Quote:
Originally Posted by ibpooks  Your relay looks just fine. The oxidation comment makes no sense to me; metal lasts longer when there is no current running through it. |
The guy at Grainger said that when current is present on the load side, a momentary arc created during open/close will "clean" the contact surfaces. That is also the reason why there are different contact surface metals/alloys. I did some more research and it sounds like he is right, although it still may not be a concern for me. He recommended either a reed relay (the contacts are in a tube filled with an inert gas) or a mercury wetted relay (doesn't have oxidation problems). However, I haven't been able to find one that is enclosed and pre-wired like the one in the link above.
Since it's not a critical circuit (I'm only monitoring the gen startup/shutdown times), I will probably take my chances with one from Grainger.
Thanks,
Ira