DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (https://www.diychatroom.com/)
-   Electrical (https://www.diychatroom.com/f18/)
-   -   12 AWG circuit, 14 AWG cable for the last load -- a switched light (https://www.diychatroom.com/f18/12-awg-circuit-14-awg-cable-last-load-switched-light-657211/)

ElectricIQ 04-12-2019 06:14 PM

12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
1 Attachment(s)
Hi, I have a double ganged light switch+receptacle box on my kitchen counter wall. The light switch is on a 15A living room circuit and controls an overhead kitchen sink light, not GFCI protected. The receptacle is on a 20A kitchen circuit and is GFCI protected. I don't like this setup, because 1) I almost forgot to switch off the living room circuit breaker while working in the box; 2) I'd prefer having the light switch be protected by the GFCI circuit as well since it's close to the sink. I'd like to feed the light through the 20A GFCI circuit instead, and cap off the 15A/14AWG wires. The receptacle is the last one on the GFCI protected 20A/12AWG circuit, is it ok to add the switched light to this last receptacle through the existing 14/2 romex for the light?

What does the current U.S. NEC code say about my situation? thanks


Attached drawing describes the situation.

curiousB 04-12-2019 06:19 PM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
No. Cable ampacity must be equal or greater than the branch breaker.

ElectricIQ 04-12-2019 06:35 PM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
OK, thanks. Are switches on kitchen counter walls required to be GFCI protected?

Yodaman 04-12-2019 06:35 PM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Maybe separate the double box into separate single boxes.

joed 04-12-2019 06:44 PM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Quote:

Originally Posted by ElectricIQ (Post 5812759)
OK, thanks. Are switches on kitchen counter walls required to be GFCI protected?

No they are not.

Quote:

I'd prefer having the light switch be protected by the GFCI circuit as well since it's close to the sink. I'd like to feed the light through the 20A GFCI circuit instead
Can't do that. Kitchen counter receptacle can't have lights on the circuit by code.

Arrange the two breakers so they are beside each other and install a handle tie so they both go off together.

ElectricIQ 04-12-2019 06:46 PM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Thank you for the definitive answers. I will just leave it be then.

7635tools 04-13-2019 07:19 AM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Quote:

Originally Posted by curiousB (Post 5812747)
No. Cable ampacity must be equal or greater than the branch breaker.



So does that mean all the commercial buildings with 14 gauge, 3 wire whips to the lay in fixtures on 20 amp breakers are wrong.


Sent from my iPhone using Tapatalk

rjniles 04-13-2019 08:03 AM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Quote:

Originally Posted by 7635tools (Post 5812925)
So does that mean all the commercial buildings with 14 gauge, 3 wire whips to the lay in fixtures on 20 amp breakers are wrong.


Sent from my iPhone using Tapatalk

As long as the whip was manufactured as part of the fixture it is complaint. It is a listed assembly, no different that a light fixture using 16 gauge wires that connect to a 15 or 20 amp circuit.

7635tools 04-13-2019 09:07 AM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Quote:

Originally Posted by rjniles (Post 5812977)
As long as the whip was manufactured as part of the fixture it is complaint. It is a listed assembly, no different that a light fixture using 16 gauge wires that connect to a 15 or 20 amp circuit.



So all the fixture whips that are bought or made with 14 gauge wire are wrong if they weren’t supplied with the fixture?


Sent from my iPhone using Tapatalk

rjniles 04-13-2019 09:48 AM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Quote:

Originally Posted by 7635tools (Post 5813015)
So all the fixture whips that are bought or made with 14 gauge wire are wrong if they weren’t supplied with the fixture?


Sent from my iPhone using Tapatalk

Correct, they are not tested as a listed assembly. They can be used on a 15 amp circuit.

Sent from my Moto E (4) Plus using Tapatalk

BluegrassGuy 04-13-2019 01:17 PM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Quote:

Originally Posted by ElectricIQ (Post 5812769)
Thank you for the definitive answers. I will just leave it be then.


Yes. The way it's wired is exactly the way it's supposed to be wired. Just be careful when working on electricity, and be sure test ALL wires in a box for power before working on anything in that box.

Shadow99 04-13-2019 01:55 PM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Quote:

Originally Posted by 7635tools (Post 5812925)
So does that mean all the commercial buildings with 14 gauge, 3 wire whips to the lay in fixtures on 20 amp breakers are wrong.


Sent from my iPhone using Tapatalk

There are tap rules for lighting. So you can run a smaller conductor from a junction box to the fixture, even if it isn't part of the listed fixture.

You can't do it from the switch thou.

rjniles 04-13-2019 03:58 PM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Quote:

Originally Posted by Shadow99 (Post 5813151)
There are tap rules for lighting. So you can run a smaller conductor from a junction box to the fixture, even if it isn't part of the listed fixture.

You can't do it from the switch thou.

Tap rules are beyond the scope of most DIYers experience and are very easy to misunderstand and misuse. The OPs situation is not within the scope of an allowable tap.

huesmann 04-15-2019 08:10 AM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Quote:

Originally Posted by Yodaman (Post 5812757)
Maybe separate the double box into separate single boxes.

Sounds to me the issue isn't the boxes, it's his brain forgetting that the light and outlet are on separate circuits. Unless you mean to further separate the switch and outlet in some fashion to distinguish one from the other, like actually moving the separate boxes a few inches apart.

RAL238 04-15-2019 12:28 PM

Re: 12 AWG circuit, 14 AWG cable for the last load -- a switched light
 
Just use a Sharpie and write a note on the yolks of the switch/receptacle, or on the back side of the cover plate that says "2 circuits in this box!" Or label them as "Ckt 1" and "Ckt 2" or whatever


All times are GMT -5. The time now is 07:46 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.