How To Wire Contactor And Overload Relay - Contactor Wiring Diagram

For three phase motor we always wire contactor, this post help you in 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 contactor in PC. Its is important to share with you these images but you can not learn clearly with out a diagram.

How To Wire a Contactor With Overload relay

thermal overload relay with contactor

In the above image i wire a contactor and 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.

Normal close and Normal Open push button
Contactor buttons

I know these images help you very mush in contactor wiring or contactor instillation but you can not learn completely with out a diagram. So in below contactor wiring diagram i shown a contactor with a thearmal overlaod relay, 3 phase motor and NC, NO push button switches with complete wiring method.

contactor wiring diagram
Power wiring diagram

In the above diagram i shown 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 shown any type of step down transformer or neutral wire for magnetic contactor coil because i use a 440 volts contactor in above circuit diagram, however you can learn some more from below links.

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


I hope you learn some thing 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 diagram.

Sikandar Haidar is a hub of electrical and electronics tutorials and easy diagrams.


  1. 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.

    1. 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.

    2. 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.

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

  3. This comment has been removed by the author.

  4. sir, how you create wiring diagram in pc?

    1. Dear i use different software and you can find out by googling easily.

  5. 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

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

  7. 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.

  8. This comment has been removed by the author.

  9. Can u tell me What is the solution of overvoltage

Previous Post Next Post