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metarchaeon t1_iy8sj5n wrote

Are you planning on adding plugs to both the new dishwasher and the disposal? I'm not sure what the advantage is over hardwired. The box inside the old dishwasher is a valid junction box.

As to you wiring, you don't need to run the 12-3 wire to the switch, just wrap the ends of the white wire (that you have capped on both end) with black tape and use it.

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dominus_aranearum t1_iy90q3b wrote

>As to you wiring, you don't need to run the 12-3 wire to the switch, just wrap the ends of the white wire (that you have capped on both end) with black tape and use it.

No longer up to code. All switches must have a neutral.

While it will technically work, might as well wire it properly if it's being done at all.

Switches with lighting loads now require the neutral. Wouldn't apply in OP's case.

Edit: I was wrong. 404.2(C)(7)

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metarchaeon t1_iy91mjf wrote

Where do you connect a neutral to a switch? Honest question.

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TonyFugginMontana OP t1_iy94eo3 wrote

That's just it, it doesn't connect anywhere, it just gets capped. Apparently to accommodate the possibility of future retrofitting for "smart" switches, which do require a neutral, per other comment above.

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Masterandslave1003 t1_iy9gjct wrote

Ha, I bought some smart switch for my old house and learned this the hard way! The neutral apparently carries a tiny bit of current that the smart switch uses to keep its settings of something like that.

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WittyMonikerGoesHere t1_iy9h7vq wrote

Believe it or not, the neutral carries exactly the same current as the hot, when connected in a circuit.

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KapJ1coH t1_iy9kyiv wrote

Wait a second, if I don't have a neutral, can I just connect hot to both hot and neutral terminal? I'm not very knowledgeable in jome electricity so I might be wrong.

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bluGill t1_iy9og18 wrote

This is no longer allowed by code, but it used to be that instead of a neutral people would use the neutral as the switched hot side and no neutral would go to the switch at all. This saves some money, and copper is not cheap.

Hot and neutral go from the breaker to the outlet, the neutral wire is connected to the neutral size of the outlet. Hot is connected to a second wire that goes to the switch, then the neutral from that second line is connected to the other side of the switch and then to the hot side of the outlet. When doing this you were supposed to paint the white wire black (or red) so everyone knew it wasn't neutral, but often this wasn't done.

This is not connecting hot and neutral together. It is taking a wire that is normally used for neutral and using it for hot in a situation where the neutral wire wouldn't be used anyway.

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emcturkeyshirt t1_iy9rzxm wrote

That is up on black back on white rule…. And there is no neutral involved. You’re making the white wire hot……………..hence phasing it black.

Switching a neutral will never work…. In you single phase home…. It just won’t really work.

On a three phase system, well breaking or switching a neutral will create a dangerously unbalanced load. Possibly resulting in blowing up your lights and electronics.

Don’t ever switch a neutral. You can use the white wire as hot in one specific scenario. But it is NOT a neutral.

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WittyMonikerGoesHere t1_iy9p6vq wrote

On a normal switch, there is no neutral terminal. The three connections are for line in, line out, and ground. Neutrals are bridged in a standard wiring situation.

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KapJ1coH t1_iy9z144 wrote

Oh I was talking about a smart switch, sorry if I wasn't clear.

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MeshColour t1_iy9jt6e wrote

Believe it or not, a "dumb" switch uses no power, so has no requirement to be hooked up to the neutral. And yes zero would equal zero, which is why neutral isn't required for the switch itself

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WittyMonikerGoesHere t1_iy9ouir wrote

Not to operate, no. Some are saying codes require it now. A "dumb" switch only interrupts the circuit. You could wire the neutrals to the switch instead of the hots, and it would work exactly the same. Shouldn't because changing a light bulb would then carry the possibility of electrocution, but could.

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emcturkeyshirt t1_iy9ro1b wrote

Believe it or not, if you were to break a neutral or switch it…… bad things will happen.

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spyrosj t1_iy9k6zw wrote

Not an electrician but I think the reason the neutral is there so that the connected smart switch can complete the circuit and get power. An inline switch just breaks the electrical connection. And like /u/WittyMonikerGoesHere, the neutral carries the same load as the hot since its necessary to complete the circuit.

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hardMarble t1_iy9lzpi wrote

100%, the switch's brains couldn't be on without having some current go to the light, if there is no neutral in the box

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bluGill t1_iy9oo1f wrote

There are dumb switches with built in lights (expensive, but I recommend them) that really should have a neutral.

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[deleted] t1_iy9vkle wrote

[deleted]

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bluGill t1_iybvthl wrote

Unless the switch has a neutral so they don't have to leak power down what they pretend is an off circuit.

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I_AM_NOT_A_WOMBAT t1_iy9cf9t wrote

When you use any kind of specialty switch, like (obviously not relevant here) a motion sensor, timer, etc. a neutral is best. There are motion sensors that pull a bit of current through the circuit itself, but they are terrible at best and often don't work with LED lighting, which is also code now.

I suspect the code mentioned is meant to prevent shoddy sparkies from lazily grabbing neutrals from nearby circuits, which can result in shared neutrals (ask me how I know this).

I can't honestly think of a reason why you'd use anything other than a dumb toggle switch for an under-sink cutoff for a DW/Disposal, but it's probably easier and safer to just say "all switch locations need a neutral" than to specify "except under kitchen cabinets where the switch is only used for an appliance cutoff".

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the_pinguin t1_iy9j5cf wrote

Motion sensors use the ground wire to complete a circuit in the absence of a neutral wire. It's not ideal, but it does work.

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I_AM_NOT_A_WOMBAT t1_iy9muy0 wrote

True, but older homes often don't have ground wires either. Ours built in the late 50's didn't have grounds.

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the_pinguin t1_iy9naj8 wrote

Oh I know. My House was built in 1900 according to records, but I suspect earlier.

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emcturkeyshirt t1_iy9r7uc wrote

Never switch a neutral.

However, with the newer electronic switches (dimmers, timers, remote switches…) a neutral will be required.

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iRamHer t1_iy9jv4m wrote

all switches do NOT require a neutral, not in any code I'm familiar with. your definition of properly is half baked and people reading should factor this when considering your comments.

while smart switches/ thermostats will require what acts as a neutral, switches in general do not. and depending on wiring, is completely unnecessary as to use the neutral you'd be doing major rewiring anyways. next you'll say we have to run a traveler or 2 to every box requiring 3 or 4 conductors when 2 suffice just in case, ignoring the need for breakers. some things do NOT need the ability for a smart switch due to safety, and thus neutral.

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Clcsed t1_iy9pp3z wrote

Switches do not require a neutral. Only light switch boxes require one to be available.

Keyword light. Not switch.

Edit: NEC 404.2C is what you're trying to quote... Other people alsoprovided the exact code in the comments here.

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iRamHer t1_iy9qb4y wrote

you missed the point and you're wrong. light switches complete a circuit when on, they find a neutral [or return] when on, when off they interupt that return, whether that's a correct or incorrect wiring method can vary.

an always on device requires a neutral OR alternative power. this means smart switches, smart thermostats, automated function devices.

if this were a multi phase wiring install that COULD differ.

please don't input incorrect or half right information. yes lights get the neutral passed to them, but convention has changed if you intend to automate. you're fully right if this were 1990 again.

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rivalarrival t1_iy9ps8h wrote

Can you cite this? The only reference I've found is to 404.2(C), which clearly specifies that it applies to switches with lighting loads. A garbage disposal is certainly not a "lighting load".

Further, there is specific exception in 404.2(C) for "receptacle" loads, which is what OP is trying to set up.

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who-really-cares t1_iy9qmcl wrote

Isn’t an exception to this when the switch box and wiring is accessible? So unless op is moving switch to wall it’s unnecessary?

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dominus_aranearum t1_iy9r0gb wrote

I'm wrong. Not a lighting load anyhow.

404.2(C)(7)

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who-really-cares t1_iy9r8qw wrote

Just found the code for anyone interested.

404.2(C) Switches Controlling Lighting Loads.

The grounded circuit conductor for the controlled lighting circuit shall be provided at the location where switches control lighting loads that are supplied by a grounded general-purpose branch circuit for other than the following:

(1) Where conductors enter the box enclosing the switch through a raceway, provided that the raceway is large enough for all contained conductors, including a grounded conductor

(2) Where the box enclosing the switch is accessible for the installation of an additional or replacement cable without removing finish materials

(3) Where snap switches with integral enclosures comply with 300.15(E)

(4) Where a switch does not serve a habitable room or bathroom

(5) Where multiple switch locations control the same lighting

load such that the entire floor area of the room or space is visible from the single or combined switch locations

(6) Where lighting in the area is controlled by automatic means

(7) Where a switch controls a receptacle load.

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TonyFugginMontana OP t1_iy8w1a7 wrote

Thanks for responding. Yeah, the plan would be to add plugs to both dishwasher and disposal. As far as the advantage? Beats me, but Home Depot seems to have expected to be able to simply plug in the dishwasher, and the fact they couldn't is one of the reasons I'm installing it myself now, lol. I also just want to be as close to code compliant as possible.

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>As to you wiring, you don't need to run the 12-3 wire to the switch, just wrap the ends of the white wire (that you have capped on both end) with black tape and use it.

I've seen tutorials showing that way, but then I've also seen some say that the new NEC updates for 2018(?) made it a requirement to use 12-3 and include a capped neutral... for whatever reason.

Anyway, if this is the case...

>The box inside the old dishwasher is a valid junction box.

I think that's what I need to hear. If the disposal line can just be spliced in at the junction box inside the dishwasher, the way it was before, without any safety or compliance issues, I would definitely prefer to just do that.

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roobinsteen t1_iy90mo2 wrote

Technically neutrals are required in every switchbox now, but if I were in your position I would just do it as described, creating a switch loop. The only reason the requirement for neutrals was codified was so that smart switches would be able to be installed everywhere (smart switches typically require neutrals). It's not for safety, that's the only reason. I don't imagine you or anyone will install a smart switch for you garbage disposal unit.

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TonyFugginMontana OP t1_iy947r0 wrote

Thank you. It certainly would be cheaper to reuse the existing 12-2 that is already in place going from the switch instead of buying new 12-3.

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rivalarrival t1_iy9vv75 wrote

Neutrals are not required in "every" switchbox now. They are only required for switches controlling lights. Even then, there are seven broad exceptions listed in the code.

Look up NEC 404.2(C).

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rivalarrival t1_iy9v7js wrote

>I've seen tutorials showing that way, but then I've also seen some say that the new NEC updates for 2018(?) made it a requirement to use 12-3 and include a capped neutral... for whatever reason.

This is inaccurate. The NEC requirement is 404.2(C), and applies only to switches controlling lights. Even if it did apply to more than lights, you are not obligated to upgrade your switch wiring to the new code.

And even if it applied to non-lighting and you were obligated to update it, there are seven listed exceptions, and three of them would probably apply: #2, you have access to the wiring without removing finishing materials; #4, the switch serves only a specific appliance rather than the entire room; #7, receptacle loads. (If the switch controls a receptacle rather than a light, it does not require a neutral.)

The purpose of the NEC requirement is that "smart switches" need a neutral return to provide power for their circuitry.

The way they had it set up is not ideal from a maintenance and repair perspective (you have to pull the dishwasher to repair the disposal), but is perfectly fine from a wiring perspective.

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dominus_aranearum t1_iy95r99 wrote

Current code does require a neutral at all switches.

Nothing wrong with using the j-box at the dishwasher as long as it has enough volume for all of the connectors. Each 12 gauge wire counts as 2.25 in^(3), all grounds count together as the largest, so another 2.25 in^(3) plus whatever gauge the dishwasher wires are (if less than 14 gauge, the conductors aren't counted), plus the cable clamp @ 2.25 in^(3).

12 gauge - 4 * 2.25Ground - 1 * 2.25Clamp - 1 * 2.25 (assuming both 12/2 in one clamp)

Total = 6 * 2.25 = 13.5 in^(3) volume required for the j-box.

I sincerely doubt the j-box on the dishwasher is that large. Changing to 12/3 for the switch would add an additional 2.25 in^(3).

Technically, both dishwasher and the disposer are now required to be GFCI. All outlets/hardwire within 6' of the edge of the sink. This even includes a range hood, fridge, range, etc.

There's no need for two separate outlets. There are two ways to do this. You can use a GFCI outlet or GFCI breaker.

You can use the two outlets you suggested, or use a GFCI/AFCI combination breaker and a single outlet.

First, break the brass bridge on the 'hot' side of the outlet only. Splice the 'hot' (black) and 'neutral' (white) prior to the outlet with one leg going to the top terminals, have the 12/3 head up to the switch. At the switch, cap the neutral, hook up the red to one side of the switch and the black to the other. Back down at the outlet, hook up your red wire to the 'hot' side of the bottom terminal. Double check that you've broken the brass bridge on the 'hot' side of the outlet.

Edit: Forgot that GFCIs don't have a bridge to break. Also, if updating to code, AFCI is required as well.

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TonyFugginMontana OP t1_iy99p2w wrote

Thank you, this is great info. Funny you should say that about the dishwasher j-box probably not being big enough. I (stupidly) didn't photograph the original situation but I seem to recall the box was not even closed all the way in the original setup, just partly fastened on one side and bulging open, lol.

With regard to the other solution, (I think) that is one of my earlier plans. I had even diagrammed that way: https://i.imgur.com/d1brqYl.png

But is it actually possible to separate the hot on a GFCI switch like that? It seemed like the GFCI switches like this one don't have the brass tab to break the connection. They just seem to have a designated "line" upper half and "load" lower half.

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dominus_aranearum t1_iy9c5g3 wrote

Brain fart. GFCI outlets don't have a bridge to break off so personally, I'd switch to a GFCI breaker and use a single outlet that has the bridge.

Technically, code requires them to be AFCI as well now, so I'd get a GFCI/AFCI combination breaker.

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TonyFugginMontana OP t1_iy9dfgo wrote

Thanks. I'm a total newb to all this and it's taken me days to get to this point, so I have no idea what replacing the breaker would entail. But I'll look into the possibility of doing that since using a standard outlet with half-hot switch wiring would be easier and cheaper.

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dominus_aranearum t1_iy9eq6e wrote

Going the breaker route probably won't be cheaper. Depends upon your electrical panel. GFCI/AFCI breakers can easily be $70.

If I were you, I'd just get the GFCI breaker and not worry about the AFCI. There's some debate as to whether they should be used or not.

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mr78rpm t1_iy9fnq4 wrote

Picky detail here: First, all of the parts for this wiring should be rated for 15 amps.

EDIT: I missed the fact that you're describing everything in terms of 12 gauge wire, which is to say, the wire gauge and all other details that are appropriate for 20 amp circuits. My experience has only been with 15 amp GFCIs, so that's what I wrote about. It doesn't matter which amperage rating you wire for, as long as it's done properly. One example of this "properly" is that if the feed Romex were 14 gauge, you would not be allowed to wire up the rest of it using 12 gauge. The way to think about this is: As you go further away from the panel, you either use the same wire gauge or smaller wire gauge (see my note somewhere else here... smaller gauge means larger wire gauge number).

Second, your final drawing shows the correct wiring but... look up a 20 amp outlet. Your drawing intends to show outlets rated 20 amps, where the hot plug holes are vertically oriented and the neutral plug holes are horizontally oriented. But it shows 15 amp sockets, where the hot and the neutral holes are both vertically oriented. This is minor in this discussion, but if someone decides to get this exact hardware and wire it up EXACTLY as shown, there can be difficulties. (Plus, this particular set of wiring parts should be 15 amp rated, not 20 amp.)

Don't be confused when you read "(if less than 14 gauge,...)."

I know how this should be wired but I don't know how to interpret the part in parentheses above. See, a wire that is smaller in diameter, which could be described as "less," has a HIGHER size number; a wire that is larger in diameter has a LOWER size number. For instance, 14 gauge wire is thicker than 16 gauge wire.

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dominus_aranearum t1_iy9kldp wrote

You say that all the parts here should be rated for 15A, but then go on to say the drawing intends to show outlets with 20A sockets. First, not my drawings. Second, why? 15A receptacles are rated for a 20A pass through and OP's drawing doesn't even have a pass through to another potential 20A outlet. By limiting the sockets to 15A, no 20A appliance can be run through a 15A switch, which would be the only potential concern here.

Why do you feel that the wiring should be rated at 15A vs. 20A? There's nothing wrong with wiring using 12 gauge for a 15A or 20A circuit. OP has a 20A circuit, which is wise when both a dishwasher and disposer share a circuit.

Anyone who wants to be confused by (if less than 14 gauge) shouldn't be doing their own wiring. Why would I list the volume requirements for 12 gauge, then go on to say less than 14 gauge isn't counted? People were confused by 1/4lb burgers vs. 1/3lb burgers as well, thinking that 1/4lb was bigger. These aren't the people who should be doing electrical work or ordering my food, even as a DIY.

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