016 at 3:11 pm

    Take in the normal cost of a hazard administration programming arrangement, and that arrangements are delegated top of the line or low-end. You needn't bother with a ton of statistical data points as of now yet only a general vibe of nature. this content

  • January 8, 2017 at 4:47 am

    Can I pay you to teach me how to wire the on and off switches to the contractors. To energize and switch off.

  • October 29, 2018 at 7:24 am

    Hello Sir
    i realy like your post. can you please show me how to connect earth to the ground from distribution board.

    Grateful for your nice post.


Leave a Reply

Your email address will not be published. Required fields are marked *