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Cleaning Allen-Bradly switch contact modules?

BadDog

Stainless
Joined
Mar 27, 2006
Location
Phoenix, AZ
I finally broke through my mental block (or whatever you call it when you just can't seem to get started on a project) and started my staged RPC tonight.

I've accumulated some "nice" 800T series AB switches in NO, NC and NO/NC Mushroom configs including pilot light; all very cheap $10 for a box full at surplus/scrapper. But I have a couple of questions and/or problems.

First, I've not found any clear indication of the voltage expectations of the lamp. Haven't look that hard yet, but it wasn't obvious.

Second, and more important; checking continuity across the contactor blocks (particularly of the push-pull mushrooms), some of them don't consistently make a good connection. There is some visible dirt in there. I see how the module comes out, but it appears not to come apart without damage. What's the best way to clean these? Just the spray in contact cleaner?

If I can get these switches to work, I'm going to "bread board" (on plywood) the whole thing tomorrow just to make sure all is well before I go making permanent mounts in my nice NEMA enclosure. Assuming the switches are good, I've got everything but the heaters and run-caps so things should go pretty smoothly (I hope).
 
It's my weekend, so I can't run over and check the 800t box for comparison, BUT I believe, that many of the AB illuminated buttons are not voltage specific. SOME come with a transformer and ARE voltage specific. Most of those are 120 (or some other voltage ) in and 24, 12, or 6 out. They will say on the module. Otherwise it depends on the bulb. Most bulbs have a number printed on the glass, or etched on the base. I think the 755's are 6volt, and we have two boxes of them at work because I've mixed the numbers in my head when ordering. (oops)
Maybe it's the 757's that are 24volt? :confused: I don't remember... Google monster or a Sylvania / GE catalog are my life savers. I think the GE one has cross references? If you can't tell it's been a while.

I've never tried to clean the contacts on those, because I've always had a box or two to dig a replacement out of. I'm curious of any one has a slick trick to open them? If you do get them open a small brush will help when removing the carbon, just contact cleaner is much slower. Just don't bend the contacts, wipe the brush across them, don't scrub.

Have fun,
Doug S.
 








 
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