Re wiring a T 8 fixture

[mx842]

I got some new light fixtures that were too good to turn down but you know how that goes. Anyway they were supposed to be for 120V but after I had them all mounted and started to wire them in I found out they were 277V. I had spent a day and a half taking down old fixtures that I wanted to replace and adding new ones in places I needed more light.

I didn't want to scrap the whole bunch so I decided to just buy new ballast which I did. They had 3, 4' t 8 bulbs in them but there was enough room in them to add another bulb which I decided to do which wasn't a big deal to at least 4 of the fixtures. When

When I bought the ballast I got the ones that could be used in both 3 and 4 fixture's. I even bought a couple extras for spares because they were the same ballast that were in some of the other fixtures I already had in the shop. The problem is that I have wired these things 20 different ways to sunday and they still wont work.

I called the place I got them from and thinking they might have a wiring diagram for the three tube setup since I couldn't get them to work with 4 tubes. The guy basically blew me off and told me to call an electrician that he couldn't tell me how to wire them. I then told him, well there is a wiring diagram on the ballast for the 4 tube wiring but I wanted to go the 3 tube route and he said we don't have a wiring diagram for the three tube setup. I then asked him if the ballast I bought could be used both ways and he said yes, yes they could........But he couldn't send me anything on how to wire it that way.

Long story short I'm still holding the bag and still can't figure out why they wont work. I'm now thinking the electrical connectors that are in the fixtures are the wrong type for the ballast I have. My question is should the connectors be shunted or non shunted connectors for the parallel wiring diagram that is displayed on the ballast?

Signed In the dark

 

[The Cobbler]

googled it and found this diagram https://www.google.ca/search?q=t8+b...=14zqWLXNBqPEjwS9vqSIDA#imgrc=4O3d4qVX0wNKWM:

 

[Zexx]

I am assuming you have white, black, 2 yellow, 2 red, and 2 blue wires on your 4/3 bulb ballast. To wire for 3 bulb have 1 yellow go to both pins on one end of a bulb, other yellow to both pins on one end of the other 2 bulbs. On the opposite sides of the bulbs have both red go to both pins on 2 bulbs, one wire per bulb, one blue go to both pins on the end of the last bulb. Cap the 2nd blue wire as it is unused. Black and white are your power.

 

[cybrdyke]

I'm now thinking the electrical connectors that are in the fixtures are the wrong type for the ballast I have. My question is should the connectors be shunted or non shunted connectors for the parallel wiring diagram that is displayed on the ballast?

In this case, doesn't matter if you have shunted or non-shunted sockets.
Cap off one blue lead to run just 3 lamps.
If you previously had T12's, there could be a jumper wire or two in the fixture that need to be removed.
The mounting screw is sometimes a ground path. Be sure the hole it goes into isn't filled with gunk or paint and that it seems to be biting on metal.
Good luck,
CD

 

[Bert_]

We really need some more information. I would assume you have a instant start, parallel lamp ballast. If so the above posts pretty much sum it up. But there are other types out there and we need to know what you have to give you pertinent info.

 

[BillK]

Have you tried the ballast manufacturer's web site ? They usually have all of the wiring diagrams there.

 

[mx842]

googled it and found this diagram https://www.google.ca/search?q=t8+b...=14zqWLXNBqPEjwS9vqSIDA#imgrc=4O3d4qVX0wNKWM:

I've already been there and found this one along with a bunch of others. The 4 tube setup like is in that drawing is how it's wired now and it still wont work. But thanks anyway it was worth the try.

 

[mx842]

In this case, doesn't matter if you have shunted or non-shunted sockets.
Cap off one blue lead to run just 3 lamps.
If you previously had T12's, there could be a jumper wire or two in the fixture that need to be removed.
The mounting screw is sometimes a ground path. Be sure the hole it goes into isn't filled with gunk or paint and that it seems to be biting on metal.
Good luck,
CD

I didn't think it would but that's all I could think of that could be wrong. Some of these fixtures I want to leave as three tube but I want to add extra sockets to a couple of them to make them four tube fixtures where I can use the extra light. I thought about the ground thing maybe some of the problem because when I first wired it up the bulbs would light the way I had it wired but they were about half lit; meaning they were on but were not bright like they should be and when I touched a bulb that one would get brighter. So I pigtailed a another ground wire from ground lug over to one of the mounting studs for the ballast but it didn't make a difference.

I also found while I was messing around with the wiring that something is weird because I can hook up the black and white wires while the power is on and it lights up nice and bright but as soon as I cut the switch off and turn it back on it pops the GFI breaker that feeds this circuit. I'm thinking now that I just may have a bad ballast out of the box. I think I'll try another one just to see what happens. Thanks for your help.

 

[mx842]

We really need some more information. I would assume you have a instant start, parallel lamp ballast. If so the above posts pretty much sum it up. But there are other types out there and we need to know what you have to give you pertinent info.

Bert, that's what I have. I'm thinking I have a bad ballast or maybe these instant start ballast and The GFI plug that feeds this circuit doesn't like the instant start circuitry of the ballast.I hadn't thought of that because I had two other older t 12 fixtures on that circuit and they worked ok.

 

[mx842]

Have you tried the ballast manufacturer's web site ? They usually have all of the wiring diagrams there.

I called them but they were not very helpful but thanks anyway.

 

[mx842]

In this case, doesn't matter if you have shunted or non-shunted sockets.
Cap off one blue lead to run just 3 lamps.
If you previously had T12's, there could be a jumper wire or two in the fixture that need to be removed.
The mounting screw is sometimes a ground path. Be sure the hole it goes into isn't filled with gunk or paint and that it seems to be biting on metal.
Good luck,
CD

Referring to the shunted and non shunted connectors does it matter if I ever decide to switch over to LED bulbs?

 

[cybrdyke]

I didn't think it would but that's all I could think of that could be wrong. Some of these fixtures I want to leave as three tube but I want to add extra sockets to a couple of them to make them four tube fixtures where I can use the extra light. I thought about the ground thing maybe some of the problem because when I first wired it up the bulbs would light the way I had it wired but they were about half lit; meaning they were on but were not bright like they should be and when I touched a bulb that one would get brighter. So I pigtailed a another ground wire from ground lug over to one of the mounting studs for the ballast but it didn't make a difference.

I also found while I was messing around with the wiring that something is weird because I can hook up the black and white wires while the power is on and it lights up nice and bright but as soon as I cut the switch off and turn it back on it pops the GFI breaker that feeds this circuit. I'm thinking now that I just may have a bad ballast out of the box. I think I'll try another one just to see what happens. Thanks for your help.

What this tells me is that it's mis-wired. See, the lamps are OK, because you've proven that they CAN come up to full brightness. And the ballasts are OK because you've provent that they CAN fire the lamps all the way up. So, there's just a wiring issue that wont allow them to operate properly.
Keep looking....you'll find it.

 

[cybrdyke]

Referring to the shunted and non shunted connectors does it matter if I ever decide to switch over to LED bulbs?

If you install LED tubes that run on the ballast, you'll be OK.

If you decide to bypass the ballast, you have 2 options.
1) if you use the style that has the wiring on one end, like most of them do, then you'll need non-shunted sockets.
2) if you use the style that has one wire to each end of the tube, then it doesn't matter which socket you have.

Lets' clarify a couple of things to make this easier....
What type of lamp and ballast were in these fixtures before you started?
What is the part number of the ballast you are installing?

 

[mx842]

If you install LED tubes that run on the ballast, you'll be OK.

If you decide to bypass the ballast, you have 2 options.
1) if you use the style that has the wiring on one end, like most of them do, then you'll need non-shunted sockets.
2) if you use the style that has one wire to each end of the tube, then it doesn't matter which socket you have.

Lets' clarify a couple of things to make this easier....
What type of lamp and ballast were in these fixtures before you started?
What is the part number of the ballast you are installing?

So I guess what you are saying that you don't need a ballast if you go to LED bulbs?

The fixtures were originally 3, tube running off of a 277V ballast wired in series. The ballast I bought were 120V/277V ICN 4P 32N, multi voltage instant start ballast and they are for parallel wiring that work with 3 or 4 bulb fixtures.

All that doesn't matter anymore anyway, I figured out what was wrong. The fixture I was working with I wanted to be able to turn on by itself and not with two other lights mounted on next to them. These other lights were on switches that could be turned on and off from either the front or the back of the shop. I had a 20A circuit that I use to operate two chain lifts in the center of the building that was real close to this new fixture that I wanted to work by itself. I already had two, 2 tube fixtures using this circuit along with the two chain lifts but they were old and got to where they wouldn't work half the time so I took them down and put this new fixture up to replace them. They were old T 12 fixtures and I guess the GFI plug that operated this circuit didn't mind those older fixtures. It didn't like these new instant start fixtures though and kept tripping when it was turned on. I just pulled 3 wires off one of those other two lights and now all three come on at the same time. I'll run a new circuit to this one fixture when I have the time to make it work by itself but for now I'm good. Thanks for all you guys help with this I was about to go nut's over this one. I just needed to give it a day or two rest so I could figure this out and you guys were right there to help. Thanks Everbody!!

 

[Falcon67]

>So I guess what you are saying that you don't need a ballast if you go to LED bulbs?

This. you can get bypass bulbs at 1000bulbs.com for around $9 each. I plan on this update when our new trailer gets here - gut the fixtures and use just LED T-8 style bulbs.