LED corncob bulbs keep coming loose

[KyleFowler]

We did a job replacing some Metal Halide bulbs in decorative pole lights with LED corncobs. The problem is that in a year or so the bulbs work loose and burn up themselves and the socket (the voltage is 277v and the sockets are base down). We think the problem is that the heavier corncobs are slowly working loose when the poles wiggle in the wind? Lol. Replacing the sockets isn't helping. I also think that since the corncobs run cooler they aren't getting "fused" in the sockets like metal halides tend to.

I did a search of this forum to see if anyone else has had this problem and didn't find anything. The safest solution I read on Google seemed to be to try steel wool to rough the bulb threads up a bit. Anybody have other ideas?

 

[LarryFine]

A rubber band around the top of the screw shell, where it will engage the inside of the socket, but not the threads.

 

[synchro]

A rubber band around the top of the screw shell, where it will engage the inside of the socket, but not the threads.

Maybe an appropriate diameter and thickness O-ring could be used in the same manner.

 

[jimport]

Haven't seen that issue yet with horizontal corn cobs in pole lights yet.

I will say that we are not seeing anywhere near the advertised lifespan on some led products. Anyone else seeing the same?

 

[ptonsparky]

One of our suppliers quit stocking one brand because of the failures. The mfg and supplier are honoring the 5 year warranty but it’s a pain having to charge for replacing a fixture that didn’t last.

 

[brantmacga]

I've seen this very same thing with the larger lamps installed vertically in enclosed signs. In that particular case, someone install a lamp that was far too large for the application and we installed smaller lamps and haven't seen the issue repeat yet.

The new Satco LED lamps come with a bracket and small steel cable w/ a caribiner that you can tie off that will keep it from A) falling out of the fixture if it comes loose & B) turning out of the lamp holder if tied off appropriately.

 

[hillbilly1]

I've seen this very same thing with the larger lamps installed vertically in enclosed signs. In that particular case, someone install a lamp that was far too large for the application and we installed smaller lamps and haven't seen the issue repeat yet.

The new Satco LED lamps come with a bracket and small steel cable w/ a caribiner that you can tie off that will keep it from A) falling out of the fixture if it comes loose & B) turning out of the lamp holder if tied off appropriately.

I've got some GE's that have the same thing, figured they must be a problem, or they wouldn't have done that.

 

[b1miller]

3 years ago we replaced 36 400W Halide bulbs with equivalent LED corncob bulbs at the museum I volunteer at. Rated at 277V and we removed the ballast as required. We have had about a 25% failure rate to date and while our local supplier has been great about honoring the 5 year warranty we have to rent a lift each time to allow the bulb replacement.

 

[hillbilly1]

We were doing a test retrofit for a major customer, five different brands. I would ask each engineer, from that manufacture that came out to the job site what the initial failure rate we could expect. Of course, all of them said there would not be an initial failure rate. Well, the initial failure rate right of the box was around 2-3%, which was what I figured. One in particular had a higher rate than the others because the factory workers were shorting out the drivers by not lining up the mounting holes.

 

[hillbilly1]

You might try some Loctite 222. It’s low strength, so you should be able replace the lamp. It’s made for soft metals such as brass.

 

[sameguy]

Bend the socket to add more retention, like a pleat or nip the edge.?

 

[KyleFowler]

You might try some Loctite 222. It’s low strength, so you should be able replace the lamp. It’s made for soft metals such as brass.

I thought about loctite but wondered if it would cause resistance?

 

[LarryFine]

Bend the socket to add more retention, like a pleat or nip the edge.?

Good idea. Just a slight twist wit needle-nose.

 

[hillbilly1]

I thought about loctite but wondered if it would cause resistance?

You would only need a small drop just at the top where it still makes contact, don't coat the whole base.

 

[KyleFowler]

thanks everyone for the replies, I think we are going to try slightly bending the sockets because that requires the least work/materials (when considering having to go buy stuff) but i thought everyone had good ideas!