Old Florescent Light Wiring

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Old 08-07-20, 06:40 PM
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Old Florescent Light Wiring

I bought this house in 1980 (the house was about 20 years old at the time) and a florescent light in the kitchen has always worked until recently. Replacing light bulbs did not work and replacing the starters did not work. I thought I might be able to replace the ballast until I saw what I was up against. No YouTube video covered anything like this, so I put it on hold. I just got a new LED light to replace the old florescent light. I thought it would be simple. Black to black and white to white. Got it all apart to find something I have no idea how to proceed. Getting an electrician could take a couple of months, so look at the photos below to see what this is all about.

First photo below shows the old light. Second photo shows the wires after I removed the light. The light switch was off, so I figured I was good, but sparks flew when I pulled the old fixture off the wires.

Second photo below shows the wires. The green arrows point to two wires that are dead, switch on or off. The two red arrows point to two wires that are hot no matter if the switch is on or off. The blue arrow points to a wire that doesnít seem to do anything. There is only one switch that controls this light. Why are there so many wires and why is one set dead all the time and one set hot all the time?

The new light fixture had one white wire, one black wire and a ground and that is what I expected to see when I took the old one off.






 

Last edited by PJmax; 08-07-20 at 07:57 PM. Reason: added labeling
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Old 08-07-20, 08:04 PM
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This setup is called a switchloop. The power comes into the fixture. Hot is sent down to the switch on the white and returns switched on the black.

You connect the black with red arrow to the white of the green arrow. That white wire should be taped a color different from white to let it be known it's not neutral.

Your fixture white connects to the white with the red arrow and the black with the green arrow.
The grounds get connected together and then to the ground wire or metal fixture case.
You need to use a proper connector or bushing to bring the cables into the fixture.


I'm somewhat concerned about that extra white wire.
Was it connected to anything ?
It looks like it was capped with an orange wire nut. That should remain.
 
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Old 08-07-20, 09:08 PM
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Since I started this thread, I have found that the switch for the light that has two outlets next to it that the outlets no longer work and there is another outlet out of the photo that the toaster and coffee grinder are plugged into that now no longer works. I thought I was confused when I started this thread, but now Iím baffled. Below is a photo before I took the old light down and below that is the switch that controlled the light and controlled nothing else.





There is one white and one black going to the switch and one black wire from the switch to the two plugins.

The light was installed by the former owners and is wired separately from anything else in the kitchen and is not on the circuit breaker box that is in a cupboard in the kitchen. This is a super old trailer that was inclosed with a stick frame and the trailer part of the wiring is separate from anything else. The florescent light was added to give more light to the kitchen and we miss it.
 
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Old 08-07-20, 09:11 PM
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Is the white wire just run loosely ?
There should be a three wire cable between the light switch and the light.
Code doesn't allow a single wire to be run outside of a common jacket.
 
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Old 08-07-20, 10:58 PM
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would suspect a switch loop and the extra white was a neutral for the plug in may not be up to code but it is an old house.
 
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Old 08-08-20, 06:27 AM
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Is there a single white in the switch box?
If yes where does it go?
 
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Old 08-09-20, 02:43 PM
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I'm somewhat concerned about that extra white wire.
Was it connected to anything ?
It looks like it was capped with an orange wire nut. That should remain.
Unfortunately I did not pull all the wires down and take a photo before I disconnected them, so I have no idea what that lone white wire was connected to but I believe it was connected with black electrical tape. You can see that tape in the photo.
 
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Old 08-09-20, 02:54 PM
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Pjmax - Thanks for putting the labels on my photo. That helps to paint a clearer picture for me, but I do wish I had pulled the wires down and taken a photo before disconnecting them, but until I had everything disconnected and the old fixture gone and discovered the two hot wires, even tho the switch was off I still really thought this was going to be simple. Iíve done some simple wiring over the 40 years Iíve owned this house, but nothing like this. I just donít know what that lone white wire is for.

This is in the old trailer part of the house, but the wiring for this fixture was done by the people I bought the house from and is totally separate from the old trailer wiring. Still, this fixture was done just before I bought the house, so it is about 40 years old. Nothing about this house and code surprises me.
 
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Old 08-09-20, 02:59 PM
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Is there a single white in the switch box?
If yes where does it go?
There was no switch box. That single white wire labeled with blue arrow in my photo remains a mystery.
 
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Old 08-09-20, 03:23 PM
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So there is no box behind the switch and two receptacles ?

There is one white and one black going to the switch and one black wire from the switch to the two plugins.
Ok.... so we know that two wire to the switch is a switch loop wired incorrectly since they are using the black wire as hot and to also run the receptacles. That means that single white wire must be the neutral wire to the receptacles. They cannot run on a hot wire alone.

Since I can only see 2) two wire cables and the single white wire..... that single white wire would need to be connected to white with the red arrow.

This is what it appears you have there...... (tape switched hot wire to light... black)

 
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Old 08-09-20, 07:01 PM
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One point I'll make about your old fluorescent fixture is that it unlike many that have a single ballast for two lamps, yours uses two independent ballasts. I note that because if both bulbs went out at the same time, it's very unlikely the ballast or fixture components are to blame unless a power surge or something like blew them out (in which case you'd probably have other issues). The way the fixture wires to the supply isn't all that special except it has two hots and two neutrals since it's essentially two lights in one.
 
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Old 08-09-20, 10:45 PM
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So there is no box behind the switch and two receptacles ?
Yes, there is a box behind the switch and two receptacles. I thought you were talking about where the old florescent light was.
 
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Old 08-09-20, 10:51 PM
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One point I'll make about your old fluorescent fixture is that it unlike many that have a single ballast for two lamps, yours uses two independent ballasts. I note that because if both bulbs went out at the same time, it's very unlikely the ballast or fixture components are to blame unless a power surge or something like blew them out (in which case you'd probably have other issues). The way the fixture wires to the supply isn't all that special except it has two hots and two neutrals since it's essentially two lights in one.
Yes, both lights went out at the same time. Iím not aware of any power surge. Replacing both lights and both starters did nothing.
 
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Old 08-10-20, 12:28 AM
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If nothing works you have no power to the fixture
Fluorescent lights rule LED is 100% garbage imported junk (as you can tell from this and other posts of mine I 100% hate and dispise what LEDs are doing to the lighting industry
 
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Old 08-10-20, 06:53 PM
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What's nice about some of these old fluorescent fixtures is how serviceable they were. For example, even if the ballasts were bad, they can be replaced. A quick web search finds this one that should fit and I'm sure there are plenty of others. Those lamp holders as well as the starter sockets are also removable in the event they are ever damaged. Although it sounds like you already have a new LED fixture, LED tubes are also a good option and they can be changed as easily as any other bulb if they ever go bad. Many of the LED fixtures being sold today are one-piece units. They are supposed to be reliable, and generally are if they come from a reputable manufacturer, but should something go wrong with one you generally need to replace the whole unit. On commercial units sometimes the drivers and even LEDs are replaceable, if you're able to find compatible parts, though they're not as universal as fluorescent components.

I'd be interested in knowing if the new fixture works. I'd suspect a bad wall switch or wire connection before the ballast. The likelihood of both of those chokes shorting or going open circuit at the same time seems very low. They can fail, but those simple choke ballasts tend to be very reliable. They also don't suffer from the starting issues that many of the old rapid-start ballast have when the fixture isn't grounded or reduced-mercury lamps are used.
 
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Old 08-11-20, 11:26 AM
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I have decided not to mess with this any further. I actually got hold of an electrician and tho it will be one to two weeks before he can actually do the work, Iíve been without the light for about 4 months anyway and have an extension cord going to the coffee grinder and toaster, so Iíll live.

For what itís worth, here is the new fixture. I was surprised that it has two LED strips in it. I chose this light cause it looks just like the old light and I figured installation would be easy. I could not have been more wrong. Also, the damn thing is made in China. Oh well. Lighting fixtures and all the different types of lighting bulbs, strips or what ever is so dang confusing itís a crap shoot as to what I actually end up with.


 
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Old 08-11-20, 07:16 PM
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The new unit doesn't look too bad, could be serviced if it ever malfunctioned, though a bit more skill would be required given the strips are soldered in. Personally I'd repair the old fixture if the lens was in good shape, rewiring it for LED tubes if need be, but it's a matter of preference. I'm not too fond of integrated LED fixtures myself, but they are increasingly popular and many have had good experience with them.

If you have the fluorescent down, you could test without special equipment provided you have a spare lamp cord. Connect hot to the fixtures two black wires (that should lead to the ballasts) and neutral to the fixtures two white wires (should go to lampholders on the opposite side). By the way, lamp cords have ridges on the neutral side. Then plug it into a known good outlet, and see if what happens. If it works, it's something else in the circuit. If not, it's probably the light itself. Those choke ballasts are reliable. However, if they do short they'll burn out the tube's cathodes immediately, so it's ideal to test with separate bulbs and starters. As I said before, if they did in fact fail at the exact same time, it's very unlikely to be ballast-related. Make sure the starters are the correct type (probably FS-2), wire connections are secure, and lamps and starters are properly seated.

Also, here is a circuit diagram for the old fixture (or half of it). I remember pulling down a two lamp cabinet fixture with a similar configuration and it looked like mess of wires at first, but it's actually relatively simple once you see how it's laid out.
 
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Old 08-28-20, 06:20 PM
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I decided to hire an electrician to do this, but in 3 weeks of trying, nobody seems interested so I am forced to do this myself. What I did today was to hook the two black wires together and the two white wires together. That got my outlets working again. I am thinking that to hook the new light up, the white wire from the light needs to get connected to the two white wires in the photo below, and that one lone white wire would get connected to the black wire on the new fixture. Would I be correct in trying that?


 
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Old 09-01-20, 06:52 PM
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That looks correct to me, though feel free to check with @PJmax to confirm considering he was the one who labeled everything in an earlier post. I'm only a DIYer, so if you're at all unsure, wait for a pro.

It sounded like you had one white wire that should truly be a hot which is part of your switch loop. Do you have a multimeter or other voltage? If it was me I'd test for 120V between the white and ground before installing the fixture.

I'm still curious about what happened to the original fixture. Maybe you checked out the switch already, to rule it out as a possible culprit.

Another point before you proceed, does that new fixture have a metal channel cover that fits over the driver and wiring? If not, do the instructions state whether or not a junction box is required? Most fixtures with a channel cover are rated for use as a raceway, which means no box is required. Splices can be made within the fixture itself. However, sometimes manufactures opt to save a few cents on steel by not including one. This often results in the fixture requiring that connections be made in a box for fire and electrical safety reasons. Of course you could just ignore that, but I wouldn't advise it.
 
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Old 09-02-20, 05:46 PM
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I hooked it up just minutes ago as I described in my last post and the light comes on and stays on. The switch does nothing. I give up. At least I got my outlets working.

I found a cord that I could test the old light with, but never did it. The new light is bright and I was working in the kitchen with the sun coming in every window and the new light was bright. Too bad I canít figure this out and get that light working with the switch.

We have one electrician in town. Everyone Iíve talked to says he doesnít answer the phone, but I got hold of him the last time I needed an electrician a couple of years ago. He said he would call me back. Never heard from him again. Only electrician I have been able to get hold of is 60 miles north of here. They said one to two weeks max. Itís been over 3 weeks and Iíve heard nothing. It hasnít always been like this. Used to be a time I could get an electrician the day I called or the next day.

EDIT: After I posted this I read my last post and I did not hook the new light up like I said in my last post, so once again I switched the wires so that it was exactly like my last post. Outlets still worked, but not the light. Wonít come on at all. I was too frustrated to even think about taking a photo. I really wish I had just pulled the wires from the original light down so I could see what went to what and taken a photo of that. 20/20 hindsight is a booger, but I would have never imagined that I would find what I found. Shouldnít this have been as simple as running a wire from the switch to the light???
 

Last edited by wingspar; 09-02-20 at 06:07 PM.
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Old 09-04-20, 09:38 AM
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So it sounds like the lone white wire is supposed to be the hot returning from the switch? That's not how the earlier diagram has it labeled, but if I look at your original photo where the old fixture was still up, it does appear that the white which connects to the fixture's black wires is not in a jacket, so I think you have it right. It's the white wire that enters the orange wire nut in that old photo. Have you inspected the switch and the wiring at the outlet? I think you did before, and did you verify that it was the same single white wire which went to the switch?

As mentioned previously, your original fixture had two ballasts. If both tubes truly did quit at exactly the same time, the odds of it being the ballasts or any of the fixture components are slim. Therefore, even if you've wired the new fixture properly, it's not going to work unless the original issue truly lied with the old fixture or the supply connections at the fixture. It might have been the switch or wiring to or from the switch all along. I think you're struggling because there are too many variables. You don't have confirmation that your wiring matches the original configuration, nor do you have confirmation that original fixture is in fact faulty. I'm not an electrician, but the way I'd solve a problem like this is to break it down into smaller pieces. For instance, removing and bypassing the wall switch would inform you as to whether the switch is defective. Testing the old fixture won't help you directly, but if it works then you almost certainly have a fault elsewhere that caused the issue to begin with.
 
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Old 09-04-20, 01:37 PM
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After I last posted and calmed down a little, I started to wonder if it wasnít the switch this whole time, so I actually found a new switch in my shop this morning and installed it. BINGO!! Everything works now! And to top it all off, replacing the switch was the most simple thing I did in this whole project. Took less than 10 minutes to replace, and that counts a couple of trips out to my shop. So, there was nothing wrong with the original florescent light in the first place.

I do appreciate the help in this thread as I never could have figured out the wiring if it wasnít for the help in this thread. Thank you.
 
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Old 09-04-20, 03:56 PM
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Awesome you got everything working! I had a hunch it was the switch. Those choke ballasts are one of the simpler and dependable methods of driving a fluorescent lamp, hard to imagine two of them going bad. I don't know which fixture you decided to go with. That LED should be reliable, but it wouldn't surprise me if the old fluorescent could outlast it, at least in terms of the control gear.
 
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Old 09-05-20, 02:32 PM
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The new light is so much brighter than the old light. I used it last night and it was almost too bright. Makes it look like the entire kitchen ceiling is one big skylight in the middle of the day. I have been thinking of under the cabinet lighting for a long time as this kitchen is so dark, but this new light puts light where Iíve never had it before and Iím starting to wonder if I still want to add some under the cabinet lights.
 
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