Touching the lamps contacts


Active Member
IS it possible that the oil from our skin also can cause electricity to arc across the conctact pins of lamps and damage both the socket and the lamp from a short circuit, becuase 3 of our source four pars have fried sockets and lamps that have toasted contacts, from what is beleived to be caused by short circuited lamps due to people touching the lamps contacts
As far as I know, arcing is caused solely by an improperly seated bulb in a fixture. Always make sure the bulb is down as far as possible before plugging it in. Also, whenever you change a bulb be sure to check for the arcing so that you don't ruin another bulb.
Hmm, we have similar problem. We always assumed that the contacts were corroded. But the contacts on the fixturea nd the lamp were blackened. I'm not sure if you have the same problem, but it you're in a pinch, acetone or battery cleaner will make the fixture work for a few days before it gets all nasty again, otherwise, just buy a few replacement contact parts for the source fours, and you should be okay.
also you can get a retrofit kit that puts the retainer clip on older fixture that dont have one. I always have extra leads on hand for s4's.
Sweat is the major offender when touching things. Since sweats is salts and water, it could cause a small increase in the resistance of the connection which could lead to arcing. It also could promote corrosion and so this might be what is happening. Alternatively, the base has been subjected to arcing and so is creating problems for the connection. This can also cause the lamp to go bad. Ship has written on this in the past. Blackened pins are telltale evidence of arcing. Arcing is basically caused by electricity needing to jump an air gap to get to the bulb. It increases the resistance of the connection and this can get to the point where it will not conduct. Arcing can be studied in more detail in this previous question of the day thread on Hot Patching. The problem is the same, whether it be plug and socket or lamp and socket.
We just send the fixutre sockets out for reapair every time this happens but next year when i am head of the "lighting" department in our schools tech club, i will specifically tell people NOT to touch the contacts, it is pretty much common knowledge that sweat is damaging any were on a lamp apart from the ceramic heat sink
I've had that problem with older S4's. The lamps are not seated tight enough. The person changing the lamp needs to make sure the lamp is all the way in. Once they arc they create carbon build up. Once this happens it is harder to get the lamp to seat all the way. Also, you burn our the sockets and have to replace them. I think the model is TP22 about $13.00 US.
I just saw listed thru one of the stagehand or tools for techies type websites something I believe called a HPL lamp seating device. There is a few websites like these out there that sell for the most part gadgets for techies but I don't remember which one I saw it on. I was searching for a Socapex cable tester at the time.

OK, I invented such a lamp seater in concept but did not refine it or pattent it. In my case it was a short length of 1" schedule 40 pipe and a rubber mallet. What I saw on the website was a wee slight much better in refinement. I know there is a post somewhere about me using such a technique on new S-4 Pars a few years back.

They can at times be tight when new - this as opposed to the ones that at times that are loose. It's a cast aluminum as a part. Give me 600 new ones and 10% will be too tight and 5% will be too loose. Give me old ones and 10% will be too lose to the extent the lamp simply falls out this by way of both lamp base sockets stretching out or the aluminum support for it going out of whack, and them that were too tight becoming normal for the most part.

I kind of recommend this HPL lamp seating tool as a sort of widget of the year type of thing. Not cheap but as opposed to the bag over the lamp, this will allow you to fully seat the lamp without breaking the bulb or pulling out a section of pipe and hammer. (yea I broke a few lamps in doing so.) Anyone wish to do a search and provide a link for this red tool I'm thinking of?

Anyway, on the lamp bases, most all pins have a nickel plating on them which is corrosion and or finger ****ing resistant. No, don't be eating that Hershie bar with the same hands as you are playing with the pins, but it's not otherwise noted that the pins on any lamp have problems with contact with one's dirt on the hands. Probably not a bad idea not to overtly touch the pins but for the most part it should not cause problems.

What's presented above is probably very accurate in resistance but the amount of resistance it adds to a pin would be fairly minute as compared to a just plain bad lamp base or bad lamp stuck into a good base.

Your problems with lamps and bases are probably un-related to this touching of the pins - more just the lamp base socket going bad in stretching out. they get old and go bad with time.

Too bad ETC doesn't just sell the no doubt $1.00 each crimp terminal lamp base socket you can re-crimp onto your already installed heat wire. Probably a liability type of thing in providing a proper crimp to the wire. The price of a replacement whip/socket is a wee bit expensive given what it is. But this is ETC.

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