I am trying to install a light fixture in my Toronto condo (newly built) and to my surprise found these wires. I’m pretty sure white is neutral and green is ground. What is current? And what is the other wire for?


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  • 1
    Presuming Canada follows the US, you've got conduit (hence, not the white/black/bare you were probably expecting). White/grey are neutral, green/green-yellow are ground, everything else is hot. It appears that the label on that orange wire says "Light" (though it's hard to read, I see what appears to be "ht"). That would, most likely, be the switched hot for your light. How was it wired when you took down the old light? Just duplicate that.
    – FreeMan
    Apr 28 at 17:02
  • It wasn’t wired cause I just occupied this unit and it’s never been lived in before. You’re right that the orange wire is labelled light. If I use green for ground, white for neutral, and orange for live, what is yellow for? Yellow was tucked in way further than the rest just as an FYI Apr 28 at 17:05
  • Hello and welcome to DIY. This is a junction box to splice wires to other outlets/switches elsewhere in the room. That's what the yellows and other whites do. The orange likely comes back from a switch, as @FreeMan writes and that is your live for the switch.
    – P2000
    Apr 28 at 17:10
  • Yup, power comes "in" on one of the yellow wires and is distributed "out" through the other 3. i.e. if you disconnected all of them and turned the breaker back on, you'd find continuity on only one yellow/white pair. Odd, though... There don't seem to be enough neutral whites to go with each of the yellow/oranges. Could be a MWBC, but that seems odd for brand new construction.
    – FreeMan
    Apr 28 at 17:29
  • 1
    99.999% sure that you connect the orange to the hot lead (likely black), then pig tail from the white bundle to the neutral (likely white) and the green to the ground on your fixture, but for that 0.001% that I'm not certain about, I'd wait for an electrician to chime in...
    – FreeMan
    Apr 28 at 17:31

The novice's rule of wiring is "Not all wires in the box were put there just for your project". Lots of wires have lots of jobs to do. They don't all relate to your project. Leave them alone unless you really, really know what you are doing. Otherwise you will break the other jobs.

In particular, if wires are already bundled together, they are not "one for you and a bunch of spares". There are no spares (with rare exception). They are all doing other jobs. You can add to them, but do not separate them.

Green is ground.

White is neutral.

If you want the light to turn on and off with the switch, attach its hot wire to the single wire courteously marked "LIGHT" by the original installer.

If you want something else to happen, attach the lamp's hot wire to the yellow bundle. I suspect that will make the light run 24x7, but I don't actually know.

  • In country above USA neutral is white or grey.
    – user263983
    Apr 28 at 21:06

You should take a multimeter to that before you mess with it for sure.

In Canada, Orange/Brown/Yellow wire in a building indicates a 277V/480V system, so be wary as that's enough voltage to lock you up good. I've seen cases where an exception was obtained to use existing OBY wire for a 120V/208V system, but you may need 277V compatible fixtures.

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