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DPDT Relay

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BrownOut

Banned
I'm sure I'm not the first to ask this: I'm using a DPDT relay that has contact rating of 10A. I want to wire the two "poles" together for 20A operation. Has anyone ever done this? Are there any "gotchas" to my plan?

Thanks.

EDIT: Really, I'm only trying to get 13A, but using 20A for margin and any derating.
 
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Sceadwian

Banned
Yeah, a big one, the contacts won't make or break at exactly the same time so during switching you'll violate the relays ratings, if there's an induction involved the relay will die a very early death.
Why not just get a 20amp relay? They're not so expensive as to justify using a 10amp relay in this manner.

EDIT: 13amps is only slightly over the 10amp rating of the relay it might work okay in that manner. It MIGHT be okay, but I honestly wouldn't trust it if it's connected to something important.
 
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BrownOut

Banned
I'm just prototyping something, and these are the realys I have on hand.
 

Birdman Adam

New Member
I've done that to a few DPDT relays in some older projects, they've been working good for a few years now.. I wouldn't use it as a long term solution though.
 

Sceadwian

Banned
I'm with birdman, just use em. If it's a commercial device or something you want to be highly reliable find a replacement later. Or test your luck and just use as is. It could go the exact opposite way for you, there could be some weird harmonic oscillation that sets up with the pair of interrelated contacts an external RLC network that cause it to make the rest of the circuit go up in flames, who knows. Just watch it very carefully when you first try it out.
 
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RCinFLA

Well-Known Member
Better if you can restrict the high (or higher currents) to the engaged state. The rest state has less contact pressure and slower return from engaged state as it is only the return spring pulling it back.
 

Sceadwian

Banned
But less bounce? That's the thing I've always found evil about relays was contact bounce. Depends too much on physical systems which are never modeled.
 
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