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Discussion Starter · #1 ·
Hey all, I've been having some issues lately with a building where I installed some T8 fluorescent light fixtures. I've gotten called back twice now with ballasts failing, (six total after only 4 months since install) and I'm trying to figure out what might be causing it. Here are the details:

Fixtures: 8' 4-lamp T8 vaportights, electronic multi-volt ballasts (running on 120V). 12 total fixtures on circuit. Ballasts are Osram (Sylvania).

Building: 60'x120' animal barn at the local zoo. These lights are in the keeper's access hallway, lighting an area 10' wide by the full 120' length. Panel is in the middle, and lights are on a set of 3-way switches at each end, at entrances. Surface-mount pvc conduit running between them, all weathertight covers, etc. (wash down rated). I installed the whole electrical system in this place, including the feeders, which came out of a MDP in the administration building, so I'm confident the power is not dirty.

Checked voltage at a couple of the fixtures, including the last in line, under load, and got a steady 115 volts, so voltage drop doesn't seem to be a problem.

Lights were mounted with the included hangar brackets, so they are spaced off the ceiling, don't see heat being an issue. (It is not air-conditioned, but the ceiling is insulated from the attic space)

Neutral line was good, no crossed neutrals with any other circuit, and no loose connections.

As far as I know, they are not excessively switched either, although I have no way of knowing on average how often they are flipped on and off. Keepers are usually there the whole morning for chores, and lights stay on until they are done and out.

There is one other lighting circuit for the animal stalls, which has (15) 4' vapor tight T8 fixtures, and (12) 2' vapor tight LED fixtures. No issues with those fixtures.

I can see only two differences between that circuit and the one with the problems: Problem circuit also has a pair of 70W LED wall packs hooked up to it, one at each end, to light up the entrances outside (each on self-contained photocell). Could that somehow be interfering with the ballasts, causing them to fail? Or, the other difference is that the 8' fixtures were shipped separately from the other fixtures, but same supplier (Lithonia), and maybe they just have a batch of poorly made ballasts?

Any tips, or ideas where to look from here are much appreciated.

JLK
 

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Do you have a part # on the ballasts?
 

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Wasn't there a similar thread a month or two ago? Anyone remember the thread
name or OP?
P&L
 
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thers that short term memory thing again! remeber the thread but not the details:(
 

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OP: You've wiped out most of the usual suspects.

I'd double check the length of your circuit -- three-ways really increase the voltage drop -- lest you find that your neutral is actually undersized -- it might have needed a #10... or some such.

You're going from your MDP to $ 1 then travellers then $ 2 then off to the light string... that's hundreds of feet in this instance.

I've seen such long runs trip up many an electrician.

#12 is fine out to 120 feet... from there on, you have to back down the load.

Even #8 is sometimes required. (!)
 

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Hey all, I've been having some issues lately with a building where I installed some T8 fluorescent light fixtures. I've gotten called back twice now with ballasts failing, (six total after only 4 months since install) and I'm trying to figure out what might be causing it. Here are the details:

Fixtures: 8' 4-lamp T8 vaportights, electronic multi-volt ballasts (running on 120V). 12 total fixtures on circuit. Ballasts are Osram (Sylvania).

Building: 60'x120' animal barn at the local zoo. These lights are in the keeper's access hallway, lighting an area 10' wide by the full 120' length. Panel is in the middle, and lights are on a set of 3-way switches at each end, at entrances. Surface-mount pvc conduit running between them, all weathertight covers, etc. (wash down rated). I installed the whole electrical system in this place, including the feeders, which came out of a MDP in the administration building, so I'm confident the power is not dirty.

Checked voltage at a couple of the fixtures, including the last in line, under load, and got a steady 115 volts, so voltage drop doesn't seem to be a problem.

Lights were mounted with the included hangar brackets, so they are spaced off the ceiling, don't see heat being an issue. (It is not air-conditioned, but the ceiling is insulated from the attic space)

Neutral line was good, no crossed neutrals with any other circuit, and no loose connections.

As far as I know, they are not excessively switched either, although I have no way of knowing on average how often they are flipped on and off. Keepers are usually there the whole morning for chores, and lights stay on until they are done and out.

There is one other lighting circuit for the animal stalls, which has (15) 4' vapor tight T8 fixtures, and (12) 2' vapor tight LED fixtures. No issues with those fixtures.

I can see only two differences between that circuit and the one with the problems: Problem circuit also has a pair of 70W LED wall packs hooked up to it, one at each end, to light up the entrances outside (each on self-contained photocell). Could that somehow be interfering with the ballasts, causing them to fail? Or, the other difference is that the 8' fixtures were shipped separately from the other fixtures, but same supplier (Lithonia), and maybe they just have a batch of poorly made ballasts?

Any tips, or ideas where to look from here are much appreciated.

JLK

I would try to find out why you only have 115v. You should be up around 120v to 124v.
 

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Discussion Starter · #11 ·
Hey guys, thanks for the responses. The lighting supplier is involved, they've given me replacements to put in, but one of the replacements the first time around was one of the fixtures that went dark this second time around, so I am not 100% confident the problem is getting solved. That's part of the reason I'm looking around for other causes (it feels like a cop-out to blame it on poor quality, although at this point I think it can be a legit reason.)

I do have 120V at the panel, so there is a little voltage drop going on. But the reason I didn't suspect it too much is that (1) The other circuit has the same distances to cover via the 3-way switches, and those fixtures have had zero problems; and (2) the supposed operating range of these ballasts is 110 and up (according to the packaging).

MikeFL: I will get a part number for you later today. If I haven't been committed to the local insane asylum before then. ;-)

JLK
 

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Have you checked connections to that circuit? Could be something loose somewhere.
 

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Don't discount poor quality. Last week we relamped a shop with t 12 HO fixtures, a bunch of ballasts had to be changed as well. the boys opened a case of lamps and put them in the fixtures, turned them on and not a single lamp worked. put old lamps in and they worked. went back to supplier, got another box of lamps, same thing. grabbed t lamps we had at the shop, they worked fine. went and got a third box of lamps, different lot # and they worked perfectly. All brand new Sylvania junk
 

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Don't discount poor quality. Last week we relamped a shop with t 12 HO fixtures, a bunch of ballasts had to be changed as well. the boys opened a case of lamps and put them in the fixtures, turned them on and not a single lamp worked. put old lamps in and they worked. went back to supplier, got another box of lamps, same thing. grabbed t lamps we had at the shop, they worked fine. went and got a third box of lamps, different lot # and they worked perfectly. All brand new Sylvania junk
That's a new low !
 

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A year or two ago we installed 24 4 bulb troffers on a job and had at least three ballasts that fail within a week of operation. They were Philips ballasts and the supplier replaced them for us.
 

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Discussion Starter · #17 ·
Osram Quicktronic: QHE 4x32T8/UNV ISN-SC

They have "inherent thermal protection", but that basically just means it will kick out if it gets overheated, and come on again once it's cooled, right?

I checked a few of my connections, but there are a couple more junction boxes I could pop open.

In my head I keep coming back to the fact that there is another circuit that has 15 fixtures, all with 2-lamp T8 ballasts, that has no problems. I'm really starting to think that these 4-lamp ballasts are just crap.
 

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Osram Quicktronic: QHE 4x32T8/UNV ISN-SC

They have "inherent thermal protection", but that basically just means it will kick out if it gets overheated, and come on again once it's cooled, right?

I checked a few of my connections, but there are a couple more junction boxes I could pop open.

In my head I keep coming back to the fact that there is another circuit that has 15 fixtures, all with 2-lamp T8 ballasts, that has no problems. I'm really starting to think that these 4-lamp ballasts are just crap.
I just dont know why it but it did ring the bell not too long ago because I am just got done reballast a bunch of them just couple days ago.,,

The QHE 4X32T8/UNV ISN - SC .,,

that I did ran 6 of them couple days but the instering twist which I do not know if you ran in tandam type or single 4 lamp strip or whatever it is .,,

I ran that in Tandam and it was not working too well because of distance of the ballast to the furthest tombstone .,, even thru I know I did check the manufacter listing on maxuim distance and I was Way under that limit so that is not a issue but the workmanship on four lamp ballast is not the best what I got in my area .,, two out of six did not work properly so I was forced to resort to swap to double two lamp ballast that I do know it never fail on me .,, right now I am waiting for reply from my rep in differnt island so it will be a matter of time before I get anything.
 
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