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Wiring Diagrams and Grounding – READ THIS FIRST!

Grounding is of the utmost importance, and every outlet and all the cables  must have the grounding or earthing system present and connected properly, both to the outlet box and to the devices as required.

Wiring diagrams on our site usually don’t include the ground connections but this does not diminish the importance of grounding.  I do this to avoid clutter on the wiring diagrams, and to focus on how to make the circuit work the way it should.   Ground wires are always the first connections that you make when connecting devices or adding circuits, and should be the last thing you disconnect when removing a device.

The CEC defines grounding as:

“A permanent and continuous conductive path to the earth with sufficient ampacity to carry any fault current liable to be imposed on it, and of a sufficiently low impedance to limit the voltage rise above ground and to facilitate the operation of the protective devices in the circuit”.

Always reference the wiring diagrams listed here to see how the grounding connections should be made, both to the outlet box, and to the devices.

Typical connection methods for an electrical outlet or receptacle.

Here is a typical connection wiring diagram for a switch device and outlet box connections.

Here is a typical connection wiring diagram for a light outlet, box and fixture connection.

Please refer to these connection wiring diagrams to get the correct details on how the ground connections should be made before checking the wiring diagram you need to reference for your particular home wiring scenario.

Another minor issue with some of our wiring diagrams is that in some cases where a white wire is used as a hot conductor, either in switch leg situations, or as a traveller in a 3-way or 4-way switch network, the white conductor is not shown with means to identify it as a hot conductor and not a neutral.  This will be corrected soon, but in practice, always identify a white wire by coloring in a section of the wires insulation with a permanent black felt marking pen, or apply a wrap of black (or red) tape near the connection points.

If you see anything on our website that you have reason to believe is not completely accurate, please let us know by going to the contact us page on the website.

– Terry Peterman, the Internet Electrician

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  • Bbkalomgir

    I would like to know which is the better electrical 110v or 220v for home use. please—–.

    • Hurley080

      depends where u are in the world

    • Kelvin

      it is 230v in India

    • Asondo Philip imba

       In my Country Cameroon ,it is 230V

  • Asondo Philip Mimba

    Can i know how many OHMS dose grounding required, when wiring a house of about fifteen rooms?

    • Kelvin

      it is better to to take a conductor having lower resistance for conductors with 0 OHM are available in market

  • nice work..

  • 123abc

    My daughter is doing a project at school about wiring a switch for a competition. I want to help her, but I don’t now how. Please help.

    • Anrgarza

      Switches are simply a disconnect. Take black wire from power source and hook it up to the bottom black screw. Take the black wire going to light and hook it up to the top black screw. Wire together the nuetral (white) wires together and connect ground wire to switch.

  • jason

    my mate just had a porch built. and the light switches wasn’t fitted i know a bit bout electrics but cant get my  head round this one he as 4 cable coming out from a single light casing 4 a double light switch. one cable from mains box. 1 cable from sealing light. 1 cable from allway 4 2 way switching and 1 cable for out side light. how can wire up this  

  • leonardo cagande

    it happens  also in my part. what’s the best action to avoid this,.no tripping in breaker when there’s a short circuit in convenience outlet.. please give me a hint 

  • Densio Garcia

    pwede mag tanong ano ba inig sabihin nang VAC-220/3.ano na linya yan 3ph o 1ph….

  • Densio Garcia

    pwede mag tanong ano bang klasing phase ang VAC-220/3.3ph o 1ph….kaso 4 na wire ang nka labas.ano bayan

  • Aladdin

    1 cable from allway 4 2 way switching and 1 cable for out side light. how can wire up this

  • Ask


  • Alfred

    If any one can let me know how to add one more electric wall outlet,do I branch it out from another outlet or do I connect it all the way to the main electrical box? thank you,,

    • MeKnowNuttin

      run it from another outlet

  • Letta Mego

    what do I do about an old house…where some of the plugins are not grounded, even though they are 3 pronged outlets. The attic was rewired a few years ago…but I don’t know what they did in the walls..I took a look at one of the ungrounded plugins…it has a hot and a neutral….and at least they are copper…AND off topic, I’m very worried about the cell phone substation two-way wireless transmitters + operating systems that the electric company is forcing on homes …calling it “smart” meters…with the purpose of forcing people to buy “smart” appliances that will be remotely controlled like a cell phone by the “smart” meter…

  • dave

    wiring a ceiling fan, the fan has a white, black and ground wire…the home has ground, white, black and red….do you need to do anything with the red wire other than just capping it and taping?

  • brian

    how do I hook up a nagf-230 to a load (pool heater) that has no neutral?


The Basics of Household Wiring DVD

"If you're looking for a good reference to help you understand simple home wiring, I personally recommend 'The Basics of Household Wiring' DVD".

Terry Peterman, the Internet Electrician
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