Doing ANY wiring is dangerous if you don’t know what you are doing! And don’t check it out before doing it. (Which is what Joey P is doing here,)
But I don’t see how it is any more dangerous than other wiring. It still has just 240 & 120 volts, like other wiring. If you pay attention to that, and check that the wires are at 0 volts before working on them, no problems.
I believe that the worry is that if the devices are on different breakers, a Reader’s Digest or Youtube handyman might turn off one and not the other, and be unaware that one wire is hot.
It’s a little more complex than that. The problem with multiwire branch circuits isn’t that if you turn off one breaker the other conductor is hot, it’s the the neutral in the circuit you’re working on is/can be hot. Also, If I run two hot wires and one neutral and the two hots are on the same phase there’s the potential that the neutral (which doesn’t contain a breaker or fuse) can see twice the amp load than it is rated for.
Both of these problems are rectified by using a double breaker with the handles tied together (like a 220 SPDT breaker) to make sure that both circuits are off at the same time and that both hots are on opposite phases.
I did fine one shared neutral that wasn’t properly wired (for today’s code, I think it was okay for the code in force in 97) in my panel which sort of surprised me. All the other wiring (that was done when the house was built), appears to be very well done, so I’m not sure why they did this one this way. I can only guess that someone got lazy or ran out of time or wire or got tired or something. I may fix it when if end up rewiring anything. However, at the moment, I’m leaning towards not, or at least not running a new wire. The more I think about it, the more it’s going to be a huge job. It’s either going to be drilling through 35 floor joists or fishing it up into and back down from the attic and then stapling it to 30 rafters and dealing with the blown in insulation all while at the very narrowest part of the attic.
OTOH, just taking the 15a wire that drops down from the attic, to the switch and to the disposal, I should be able to splice into that in the switch box and drop it down to the dishwasher. Much easier.
I’m fairly certain a shared neutral doesn’t work with a GFCI breaker. The hot and neutral flow would be different if something from the other circuit is on. I haven’t researched the paired breakers though.
In the OP, the quote of the local building regs,
the first part of 4 seems to be the opposite of 5. If I put a dedicated appliance receptacle say for my fridge behind the fridge, is it still accessible?
I’ve never seen a double GFCI or AFCI breaker (not that I’ve looked all that hard) so there’s that.
A fridge, from what I’ve read (but glanced over since it’s not what I’m looking for) doesn’t require a GFCI if the outlet is behind the fridge, but does if it’s next to it. This is becoming more common (or more ‘in code’) as requiring are going from ‘within 6 feet of a sink’ to ‘anywhere in the kitchen’. But since ‘behind the fridge’ isn’t accessible’, there seems to be an exception for that. My theory is that they’re worried that if one snaps, it could be hours before it’s noticed, but more importnantly, days before it gets reset if the homeowner isn’t strong enough to move the fridge. That could create food safety issues.
Now, for dishwashers, an outlet can’t be in the dishwasher space, that’s considered buried, period. It must be in the cabinet next to the dishwasher. What’s interesting is that even though that’s clearly within 6 feet of water, recent NEC regs didnd’t require a GFCI outlets. But I think that’s because, up until recently, motors tended to trip GFCIs.
A GFCI, at least to me, does seem like a good idea, that’s why I figured I would just get a GFCI breaker and be done with it. It’s not technically ‘readily accessible’ by the strict standards, at least I don’t think so, but I also thought I saw some wording that stated that the ‘circuit’ needs to be GFCI protected as opposed to the receptacle (receptacle includes the point where the appliance is hardwired into the house wiring, so you can’t say ‘Ha!, I hard wired it, there’s no outlet, gotcha’).
IOW, dishwashers and fridges have special wording in the NEC, mostly because they’re not easily moveable. What they don’t want, so far as I can tell, is for you to wire all the outlets on your counter as GFCI daisy chained from out GFCI outlet that’s in a cabinet, behind an appliance or in a place that ‘requires a tool’ to gain access to’. Basically, if it flips, the homeowner needs to be able to reset it without any trouble. Also, I believe, technically, you’re supposed to test them once a month. Not that anyone is going to do that, but, out of sight, out of mind, however, there are some that test themselves on a regular basis, but I don’t know how those work into the code.
In the end, you can argue all day, but it comes down to what your local inspector likes and what they’ll sign off on (if you’re pulling a permit, which I’m not).
Hit submit too soon, let me finish typing…
TLDR, I think I’m just going to run BX across my basement joists. Quicker than anything else I can think of and still up to code.
I think I may have figured this out…
First off, I did spent a few minutes in my attic…didn’t see a one friggin wire, other then a few that I assume were for ceiling fixtures. That tells me that I’m either wrong about all the wires going into the attic and that they actually run around in the first floor stud walls (it’s a one story house BTW) OR, they were run so well, so tight to the rafters and so close to the perimeter (possibly even between the top plate and the outside sheathing) that I just can’t see them under all the insulation. Either way, getting a wire up there, back down where I need it and not just running it across the attic like an extension cord would be a royal PITA.
So, I went back to one of my first ideas, running regular conduit and pulling wires. However, there’s a few tight areas, so I looked into BX. The question is, can BX be strung along the bottom (perpendicular) of joists. According to the 2011 NEC, yes, it can:
(well, maybe not specifically “BX” but we’ll get to that).
Okay,
2011 NEC Regarding “Armored Cable”
The 2014 doesn’t appear to change this.
300.11(A) just gives other places where wires can be run in addition to to what this line says.
MC type “BX” (yes, I know it’s a brand name of one or the other), isn’t allowed, I assume because it doesn’t contain it’s own ground, or so I’m reading, but I see both AC and MC with grounds…now that I think about it, it may have to do with the ground being insulated or not. You also can’t do this with Romex (NM), but that’s because it’s too easy for it to be damaged by accident. I did see something or another about only allowing it to be 6 feet bit I think that was for Metal Clad cable and only if the metal clad itself was being used as the ground. That wouldn’t be the case here.
Anyways, if I can just run AC cable, I’m golden. That’ll be way easier.
Now, assuming that’s out of the way, the next question becomes, do I run a 12/2 cable from the breaker over to the dishwasher and leave the disposal alone. That would be the easiest thing to do. There would be no messing with the switch that’s up above the counter. OTOH, I can get a 12/3 cable and just redo all of this while I’m at it, but that reresents a lot more work, as well as a wire original wire that I’ll have to abandon in the wall.
One thing I still see argued over is what’s considered readily accessible when it comes to a GFCI protected dishwasher. Or, more specifically, can you just use a (AFCI/)GFCI breaker. I see the NEC allows them in very specific circumstances, but doesn’t seem to disallow them for other things.
As I’ve said eariler, from what I’ve read around the internet, GFCI outlets burried in the your sink cabinet aren’t usually readily accessible because of all the clutter down there. Now, not being a hoarder, my electrical panel is (no pun intended) easily accessible, you can just walk right up to it and see what’s going on. No tools, no ladder, nothing to move, it’s just right there. OTOH, I can see running into ‘within sight’ or within X feet or ‘being able to quickly reset it’ issues.
If I use 12/2, my gut says to just drop in a GFCI breaker and be done with it. FTR, spending exactly 30 seconds looking, I do see SPDT GFCI breakers. Expensive, but they do exist. However, I really didn’t look at them close enough to see if they’re only for 240 or if they can be used for 120 multiwire as well.
For those of you still playing along, at the moment, I’ve been trying to figure out exactly what the difference is between AC and MC conduit. The NEC specifically mentions that AC can be run perpendicular to joists. A lot of other sites seem to imply that the NEC just doesn’t disallow doing the same with MC.
Fun stuff.
FYI - Electricians use a LONG 5 or 6 ft. drill bit called a D’Versibit. These drill bits have a hole in the end which you can use to pull a wire back through the hole. These are sold at home improvement stores in the electrical department or at an electrician’s supply.
Here is a video of how to use this bit to run wires in an attic.
I have a some of them. They’re meant for getting the wire up from the basement or down from the attic to the box location. I’m not sure what that has to do with this thread.
This thread has never been about how to get a wire from dishwasher to the attic or basement. It’s about getting it from dishwasher across 35ish joists and to the panel. Moreso, it’s about avoiding drilling 35 joists.
[quote]
Here is a video of how to use this bit to run wires in an attic.
[/quote]That video is how to run cable to an attic, not in an attic. As I said, I have some of those long drill bits, I’ve used them to add boxes or outlets, they can make life easier (if you’re careful and don’t just punch through the drywall in the other room).
Anyways, back to what I was saying before. It looks like if I used the correct type of wiring (AC) I can just string it across the joists, so long as it’s stapled to each and every one and I’m good.
I’m not looking forward to working over my head like that, and I’ll still have some tight corners, but this should make my life a lot easier.
Also, I’m still leaning towards not messing with the garbage disposal. It works, it’s wired properly (except possibly needing a GFCI) and messing with it will involve fishing up into the drywall.
This will be much easier, just run a 12/2 armored cable from the panel either to a (metal) box in the cabinet next to the dishwasher or right to the dishwasher junction box itself, with enough slack to the dishwasher to slide out.
Haven’t decided on that part yet.
Also, have to give some thought to the whole GFCI situation. If? Where? etc.
Okay, another (non) update. I’ve given this way too much thought over the last few days and spent a lot of time pouring over the NEC and my local codes.
I still maintain that AC (BX, not MC) can be run the way I want it to, the NEC supports this, but, oddly I can hardly find any references to anyone (on the internet) doing this. It just doesn’t seem to be done, or at least not often.
First a few quick pictures:
The bulk of the run, the hard part:
Not sure if you can make it out, but just to the left of the water heater and big white PVC drain, you can see a copper water pipe (you can see it between the PVC and the furnace duct). That’s about 35 or so joists away.
Also, I can’t (easily) go around the left side because there’s a concrete wall where you see those two grey platform bed things leaning (behind them) and the ducts along the ceiling run right up against the joists. That means something going over there would have to go up and over the duct work, then come back down. I’m sure skilled electrician could just glance at it, walk outside, bend a pipe a few times and it would just fit…but that’s not me an I’d rather not make 10 attempts at bending pipe (used to be good at it, not so much anymore) and factory elbows attract attention, at least IMHO.
I mentioned earlier that AC type cable could be run along the bottom of joists with no further protection (this is the original ‘bx’). Turns out that stuff is really hard to find. Everything in the stores is MC or MC-Lite and you have to treat that like NM/Romex, which means either through the joists, on running boards or running boards on either side of it. None of which I have any interest in.
Today, I took a closer look at a small gap in the mechanical area, I wondered just how wide it was…
For reference, when looking at the first picture, this is looking back to between the PVC drain and the ductwork. Looked like it might be just barely wide enough. I happened to have some 3/4 PVC laying around and tried to get it in there. It might have worked, but some of the clamps on the water pipe are broken and have shifted. However, I measured it and I have a half inch, at least near up against the ceiling. Looking around my basement, I found some old half inch EMT. Turns out, with some persuasion, it does fit into that small gap. Barely, it really has to be pushed/slid in, but it does fit. That means I have a straight run all the way from one end of the house to the other. Aces.
So, at the moment (subject to change, of course). My plan is to run 1/2 inch EMT from one end of the house to the other. Run romex (most likely, maybe MC-Lite), to the breaker box. Then at the other end, I’ll either bend the tubing, or more likely, switch over to MC-Lite, which I’ll then be able to run in a single joist bay the rest of the way. From there, it’s just a matter of getting juice up to the cabinet adjacent to the dishwasher. My thinking at the moment is to use MC, since it’ll be easy to run and I can bring the cable in wherever I want it…I’m thinking of having a GFCI outlet near the front of the cabinet so it’s ‘easily accessible’.
It does appear that if the dishwasher is plugged in, you don’t need a switch.
It also appears that you can’t run MC cable ‘exposed’ in this situation. However, I should be able to run if through a PVC sleeve, so I’ll do some reading up on that, I’ve never sleeved anything before. It might end up being easier to bite the bullet, make the bends and run conduit the entire way.
But, at least a big part of this is out of the way, now that I found out I can, in fact, get metal conduit (easily, kind of) from one end to the other. Also of note, the conduit, due to the hangers on the water pipe, won’t come in contact with the copper pipe. It will, as I have it planned in my head, run along the (return air) duct work. All the NEC says about that is that you should avoid having conduit touching a dissimilar metal ‘when practical’, but doesn’t expressly forbid it. There’s also two joist hangers it’ll touch, but but finding the right conduit hangers or small piece of neoprene should take care of that.