sde

We recently completed a lighting retro-fit from t-12 to 120v instant start electronic ballasts and 32w t-8 tubes with reflector kits and new tomstones. We have been back many times to change bullb and tombstone ends that are completely melted together. contacted manufacture and they say bulbs are not inserted properly. I sent them tombstones that were melted with the slot of the tombstone exactly horizontal. currently we have changed roughly 100 ends and 200 bulbs. Wholesaler says bulbs or ballasts are not the problem. Any ideas?

frank

Just a thought. Are the new tubes EXACTLY the correct length,


Frank

HighWirey

SDE,

Lighting retrofit here was hot several years ago. Last sizeable project was a T-12/T-8 Phillips, 277 retro, 9600 ea Motorola electronic 4 lamp ballasts. Never had a problem with tombstones. Problem here was managing the waste stream. Subject for another post.

Lamp length seemed to be identical T-12 to T-8.

Would like to know what you find out.

Merry Christmas Everyone, and Best Wishes

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DBack Elec

Interesting never had one do that, but would think it has to do with the connection. That would be my guess.

Shawn

I just recently ran into that same problem after a retro fit had been done at one of my job sites. The tombstone had melted all the way to the reflector. I just assumed the bulb wasn't seated properly at the time. Maybe the manufacturers do have a problem with a certain design?

pbelectrical

Are the pins of the new tubes spaced the same distance apart as the old ones. The connection between the tube pins and the tombstone contacts is achieved via pressure, if the new pin spacing is narrower than before they may not be making proper contact. Loose contact equals hot joint, which in turn causes the contact to become looser, which in turn gets hotter................ You get the picture. May also be caused if the pins are a different diameter.


Regards,

Peter Brown.

Jim Port

T-12 and T-8 pin size and spacing are supposed to be the same.

kbsparky

Electronic ballasts can operate at speeds as high as 25,000 Hz. That's a lot more than the old 60 Hz we are used to.

The connections MUST be tight in those sockets, or else you will have high-speed arcing occurring within them, causing the meltdowns you are observing.

Me thinx you have cheep sockets. Try another brand.

HighWirey

"Wholesaler says bulbs or ballasts are not the problem"

What else do you expect him to say? He don't want that liability. I hope your wholesaler also provided those tombstones!

The quorum of the forum here seems to point to flakey tombstones

Sounds like another good EC is about to take it on the chin.
Good luck, Sir.

Merry Christmas Everyone, and Best Wishes

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randomkiller

I had a similar problem a couple of years ago and got no where with the supplier. I thought the metal used in the tombstomes was the issue. We changed the most problematic ones to another brand and had no further melt downs.

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Joefixit2

Besides what the others have said, what type of environment are these fixtures located in? I have seen meltdowns in meat processing areas where the humidity is so high during washdowns that water drips from the fixtures. I believe the excessive moisture degrades the socket to pin connection and causes arcing.

jbfan

I have the same thing happen where I work. I have 3500 lamps in one warehouse and every year when we relamp, I replace hundreds of tombstones. Another year or so I will have them replaced. This only happens in the warehouse with the locking tombstones. The retrofits in the office areas have not had this problem.

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sde

Thanks for the input. I greatly appreciate it. I sent us energy sciences some of the tomb stones. They replied on 12-5-07 that the tomb stones were fine They are saying that possibly the bulbs are not seated properly or the new tomb stones do not line up correctly.I was back at the job from hell yesterday and replaced 5 tomb stones. The worst of this was the 60 bulbs also. I am starting to think maybe it is crappy bulbs or bad ballasts. I called the wholesaler back and reamed him a new one He said they would contact bulb and ballast manufactures today. havent heard anything yet. I will post somthing when I get a reply.

jrclen

Interesting thread, I'll be interested in what you find. I've never had a problem with tombstones. Sounds like a nightmare.

bigredc222

Is it possible that one of the guy's on your crew is wiring them wrong? How well do you know the guys' that did the work? If you rule them out. Then the test will be to see what happens with the replaced tombstone. If the replaced one doesn't melt with the same ballast and lamp, then you can rule them out. If it happens again, then it's the ballast or lamp. I've probably put in 10s of thousands of lamps. I've had very few issues with lamps, or tombstones. It's the ballast or the guy that wired it 99% of the time.

John Valdes

How common is it to retrofit fixtures. I have never retrofited one in my career. We always put up new fixtures.

bigredc222

I haven't done it in ages. 15-20 years ago. We got hooked with Honeywell. We did collages, and hospitals. I hated it. Your arms are over your head the whole day. It was a lot of night work. We put in a lot of motion sensors also. I've done thousands. I can't remember the last time I've done one now. I guess there must still be some lights out there that are still T12 lamps. Those old ballasts could last 30-40 years sometimes. The electronic don't last a fraction of that.

bigredc222

Keep us updated on what the outcome is.

jrclen

I've did a few retrofit jobs when the t8 lamps and electronic ballasts came out. I didn't enjoy the call backs for bad ballasts. It wasn't a particular ballast problem, just that the new ballasts don't seem to last. New fixtures seem to have the same problem.

sde

Well, I was supposed to have a meeting with the ballast rep on 12/18/07. I finally got some help from the bigger boss at the whole sale house that I boght the lamps and ballasts from. He seemed to think it was the ballasts, not the ends or lamps. I got a call on 12/17/07 from the wholesaler stating that they found the problem. It seems that the lamps that were supplied to me were made for magnetic ballasts not electronic ballasts. There have been at least two other jobs that have had melting tombstones. The wholesaler investigated the time frame. So now I have to go back to the job from hell and replace 3000 light bulbs and god knows how many tombstones that are melted. Thanks for the input, I greatly appreciate it.