# Simple electrical q - GFI outlet and a switch **URL:** \ **Category:** Factual Questions\ **Created:** [March 15, 2006, 4:52pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476 "2006-03-15T16:52:18Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [March 15, 2006, 4:52pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/1 "2006-03-15T16:52:18Z")
Hi Folks~ I have an extraordinarily simple installation project, one that after reading and reading (print and online), I’m somewhat confident I could safely do on my own—but I have yet to see this configuration directly described. As a new homeowner (and consequently new to home wiring) I want to give electricity as much respect as I possibly can—hence I’m reluctant to do this unless I am COMPLETELY confident I can do it right. Anyway… I am about to install a new waste disposer. I have 12/2 cable coming from the panel to the cabinet below the sink. I have a GFI receptacle to be mounted under the sink, and a single pole switch to be mounted on the wall. I want to plug the disposer into the receptacle (so it can easily come out if there is a problem) and turn it on and off via the switch (it is not a batch feed model). Wiring an outlet and a switch shouldn’t be a problem, but it seems that GFI outlets are wired somewhat differently, and nothing has taken me through the process with one. I understand the basics of a GFI receptacle (i.e. live/load distinction) but am wary of merging the two types of instructions. Could anyone point me in the right direction? Thanks! Rhythmdvl ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 15, 2006, 5:14pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/2 "2006-03-15T17:14:19Z")
Yes, you could wire the switch to turn the GFCI on and off–I have a similar setup in my bathroom. There was no outlet near the sink, but there were lights over the vanity controlled by a switch near the door. I simply wired from the lights to the GFCI, so the GFCI and the lights both are off when the wall switch is off. But, if I were doing your installation, I’d leave the GFCI energized at all times, and connect the downstream terminals of the GFCI to an undersink outlet through the switch. The switch would control the underswitch outlet to turn the disposer on and off, and the GFCI would protect BOTH the switch and the disposer. Your way, the switch would be unprotected. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 15, 2006, 5:15pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/3 "2006-03-15T17:15:38Z")
> [@Q.E.D.](#): > > The switch would control the underswitch outlet… Err…you know what I mean. :smack: ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [March 15, 2006, 5:42pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/4 "2006-03-15T17:42:49Z")
Q.E.D. is describing the best plan and the wiring is straightforward. ```auto powerbox ==== line GCFI load ==== switch ==== extra outlet ==== disposal ``` This would give you a total of four outlets, with two always hot and two controlled by the switch. You could arrange for three hot and one on the switch, if you prefer, by snapping off a tab on the “hot” (i.e. brass) side of the outlet and changing the wiring slightly. Instructions will be included with new non-GCFI outlets. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [March 15, 2006, 6:09pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/5 "2006-03-15T18:09:17Z")
You are both over-complicating things with the multiple outlets and ignoring the National Electrical Code. Code calls for dishwashers and disposers to be on their own dedicated 20-amp circuits. A GFCI is \*not \* required for either. Ideally, each dedicated circuit will terminate in a single receptacle (not the usual duplex type) so only the disposer or dishwasher can be plugged in. See NEC section 210-8(a)6 for the boring details. Check with your city/county to see if they have any particular requirements. I know you’re on the other side of the country, but [this page](http://www.californiaelectrician.net/kitchen/101-kitchen.html) gives some insight into regional variations in kitchen wiring. Bring a magnifier - their text is tiny. Failure to do this right and to code could bite you down the line when you want to sell and someone points out wiring that’s not done properly. FWIW, kitchens have developed some rather detailed requirements. It’s not at all uncommon for a kitchen remodel to involve running eight new circuits - minimum 2 circuits for countertop outlets, plus dedicated circuits for dishwashers, disposers, built-in microwaves, refrigerators, trash compactors, etc. Plus big items like electric ranges or wall ovens. A growing trend is to run a new feeder circuit and install a sub-panel in the pantry to hold all the new circuit breakers. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 15, 2006, 6:53pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/6 "2006-03-15T18:53:50Z")
> [@gotpasswords](#): > > Code calls for dishwashers and disposers to be on their own dedicated 20-amp circuits. This is not necessarily correct: > [@](#): > > **Question 6.** Do a dishwasher and a garbage disposal have to be on separate circuits? Can you have any lighting outlets on with these? — E.F. > > **Answer 6.** Reference 110.3(b) [NEC 2002], Installation and Use. “Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.” Thus, if the manufacturer specifies a separate dedicated circuit for a dishwasher or garbage disposal, then the response is yes.If a separate circuit is not indicated, then we must review Section 210.19(A)(1), General. “Branch-circuit conductors shall have an ampacity not less than the maximum load to be served. Where a branch circuit supplies continuous loads or any combination of continuous and noncontinuous loads, the minimum branch-circuit conductor size, before the application of any adjustment or correction factors, shall have an allowable ampacity” equal to or greater “than the noncontinuous load plus 125 percent of the continuous load.” I would not consider a dishwasher or garbage disposal to be a continuous load. IOW, the OP needs to RTFM ;). I’m also assuming that the OP wishes to use the outlet for other things in the area near the sink besides the disposal, in which case a GFCI is required. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [March 15, 2006, 6:59pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/7 "2006-03-15T18:59:45Z")
> [@gotpasswords](#): > > You are both over-complicating things with the multiple outlets and ignoring the National Electrical Code. I’m allowed; it’s not my nation. 😃 ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [March 15, 2006, 7:00pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/8 "2006-03-15T19:00:55Z")
> [@Q.E.D.](#): > > Yes, you could wire the switch to turn the GFCI on and off–I have a similar setup in my bathroom. There was no outlet near the sink, but there were lights over the vanity controlled by a switch near the door. I simply wired from the lights to the GFCI, so the GFCI and the lights both are off when the wall switch is off. > > But, if I were doing your installation, I’d leave the GFCI energized at all times, and connect the downstream terminals of the GFCI to an undersink outlet through the switch. The switch would control the underswitch outlet to turn the disposer on and off, and the GFCI would protect BOTH the switch and the disposer. Your way, the switch would be unprotected. This is the correct method. It is quite possibly an electrical code violation to have electrical components that a person can touch ahead of the GFI. The object of GFI’s in kitchen, exterior outlets and bathrooms it to protect outlets and switches in places where there is water and therefore the possibility of a really good ground to a person. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [March 15, 2006, 7:12pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/9 "2006-03-15T19:12:00Z")
If I understand correctly, you’re saying that because the switch is part of the hot line powering the GFI, it is unprotected (GFI-wise). Not so good when potentially wet hands will be reaching for the switch. If I can be pedantic about this (because electricity scares the crap out of me), this is the way I should do this (this is coming from an independent, new 20 amp/ 12/2 circuit from the sub-panel in the basement). **For the cable coming from the circuit panel to the GFCI receptacle:** [ul] [li]_Green_ wire (ground) to the green terminal on the GFCI receptacle (as part of a pigtail)[/li][li]_Black_ wire (hot) to the hot/brass/line terminal of the GFCI receptacle[/li][li]_White_ wire (neutral) to the silver/neutral/line terminal of the GFCI receptacle[/li][li]_The GFCI outlets are always on._[/li][/ul] \*\*From the GFCI to the ordinary receptacle \*\* [ul] [li]_Green_ wire (ground) to the green terminal on the ordinary receptacle (as part of a pigtail)[/li][li]_White_ wire (neutral) from the GFCI neutral/silver/load terminal to the silver/neutral terminal on the ordinary outlet.[/li][li]_black_ wire (hot) from the GFCI hot/brass/load terminal spliced (w/ a wire connector) to the white (but marked/flagged as hot) wire going to the switch. This does not connect directly to the ordinary receptacle, and the splice sits in the receptacle box (if there is room. If not, I will install a junction box). [/li][/ul] **From the ordinary receptacle to the switch** [ul] [li]_Green_ wire (ground) to the green terminal on the switch (pigtailed to the ground on the ordinary switch).[/li][li]_Black_ wire (hot) from the ordinary receptacle to a brass/hot terminal on the switch[/li][li]_white_ wire (neutral) does not connect to the switch—it (as above) is connected to the silver/neutral/load terminal of the GFCI receptacle. [/li][li]The ‘ordinary’ receptacle is controlled by the switch, protected by the GFCI, and powers the disposer. [/li][/ul] Or, if I understand **gotpasswords** post and links correctly, the GFCI isn’t required per se, and protecting the switch is not imperative. If so, I can skip a trip and effort to wire an ‘ordinary’ receptacle, and do as follows: **For the cable coming from the circuit panel to the receptacle:** [ul] [li] _Green_ wire (ground) to the green terminal on the receptacle (as part of a pigtail)[/li][li] _White_ wire (neutral) to the silver/neutral/line terminal of the GFI receptacle [/li][li] _Black_ wire (hot) spliced (w/ a wire connector) to the white (but marked/flagged as hot) wire going to the switch. This does not connect directly to the receptacle, and the splice sits in the receptacle box. [/li][/ul] **For the cable connecting the receptacle to the switch:** [ul] [li] _Green_ wire (ground) to the green terminal on the switch (continuing from the pigtail connected to the receptacle’s ground terminal)[/li][li] _White_ wire (marked and flagged as hot at both ends) spliced (w/ a wire connector) to the black wire that connects directly to the circuit panel, connected at the other end to a brass terminal on the switch. [/li][li] _Black_ wire connects to the brass/hot/line terminal of the receptacle and connects to a brass terminal of the switch. [/li][/ul] Again, please excuse my pedantry in this, but my common sense/caution/paranoia wants to be as mollified as possible. Thanks, Rhythmdvl ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [March 15, 2006, 7:15pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/10 "2006-03-15T19:15:28Z")
Oh, FWIW, the new outlets will be under the sink, in the bottom corner behind the disposer. We’ve no intention of plugging _anything_ else into the outlet other than the disposer. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [March 15, 2006, 7:20pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/11 "2006-03-15T19:20:57Z")
> [@Rhythmdvl](#): > > If I understand correctly, you’re saying that because the switch is part of the hot line powering the GFI, it is unprotected (GFI-wise). Not so good when potentially wet hands will be reaching for the switch. > > Thanks, > > Rhythmdvl Yes. In San Bernardino County, CA all electrical devices within reach of the water, like the wash basin, must be on a GFI protected circuit. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [March 15, 2006, 7:27pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/12 "2006-03-15T19:27:48Z")
> [@David Simmons](#): > > Yes. In San Bernardino County, CA all electrical devices within reach of the water, like the wash basin, must be on a GFI protected circuit. Come to think of it, whether or not the code actually _requires_ a GFCI is irrelevant to the following thought—if it can’t hurt, and even if it only offers a marginal level of safety, that’s still marginally better. So GFCI/extra outlets it is (if the above wiring description is correct, that is). Rhythm ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 15, 2006, 7:32pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/13 "2006-03-15T19:32:30Z")
> [@Rhythmdvl](#): > > If I understand correctly, you’re saying that because the switch is part of the hot line powering the GFI, it is unprotected (GFI-wise). Not so good when potentially wet hands will be reaching for the switch. This is all correct. The GFCI is not required by the NEC for an in-sink garbage disposal. Nor is it prohibited, so I would err on the side of safety and include one in the circuit, anyway. This has the added advantage of providing a convenient protected outlet near the sink, should the need arise for it provided, of course, that the disposal manufacturer’s instructions do not call for a dedicated circuit. ---
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [March 15, 2006, 10:38pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/14 "2006-03-15T22:38:53Z")
> [@Rhythmdvl](#): > > Oh, FWIW, the new outlets will be under the sink, in the bottom corner behind the disposer. We’ve no intention of plugging _anything_ else into the outlet other than the disposer. GFCI outlets have to be tested periodically and it’s not unknown for them to occasionally trigger themselves for no particular reason, requiring a reset. So the GFCI outlet is going to have to be accessible. Given the annoyance of having to occasionally reset the GFCI outlet and the incredibly small chance of getting a shock from flipping a switch with wet hands, I personally wouldn’t (and didn’t) bother. However, the final arbiter is your local electrical inspector. You could stop by and ask him what he thinks. One alternative that hasn’t been mentioned is using a circuit breaker with a builtin GFCI. ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [March 15, 2006, 10:50pm UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/15 "2006-03-15T22:50:19Z")
I don’t ever recall hearing about protecting a switch with GFCI, only outlets. My house has a light over the sink with a nearby switch, the electricians who re-wired the kitchen recently said nothing about making it GFCI, even while putting GFCI protection in the outlets that share the box with said switch. Making this switch GFCI protected requires that you put a second outlet under the sink, just for that purpose, which seems a bit overkill. Can’t put it over the counter since you’re now hooking up a disposal to a counter receptacle circuit, which is probably a violation of some sort. Personally, I’d stick with just making the disposal outlet GFCI, it goes beyond what code requires, and does not force you to install unnecessary outlets, only installing a different sort of outlet. On a more general note, my electricians cautioned against too much GFCI protection. GFCI is subject to nuisance trips, which is very bad news on refrigerator circuits and sump pumps, where the nuisance trip won’t be immediately apparent, until you have a major problem. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [March 16, 2006, 2:05am UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/16 "2006-03-16T02:05:53Z")
I know I am a little late to the party here, but I mounted [this guy](http://www.insinkerator.com/isejsp/product/accessory.jsp?id=32&template=hhd) to run my disposer. It offered me a couple of advantages 1. I didn’t have to cut in an additional box 2. I run my insta hot off the same circuit (the two outlets are set up either or) 3. No worries about getting a shock with wet hands. ---
**Author:** ![KCB615](https://avatars.discourse-cdn.com/v4/letter/k/ea666f/32.png) [@KCB615](https://boards.straightdope.com/u/KCB615)\ **Post date:** [March 16, 2006, 2:18am UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/17 "2006-03-16T02:18:05Z")
One could always install a GFI breaker for that line in the service panel and eliminate all of the what-comes-before-what problems… ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 16, 2006, 3:52am UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/18 "2006-03-16T03:52:05Z")
> [@Cheesesteak](#): > > I don’t ever recall hearing about protecting a switch with GFCI, only outlets. This is true, but the setup we were describing has the switch protected as a matter of course, not necessity. The idea was to have an always-on GFCI outlet near the sing area feeding a switched undersink outlet for the disposal. The switchy doesn’t _need_ protection, but in this case it just happens to be that way. I like **Rick** ’s idea, too, especially since the OP said he wasn’t planning on needing an extra outlet, anyway. ---
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [March 16, 2006, 4:17am UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/19 "2006-03-16T04:17:23Z")
> [@Q.E.D.](#): > > This is true, but the setup we were describing has the switch protected as a matter of course, not necessity. The idea was to have an always-on GFCI outlet near the sing area feeding a switched undersink outlet for the disposal. Code sort of frowns on this. The idea is that if you’ve got your waffle maker and percolator plugged into the outlet and hit the disposal, you’ll probably blow the circuit breaker. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 16, 2006, 4:23am UTC](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476/20 "2006-03-16T04:23:43Z")
> [@Finagle](#): > > Code sort of frowns on this. The idea is that if you’ve got your waffle maker and percolator plugged into the outlet and hit the disposal, you’ll probably blow the circuit breaker. Well, that’s what the circuit breaker is _for_. 😉 Anyway, as I posted previously, the NEC only cares that the disposal be on a dedicated circuit only if the manufacturer’s instructions specifically call for such. As long as the ampacity conditions are met, you’re good, as far as code is concerned. [Next page](https://boards.straightdope.com/t/simple-electrical-q-gfi-outlet-and-a-switch/348476.md?page=2)