PAR 64 re-wiring


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“I have a par 64 at my youth group and the wiring other side is completely burned through, melted, ,dead. like, the wire itself i think was burned through, or oxidized to the point of breaking. To fix it, what do i need to do? I was thinking just replace the wire, but now that you point out all these rules...1) where can I get the wire 2) do i need to replace the entire ceramic lug, which would have the leads on it? 3) is it worth it ?” - JahJahwarrior

First, given the info on “What is wrong with this picture” page 6, the NEC code applications, the use of a PAR fixture for a church related youth group would fit within the more broad classification of assembly hall necessity for compliance over that of that legit theater necessities for the wiring of it. Given this, it’s never bad to comply with the highest standards for what’s the proper way to do something.

There is but one main question given this “burnt up wiring” that needs to be answered before it can be described how to re-wire such a thing. This question revolves around the lamp base/porcelain socket itself. Is the Porcelain itself in good shape, or is it also in need of replacement?

A good test for any PAR 46 thru PAR 64 fixture is if the lamp socket will support the weight of the bulb when suspended by it. If the lamp can’t be picked up and held by the lamp socket, the tension within the lamp holder as the NEC calls it is insufficient to conduct the current to the lamp. Much less, it’s easy for the socket to fall off the fixture’s lamp base.

Pick the lamp up with the socket and look at it for frayed wires, melted wires, arched contacts, broken porcelain etc. in deeming if the the lamp base is in good condition. Once this is determined, write back and there is two or more ways to go with the solution.
Ok - my simple question for the day when reading this. You say "arched" contacts and my initial thought was it was a typo and was meant to read "arced" as in pitted or otherwise damaged through a bad electrical connection.

However, I have seen several lamps on which the contacts are bent in a arch like shape (always away from the centre) and I am wondering if this is significant of anythig like over heating.

Yes - I know there is no such thing as a silly question but upon the completion of writing this I am now begining to wonder ?
Arcs in a concave shape are called pitting. They are a little more easy to deal with than welds and blobs of material on the surface that can be ground down than protected against the shortfalls of grinding, but in pitting, once smoothed over present less surface area in the end.

Both are normally caused by over heating not necessarially from the lamp's heat although it can factor in. It's more caused by bad tension on the lamp by it's lamp base which will cause it to arc as it's trying to conduct.

When you see a lamp with such things and discoloring, also check the lamp base. You should be able to pick up the lamp by the lamp base when it has the proper amount of tension.

Put a bad lamp into a good base and it's going to destroy the good lamp base. Put a good lamp into a bad lamp base and it will do the same.

Depending upon the type of lamp there is ways to fix or at least remove the bad parts to some degree than re-surface coat it, but normally once you remove the nickle plating on a lamp's pins, it won't have the proper heat resistance or even conductivity across the pin. In the case of a PAR 64 lamp, since it does not have nickle plated pins, you should be able to remove and clean the surface of the pin for what good it does. Unfortunately the lamp base itself if in good condition only has so much area in contact with the lamp's pins and this is no doubt the area that will be already bad on the lamp. I have heard of a copper based deoxident being used to sort of fill in the holes but I have my doubts as to the usefulness of such a thing.
Ship has asked me to post the following images to demonstrate why he was asking for more information from the person who asked the initial question regarding re-wiring a PAR 64 can.

What one person determines as being safe is not always safe. Some of the question of the day posts (from which this topic has been born) has illustrated this quite nicely.

Ship will be along to discuss the images, but in the meantime, I would welcome anyone to comment on the pictures that Ship has provided:




oh my... just cut off the old cable and put a new one on and use good wire nuts and electricly tape.

Look under gx16d and click on par 1 lamp base. This is what I recommend using as the best lamp base on the market.

Point of theabove photos is that this is what someone else interpeted as safe and in good shape up until it failed. We all have different interpetations on what's safe based upon our training and experience. I certainly did some very unsafe things as I was learning. Now I even look at stuff coming straight from the factory and can about tell how long such wiring will last. Hmm, let's put heat shrink to cover the ring terminals on jumper cables attached to 650w lamps...

On the photos:
Note the cable tie holding together the lamp base - that is until it becomes brittle with heat and the porcelain pops open in exposing conductors. Right about the time you reach in there to spin the bottle.

Note also the yellow wire nut no doubt using the electrical tape to hold it on. Or the red one that melted down after probably touching the lamp.

Wire nuts are not rated for use inside of a lighting fixture - not high temp enough - nor is the electrical tape. Not to mention both the wire nuts - especially the red one are many times larger than rated for use with the wire gauge of a lampholder. Not only would they as any wire nut simply fall off the wires, but in this case it would not even do a good job of binding the wires.

Anyway, it's from one of a few fixtures that a local high school sent for me to repair. I kept the assembly and worry about the stuff they did not send me.

By the way, these photos were put into the wrong post - should have been in "PAR parts." Thanks anyway Mayhem.
Ship said:
By the way, these photos were put into the wrong post - should have been in "PAR parts." Thanks anyway Mayhem.

Ooops! Have placed them in the Par Parts thread as well.
ship said:
Anyway, it's from one of a few fixtures that a local high school sent for me to repair. I kept the assembly and worry about the stuff they did not send me.

So - this is why so many students are complaining about the lack of fixtures within their schools!
I do admit that the last selection of five 360Q's sent to me to just change the shutters as not needed for a while, it took me at least two months to get them out the door by X-Mass. But I was also busy and the customer was in no rush.

When it comes to fixing Lekos on the other hand as opposed to a six foot stack of multi-cable, I would always prefer to fix the Leko. It's thus normally the carrot on the stick in getting the other stuff done. Unfortunately of late, that other part has been growing faster than my ability to fix it thus eventually with reminders by the sales rep, I knocked them out last week. 15min each there abouts, not much of a reward for doing other things.

In the case of the PAR 64 fixtures, there was not much that was not wrong with the cheap DJ cans from screws put on with nut to the inside of the can so it's ensured of falling on an audience member insetad of being noted, to the wiring in general that was abismal. Plus I had to re-mount them to the lamp bar in a other than hack way.

Lost money on that deal in that we had to figure my time at about half just to get some figure that would work. Still the customer got a safe product and will be back for more - hopefully at normal man-hours.

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