Help wiring ceiling lights

[D'z Nutz]

I picked up some lighting for my ceiling and I need some clarification on the wiring.

Here's what's coming from the ceiling
http://www.typicalfish.com/images/beyond/lighting_001.JPG

From what I've read online, here's what the general consensus is:
- White = neutral
- Green = ground (plus it's screwed into the metal mounting bracket)
- Blue = ???

What the heck is the blue?


Here's the wiring for the lighting fixture.
http://www.typicalfish.com/images/beyond/lighting_002.JPG

Not pictured is the ground wire from the fixture, which is obviously the bare copper wire, however the other wires are both black. Does the one with the writing connect to the white and the one without writing connect to the blue? Unfortunately the instructions on the lighting are pretty useless as they are just pictures with no descriptions.

[danno]

you must live in a condo to get a blue wire, you probably have pipe in that slab box in the ceiling. blue represents the thrid phase of a 3 phase panel. as for the hook up blue is your hot it will go to the all black wire, the white will go to the one with writing but it may also have ribs on it, and ground to to green.

[AndyL]

As above - blue to black, but in my house - blue is switched power in ceiling and outlets (have a couple switched plugs + always on (former ceiling fan?) Power sources in the ceiling boxes)

[C_Dave45]

Green is the ground. The other two just connect to your fixture wire...doesn't matter which one goes to which colour.

[OU812]

yep blue is your hot so wire to black

[D'z Nutz]

Thanks guys! I got it wired in!

[Zero102]

Originally posted by C_Dave45
Green is the ground. The other two just connect to your fixture wire...doesn't matter which one goes to which colour.

Incorrect and dangerous :whipped:
As said above:
White is neutral, and on his fixture wiring the identified conductor (by writing or ribs or both) is also the neutral.
Blue is hot for him and the all black non-ribbed fixture wire is for the ungrounded (hot) wire.

As the light comes with a ground wire it is NOT double insulated and you cannot safely swap the hot and neutral for it.

[C_Dave45]

^ IF he swapped the two wires, nothing would happen.

[90accord]

Nothing would happen the light would work but the actual socket on the light would be energized makin it a hazard when changing bulbs or if one breaks. To make it proper code wise and safety wise it should be wired with the black to hot

[PD77]

Originally posted by C_Dave45
^ IF he swapped the two wires, nothing would happen.

Do you like it when people cut corners doing your line of work?

Probably not.

The colors are there for a reason, by reversing them you are now making the threaded portion of the light socket energized instead of the button at the base of the socket. The light will still work but there is a much greater chance of someone getting shocked.

[98brg2d]

Plenty of light fixtures use clear sheathed stranded wire with no markings, what are you to do in that situation? (The instructions do not mention anything most of the time, some of the time they say to match up colors but there are none!?) There is no way to differentiate between the two.

[sillysod]

^^^ easy way to tell, PD77 is correct the center of the socket is always hot.


use your meter to do a continuity test to see which conductor goes where.

http://home.tulsaconnect.com/toug/cpf/fluke%2087.JPG

[90accord]

Usually the wire is marked with writIng if it's hot, always check wit a meter

[Zero102]

Originally posted by 98brg2d
Plenty of light fixtures use clear sheathed stranded wire with no markings, what are you to do in that situation? (The instructions do not mention anything most of the time, some of the time they say to match up colors but there are none!?) There is no way to differentiate between the two.

To be UL/CSA certified they MUST have an identified conductor, whether it is by writing or by ridges on the insulation itself. To be sold in this country the lights must be certified.

[danno]

I've never hung a light that wasn't marked or had ribs on it. It might not say neutral on it but if it has writing on it and the other doesnt it will be your neutral.

[rx7_turbo2]

Originally posted by danno
I've never hung a light that wasn't marked or had ribs on it. It might not say neutral on it but if it has writing on it and the other doesnt it will be your neutral.

Agreed, I'm a Journeyman as well, and have only seen one fixture that had no markings, it was a Chinese made unit bought from some flee market, had no Ul/CSA identification. I refused to install it.

They are identified for a reason, and a very important one, not following those identifications could result in personal injury or property damage.

[98brg2d]

Looks like I may need to double check the latest install, thanks for the info on the continuity test.

Edit: more questions: can I check for correct wiring by testing between the base and the threads in the socket? I have not tested AC recently (not since school) and I haven't been able to determine through searching if polarity can be determined without testing to ground. I would think that the numbers would look identical either way since all I will see is rms (no sign). Can I test to ground at a nearby receptacle? i.e. continuity between the threads or base and the neutral and/or voltage between threads or base and ground.