The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Topic Options
Rate This Topic
#182388 - 11/25/08 12:06 AM More than two 15A rated switches on 20A circuits
Niko Offline
Member
Registered: 08/17/06
Posts: 358
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.
_________________________
Be kind to your neighbor, he knows where you live

Top
2017 / 2014 NEC & Related Books and Study Guides
#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: 9066
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.
_________________________
Greg Fretwell
Top
#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: 326
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.
Top
#182397 - 11/25/08 08:55 AM Re: More than two 15A rated switches on 20A circuits [Re: IanR]
renosteinke Offline
Cat Servant
Member
Registered: 01/22/05
Posts: 5305
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.
Top
#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.
Top

Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box

Recent Posts
Looking for older post
by sparkyinak
Today at 12:27 AM
License exam
by TRUE POWER
Yesterday at 11:33 PM
Members: Non-Members: Did you know?
by Admin
Yesterday at 02:34 PM
Safety at heights?
by HotLine1
01/21/17 08:51 PM
International Wire Colour Codes
by Texas_Ranger
01/21/17 03:29 PM

Who's Online
1 registered (sparkyinak), 108 Guests and 11 Spiders online.
Key: Admin, Global Mod, Mod
New in the Gallery:
Desk-mounted "power-board"
Top Posters
gfretwell 9066
Trumpy 8560
pauluk 7693
HotLine1 6833
sparky 5545
Member Spotlight
Member Since: 08/01/07
Posts: 62

ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals