Light fixture installation, which wire to connect


I am trying to install a new light fixture in a new condo. In the fixture box, I can see wire nuts covering red, white, black, blue and green wires. It is normally to the white and black. But in this case one do I wire my light fixture to? I live in Ontario.
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Most likely white and one of the colors, except green. You need to connect a test light to the white wire and each color,one at a time, to see which other wire gives you voltage when the switch is turned on, and disconnects voltage when the switch is turned off

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RBM remove this wrote:

Then it must be the red. The red is the only one with one wire, suggesting that it is intended for this light fixture. I had connected it to the red and white on another fixture. Thought I would ask just to make sure. And what are the other colors anyway - the blues and greens?
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Generally the other wires, regardless of their color, are bringing that circuit, or another circuit, to some other outlet, switch, or light

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Thanks RBM
RBM remove this wrote:

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kim_s snipped-for-privacy@hotmail.com wrote:

Black, red, and blue are all possible "hot" wires. White is always neutral. Green is always ground. I'm not sure why you have a blue wire in there; it's very rare to see three hot wires in a box. Perhaps this is wired with the box always hot and a switch leg dropped down the wall, and the blue wire is for possible future installation of a ceiling fan controlled by a wall switch? Or someone has gotten fancy with the wiring and you've got two phases in that box? (you can save a wire if you're running a long run from the breaker box of two circuits by having two "hots" on opposite phases; the neutral can then safely be shared between them.)
In any case, what I would do would be to simply take all the wire nuts off, and test for voltage between the black and white, then red and white, then blue and white and see which one is controlled by your wall switch. The light fixture should be wired with the black wire of the light to whichever of the three is appropriate, and white to white. If you don't have a test light or multimeter, you could simply hang the light fixture from the box with a piece of scrap wire, wire up the neutral, and touch the black wire to the various potential hot wires to see what works. Grasping the wires by the insulation, of course, not the copper... (hey, some people need to have this mentioned to them.)
All of the above is ASSuming that wiring in Canuckia conforms to the same codes and standards as it does here in the YooEss.
good luck,
nate
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Thanks nate. The blues are a bunch of 3 or 4, suggesting that it is not a control wire. Does that indicate anything? Kim
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kim_s snipped-for-privacy@hotmail.com wrote:

I'm guessing this is THHN in conduit? Sounds like it is feeding another circuit in the same area from an opposite phase. Does a white wire leave the box in the same direction as the blue? Or you could just measure voltage across black and blue to see; I'm guessing you'd find 240V instead of 120V (use a multimeter or 240V bulb for this; you don't want to use a regular light bulb as a test light, it will blow almost immediately.)
nate
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kim_s snipped-for-privacy@hotmail.com wrote:

k_s:
You can not really safely assume much with house wiring. Code specifies the white is the neutral and the green is the ground, so that eliminates those (but I'd still check to make sure). You really must do as RBM said and test to see which 'hot' wires are controlled by the switch. If you can't test it safely then you shouldn't be attempting to do electrical work.
If I was there, and had my tester, I could explain everything. But I don't know:
- what kind of switch or switches control this light
- how these wires are interconnected in the box
- how many lights are controlled by this switch.
As I said, testing safely is your best bet, as well as getting your finished work properly approved by the local authoritahs.
Cordially yours G P
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Ontario like in Canada-- or California?
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