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#182388 - 11/25/08 12:06 AM More than two 15A rated switches on 20A circuits
Niko Offline
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Registered: 08/17/06
Posts: 356
Loc: Campbell, CA
Table 210-21(B)3 allows 2 or more 15 & 20A receptacles on 20A circuits. what does the code say about 2 or more 15A rated switches on a circuit that is protected by 20A breaker?

Thanks for your comments.
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#182389 - 11/25/08 01:08 AM Re: More than two 15A rated switches on 20A circuits [Re: Niko]
gfretwell Offline


Member
Registered: 07/20/04
Posts: 9039
Loc: Estero,Fl,usa
Switches are really supposed to be rated for the load so a 15a switch on a 20a circuit is not a problem if it is a 15a (or less load). More of an issue, generally, is whether a switch is motor rated when it is a motor load. You have to watch out for this when you are using a snap switch for things like pool pumps and big "whole house" fans.
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#182393 - 11/25/08 05:52 AM Re: More than two 15A rated switches on 20A circuits [Re: gfretwell]
IanR Offline
Member
Registered: 12/06/04
Posts: 328
Loc: Palm Bay FL USA
"Switches are really supposed to be rated for the load"
So what about a 15A switch controlling a duplex receptacle, with a 20A breaker? Where you really can't determine what the load may be.
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#182397 - 11/25/08 08:55 AM Re: More than two 15A rated switches on 20A circuits [Re: IanR]
renosteinke Offline
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Registered: 01/22/05
Posts: 5316
Loc: Blue Collar Country
I'ts quite simple, Ian.

Let's assume you have that switch operating a space heater, or other heavy load. The switch simply won't last very long, and stop being a switch. There might not even be any fireworks; the contacts just won't close anymore, and you get to replace the switch.

That's the whole point to the 'motor rating' idea. Motors, and some other loads, require a lot more than the rated current under specific circumstances .... so the switch will need to be able to handle those moments.

Once again, we come up against an example where 'trade practice' has been decades ahead of 'code.' In this instance, I'm referring to the trade proctice of separating the lighting circuits from the receptacle circuits, and using 15 amp circuits for lighting.
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#182413 - 11/25/08 03:09 PM Re: More than two 15A rated switches on 20A circuits [Re: renosteinke]
pdh Offline
Member
Registered: 01/20/05
Posts: 354
The one switch failure I ever had was a "failed to OPEN" scenario. But that switch was very much abused.
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