OT shop lights

This is way off topic, but I thought somebody in this group would have the answer.

My garage/aircraft manufacturing/maintanence facility has three banks of 8-ft fluorescent lights wired on a single switch. They are cheap ones from Lowe's hardware, maybe eight years old.

They will no longer come on, but all six tubes glow faintly when you throw the switch.

Is this a bad ballast? Are they like old Christmas tree lights where a single bad bulb will take out the whole string?

I really don't know where to begin troubleshooting. I could just replace them all fairly inexpensively (significantly cheaper than calling an electrician), but if somebody could offer suggestions for repair I'd appreciate it.

I have the same thing and if one bulb is bad it will sometimes cause both to quit working. I also lost 1 ballast out of 8 the first six months so it could be a ballast. I'm not much of an electrician but some here are and can probably be of much more help.

I do know one thing my friend who is an electrician put in the latest 6 bulb high efficiency fluorescents in his shop and I may be changing some of mine out. They are bright! HE also got a rebate from the electrical company on them because of the efficiency.

Sounds like a wiring problem to me

flyeyes said:

My garage/aircraft manufacturing/maintanence facility has three banks of 8-ft fluorescent lights wired on a single switch. They are cheap ones from Lowe's hardware, maybe eight years old.

They will no longer come on, but all six tubes glow faintly when you throw the switch.

Click to expand...

James,
Is this 3 separate fixtures? If so, they should all not have failed at the same time with the same symptom. This would indicate a wiring problem.

Sounds like they could be too cold. Where are you located?

Mark

Mark Burns said:

James,
This would indicate a wiring problem.

Sounds like they could be too cold. Where are you located?

Mark

Click to expand...

That's what I'm thinking, but I'm wondering about a bad ballast or something. I'm reasonably competent with most wiring/electrical stuff, and totally understand incandescent lights, but the fluorescent tubes might as well be magic as far as I know.

The behavior is exactly the same as the "too cold" fluorescent symptoms, but with OAT around 87 degrees as I type this, I tend to discount that hypothesis;-)

They seem to be wired in series; the romex cable leaves the switch and disappears into the first fixture, reappears and goes into the second, and so on. It terminates in the third fixture. Since all six tubes glow faintly, I don't think the circuit has failed open.

I kind of doubt a single bulb failure would cause this, as I have seen fluorescent fixtures with a single bad bulb, and the fellow glowing normally. Maybe cheap fixtures are wired differently?

I know there is somebody in the RV-o-sphere who is familiar with this symptom and its cure.

Six 8ft tubes driven with a single ballast sounds like an unusual Lowes purchase, but there are such fixtures.

I have a lot of fluorescent lights at my store. The practical approach is to take one new tube and swap it for each old tube in turn. Take a good look at the contacts at each end of the lamp fixtures as you go along. If that doesn't find a bad tube or bad contact, replace the ballast.

Back in business



Although the lights all failed simultaneously, I started swapping out bulbs.

replacing a single bulb in #2 resulted in that light working normally (both tubes) but #1 and #3 still were Tango Uniform.

1 bulb in #1 fixed that fixture, but it took both bulbs in #3.

Now all seem to be working normally.

I think I've learned that cheap fixtures are wired so that a single bulb will kill both sides, and that fluorescent tubes have feelings and will commit suicide if their neighbors die.

Thanks for the suggestions.

I bought some of the really bright ones from Home Depot. I'm really happy I got them. Light up the big hanger really well with two of those, and a couple of old fixtures. I think they are 120W tubes, pricy.

The cheapys mean you get what you pay for...