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!
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.
Q.E.D. is describing the best plan and the wiring is straightforward.
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.
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 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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
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.
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.