Conventional Fixtures - PAR 56 ground wire

[Radiant]

We use PAR 56s for house light, cheap ADJ brand, and they are giving me many fits. I've been replacing the sockets as needed, as the insulation flakes off rapidly. But now I'm seeing several that have absolutely destroyed ground wires - insulation burnt off, tarnished green copper, frayed and broken strands. The ground wire has a round lug on the end, held to the can by a bolt and nut. The bolt and nut are locked together so tightly that I can't unscrew it. I don't have this issue with the 2 spare cans that were never installed in the ceiling. I end up just ripping the bolt out of the flimsy aluminum can. I'll post pictures tomorrow, as I'm going to rewire a couple more.

I have two questions. Firstly, what in the heck is making the ground wire corrode like that? I understand the insulation flaking off - they're cheap cans, and I'm accustomed to their short lifespan. But I just don't understand the copper wiring being in such awful condition.

Secondly, I want to make sure I replace the ground wires correctly. I salvaged some high-temp wiring from a half dozen 360Qs I rewired a few months ago. Tonight I bought an assortment of ring terminals - I think the wiring is 16 AWG, but my bases are covered if I'm wrong. And I bought 6-32 x 1/2 zinc coated screws and nuts. Does this seem appropriate? The sockets are Sylvania 36" whip, sheathed in Production Advantage's Flex-Guard FPE sleeve.

[Footer]

Is it humid? Your in Oklahoma, so there is no ocean near by. How long is the light on a day? Whats the conditions like?

[Radiant]

It's pretty humid these days. Oklahoma sees the effects of all four seasons - hot summers, cold winters. I'm not too sure how long the lights are on during the week. I'd wager that some days they're on for 12 hours, other days not at all. They are mounted to the roof structural beams. We've long had heat issues with them.

[JD]

Two things:
1) Metal + Heat + Humidity = big time corrosion! Also why the screws won't come out.
2) I suspect these are mounted vertically and therefore the heat builds up at the top where the wiring is.
Replace your sockets with something like these: PAR-1 PAR56 PAR64 Mogul End Prong Lamp Socket (Sylvania / Osram)

They come with a 36 inch whip. If you are cutting off the wires and only using the base (not recommended) then the left over wire is defiantly high temp. A better solution would be to not have any connection in the fixture, and just use high temp Teflon or silicon with fiberglass sheath. The less connections the better.

[TimMiller]

I have learned that crimp terminals will melt in pars quite easily. I found some high temp insulated crimp terminals a while back that were rated for 150 deg C. In which the aluminum will probably begin to warp first. But the standard home depot stuff does not hold up. I once had a can that someone crimped and then wrapped the crimp in e-tape, well the thing got hot and melted the crimp and caught the e-tape on fire. Its not good to have a flame comming out of one of your cans on the DS truss.

[Footer]

Originally Posted by TimMiller

I have learned that crimp terminals will melt in pars quite easily. I found some high temp insulated crimp terminals a while back that were rated for 150 deg C. In which the aluminum will probably begin to warp first. But the standard home depot stuff does not hold up. I once had a can that someone crimped and then wrapped the crimp in e-tape, well the thing got hot and melted the crimp and caught the e-tape on fire. Its not good to have a flame comming out of one of your cans on the DS truss.

Just blame it on the pyro guys...

12 hours a day... ya, you might want to invest in some higher quality cans from the get go. The ones you purchased are meant to be on for a few hours a day, max. Put in high quality whips, and that should help ya.

[derekleffew]

Originally Posted by Radiant

...Firstly, what in the heck is making the ground wire corrode like that? I understand the insulation flaking off - they're cheap cans, and I'm accustomed to their short lifespan. But I just don't understand the copper wiring being in such awful condition. ...

Heat; and galvanic action among dissimilar metals. Aluminum can, Electro-tin plated terminal, copper wire, and whatever the material(s) from which the nuts and bolts are made.

[Radiant]

Rats, now I need to learn metallurgy too?!?! I thought mine would be an uncommon situation due to the severity, but apparently not.
JD, you are correct, they are dead hung straight down. Heat has been an issue with these cans from day one. Literally, glass lenses were separating from their reflectors before the installation was complete. And those are the very whips I got, too.

Footer4321, a few years ago I learned, firsthand , about electrical tape in PARs. (Had one go up in flames at a wedding rehearsal, the flame didn't go out after the breaker tripped, and it was inaccessible without a ladder.) I wish we could get better cans, along with many other things, but the budget is what it is.

Here's what I ended up doing today. I rewired 3 PAR 56s and one PAR 64 this way. You can see in the end of the can where we've ripped open the air vents to allow more circulation. Let me know if this passes muster.

[Footer]

Your still going to have issues with the plastic melting. The air vents will help, but your going to have issues. They do make terminators without the plastic, or you could remove the plastic. Grounds don't need to be insulated.

[Radiant]

Originally Posted by Footer4321

Your still going to have issues with the plastic melting. The air vents will help, but your going to have issues. They do make terminators without the plastic, or you could remove the plastic. Grounds don't need to be insulated.

Good call. I'll snip off the plastic in the future.