How to know if ceiling is ready for light fixture installation?

[purbeast0]

We have lived in our house for almost 8 years now and in our bedroom never had a ceiling light. We do have a light switch on our wall that we are assuming is hooked up to it since all of the other rooms have that. Kind of odd that the master bedroom didn't, but it never really bothered us.

Well we are now looking to make a change and I just took off the metal cover. I've attached a picture below. There are 3 wires - red, white, and black.

Is there anyway to test this all out before getting a light and installing it, to make sure it in fact is all hooked up properly? And does that 3 wires look normal for this kind of thing? I've never done this before so just not sure. Thanks.

 

[repoman0]

Do you have a multimeter? Turn the power off and make sure the voltage between each pair is 0. Then carefully separate the wires and take the wire nuts off. Turn the power back on and CAREFULLY measure voltages. You should see 120V RMS between white and black always, near 0 between copper and white, and 120 between white and red only when the switch is on. If you have that, then it’s standard ... white on the lamp goes to white, black to red, green to copper, and black stays capped off.

Multimeter is a necessity for electrical work both for safety and troubleshooting.

Disclaimer: I am not an electrician, just a EE with an old ass house with non standard shitty 100 year old wiring

 

[herm0016]

repo is right, sounds like its wired old school for a fan and light, the fan gets constant power and you use the chain for on/off and the light uses the switch.

 

[purbeast0]

Do you have a multimeter? Turn the power off and make sure the voltage between each pair is 0. Then carefully separate the wires and take the wire nuts off. Turn the power back on and CAREFULLY measure voltages. You should see 120V RMS between white and black always, near 0 between copper and white, and 120 between white and red only when the switch is on. If you have that, then it’s standard ... white on the lamp goes to white, black to red, green to copper, and black stays capped off.

Multimeter is a necessity for electrical work both for safety and troubleshooting.

Disclaimer: I am not an electrician, just a EE with an old ass house with non standard shitty 100 year old wiring

Yes I do have a multimeter and I've used it primarily to measure voltages and stuff in my arcade games while it's powered on, so I am somewhat familiar with using them on live wires.

I will give that a go when I have time.

Is the black wire that you say stays capped off, for a fan if you were to hook one up? Just curious.

Thanks!

EDIT:

Also, wouldn't I have to take the wire nuts off before measuring the voltage between each pair? So I can expose the wire?

 

[repoman0]

Yes I do have a multimeter and I've used it primarily to measure voltages and stuff in my arcade games while it's powered on, so I am somewhat familiar with using them on live wires.

I will give that a go when I have time.

Is the black wire that you say stays capped off, for a fan if you were to hook one up? Just curious.

Thanks!

EDIT:

Also, wouldn't I have to take the wire nuts off before measuring the voltage between each pair? So I can expose the wire?

As herm said you can use the black for fan constant power that then gets controlled by a chain. You’ll have a choice usually depending on the fan. I’ve hooked them up in my house just controlled by the switch all around and then use two chains because my wiring is old and doesn’t have the extra switched wire

I usually try to jam some leads in there before taking the caps off just so I can do a safety check that the breaker actually controls what I’m working on .. it works sometimes. A real electrician would have an inductance wand thing that checks just by waving near the wire. You can also measure at the switch if it’s easier .. with the switch off you should measure 120V across it with the breaker on and 0 with it off. You can also throw safety out the window and just take the caps off really carefully if you’re pretty sure you have the right breaker ...

 

[OILFIELDTRASH]

If not sure turn off power at the breaker to the whole house and use a flashlight or open a window for light.

 

[NutBucket]

repo is right, sounds like its wired old school for a fan and light, the fan gets constant power and you use the chain for on/off and the light uses the switch.

Could also be there are provisions for two switches so the fan can be controlled from the same wall switch location with something like this:

OP should carefully remove the switch plate and verify the 3 wires are in there. My money is on yes.

 

[purbeast0]

Well for what it's worth we are not installing a fan so in the end, it doesn't really matter if the 3rd wire is hooked up for a switch.

I am like 99% sure there is a wire there though, as our son's bedroom has a fan that can be controlled by a switch on the wall next to the light switch. It has a chain on it too but we keep that one on all the time and control it from the switch.

 

[Greenman]

repo is right, sounds like its wired old school for a fan and light, the fan gets constant power and you use the chain for on/off and the light uses the switch.

Or both legs are switched. Need to look in the switch box.

 

[Red Squirrel]

Yeah going to guess this was setup to allow a fan, I would check the switch box to see how they set it up in there. If you do choose to put a fan it will give you flexibility of being able to turn the light or fan part separately.

 

[feralkid]

If not sure turn off power at the breaker to the whole house and use a flashlight or open a window for light.

Usually light comes through a window without having to open it, but YMMV.

 

[Meghan54]

Usually light comes through a window without having to open it, but YMMV.

Kinda depends upon how dirty said windows are...or have said windows been redneck repaired by putting plywood over the whole window?

 

[purbeast0]

Okay I'm a little confused by this installation. Here is a picture of how they want you to install the wires. It's got 3 screw terminals. One is ground (which I assume I would attach my bare copper wire to) but the other two just say "power".

I have a white, red, and black wire, and I am not sure which to attach to which terminal.

Anyone have any idea? Would that just be the white and red wires?

 

[Red Squirrel]

Woah that looks like it's from like the 1920s or something. Going to guess one of the power input wires is just neutral. Maybe the terms hot/neural did not exist back then. I would get a continuity meter and check between the power connector on the light and the inner screw part of a socket, the one that has continuity will be neutral. (do this with it not connected to anything of course) The idea being that neutral is tied to ground at the panel so if your finger accidentally touches that part of the socket you don't get a shock.

Is this even rated for 120v though? It says battery box. Wonder if it's designed to run on a low voltage system.

 

[purbeast0]

Woah that looks like it's from like the 1920s or something. Going to guess one of the power input wires is just neutral. Maybe the terms hot/neural did not exist back then. I would get a continuity meter and check between the power connector on the light and the inner screw part of a socket, the one that has continuity will be neutral. (do this with it not connected to anything of course) The idea being that neutral is tied to ground at the panel so if your finger accidentally touches that part of the socket you don't get a shock.

Is this even rated for 120v though? It says battery box. Wonder if it's designed to run on a low voltage system.

This is the light:

https://www.amazon.com/gp/product/B07THNDNB7

I was surprised how shitty those instructions were too. I just wanted to connect some wires with wire nuts lol.

 

[Red Squirrel]

Oh Amazon that explains it. Straight from China probably. I tend to avoid online for electrical stuff unless it's like Home Depot, Canadian Tire etc... That light is probably not UL approved or anything like that. But yeah I think it does not matter what terminals you use for black or white. Probably won't be to code though, but it seems to have good reviews and no one reported a fire, so that's good.

I don't quite understand their mounting though with "the walls" lol. Normally you will have a setup kind of like this:

And the light just screws into the middle with a knob or something in the middle of the fixture to hold it up, after you did the wiring with the wire nuts.

 

[purbeast0]

Oh Amazon that explains it. Straight from China probably. I tend to avoid online for electrical stuff unless it's like Home Depot, Canadian Tire etc... That light is probably not UL approved or anything like that. But yeah I think it does not matter what terminals you use for black or white. Probably won't be to code though, but it seems to have good reviews and no one reported a fire, so that's good.

I don't quite understand their mounting though with "the walls" lol. Normally you will have a setup kind of like this:

And the light just screws into the middle with a knob or something in the middle of the fixture to hold it up, after you did the wiring with the wire nuts.

That's just the engrish translation. It means ceiling. There is a bracket you screw into the ceiling and the light screws to the fixture.

 

[NutBucket]

Power is typically white/black (white = neutral, black = load). You need to check behind the wall switch to see what is connected.

I read that diagram to mean polarity of the incoming power doesn't matter. And you don't have a ground; the junction box should be grounded though.

 

[bbhaag]

Cut and cap the red wire then tuck it up in the box out of the way. You don't need it it's just there to supply constant power to a ceiling fan. That way the fan still spins even though the lights are off.

Connect the white wire and the black wire in your box to the power input wire terminals outlined in the diagram you posted. Connect your bare copper wire to the ground wire terminal outlined in the diagram you posted above.

 

[purbeast0]

Cut and cap the red wire then tuck it up in the box out of the way. You don't need it it's just there to supply constant power to a ceiling fan. That way the fan still spins even though the lights are off.

Connect the white wire and the black wire in your box to the power input wire terminals outlined in the diagram you posted. Connect your bare copper wire to the ground wire terminal outlined in the diagram you posted above.

Thanks.

Turns out the fucking light was missing a few things, including a mirror on the light, so I ordered a new one. I didn't even remember but I had ordered one from Amazon Warehouse before since it would come much quicker and was $20 cheaper. I've always gotten stuff basically brand new from the warehouse deals before but this time nope.

So now waiting until Monday for the brand new one to come on Monday. I do have the bracket already installed though so it should be simple to just wire it up.

 

[JEDI]

This is the light:

https://www.amazon.com/gp/product/B07THNDNB7

I was surprised how shitty those instructions were too. I just wanted to connect some wires with wire nuts lol.

can your outlet box hold the weight of that big light?
or are you going to use toggle bolts into your drywall ceiling to hold it up?

 

[purbeast0]

can your outlet box hold the weight of that big light?
or are you going to use toggle bolts into your drywall ceiling to hold it up?

It's already been installed.

It comes with a bracket that you install with dry wall anchors that the light screws to.

The pictures are EXTREMELY deceiving with the size. The thing is tiny. Even my wife that picked it out said it was way smaller than she expected, but she's fine with it.

The light is kind of stupid though because it has 3 light settings on it, and it literally just switches to the next one when you turn it off then back on. So if you want the same light setting all the time, you have to flick it on/off 3x to get to it. But my wife doesn't care and I'm only in my bedroom to sleep so I don't even use the light.