'splain please. It was a 12/3 going to the right for the over-the-sink light switch & receptacle then down to the D/W. You got me scratching my head on that one! I don't have a clue why there is a third conductor running to the DW. It might be worth looking at the termination of that wire. My hunch is that one of them is unused, but who knows? "I think the Two-Pole GFCI 20A breaker is a great idea. The breaker box is in a back bedroom so if it trips, no biggie in getting to it. Also, I read this while Googling Two-Pole GFCI 20A breakers: 'GFI devices cannot operate on circuits with shared neutrals.' True? False? Isn't that what I have (circuits with shared neutrals)? Just trying to cover all bases." That's a great question. As of maybe five years ago, I think the correct answer would have been "true". (How old was the source of that information?) But now, there are (at least) two types of two-pole GFCI breakers. The simple 240V two-pole versions will not work, because they only measure current imbalance between the two opposite-pole hots. These may have a white pigtail to the neutral bar, but that's only to power the internal circuitry of the breaker (essentially 120V). The second type--designed for 120/240V circuits--will work on an MWBC with shared neutral. These have a lug on them to attach the shared neutral as well as a pigtail to the neutral bar. Basically, they compare the output of the two hots and, if they're out of balance, they measure the current on the neutral to account for the residual difference. The bottom line is that it's important to make sure that the breaker monitors the neutral current and is suitable for use on the MWBC. (Also, it is possible that not all manufacturers offer a compatible breaker, especially if your main panel requires an old, discontinued or scarce breaker type.) BTW, your question made me rethink my estimate of a $30 cost differential. Those 120/240V GFCIs were quite expensive when they first came out a couple of years ago and I'm not sure how much they've come down in price. I may be too optimistic on that guess about price, so you might want to look at price/availability before you decide which way to go. (Also, if you can't find one at a big box store and have to go to an electrical supply house, they have a way of gouging a one-time walk-in DIYer with a ridiculously high "list price"!) *** Broaching a related issue here. If you go the route of changing the hardwiring to "plug in", I hope you're aware that you'll need to retrofit the appliances with proper cords and plugs. You shouldn't just put a new plug on the romex tails! "Retrofitting" is probably more easily done with the disposal, since they frequently come with a plug-in option. But dishwashers? Not so much.

What should I look for to find info on 'heat pump mini split'? Any particular brands of other considerations? My walls are 74" high. I will be hanging ceiling joists on top of the cap rails at 16" oc and covering top with plywood or osb for loft storage. That will probably only be about 4' deep on each side of the building leaving me with 8' of overhead to play with. I don't really want to wack my head on lights, so I can embed them between ceiling joists or recess them or whatever. I don't want to have any question about seeing anything, or safety. So I will not skimp on them. However, I don't want to go overboard cost-wise. So I would like good bang-for-the-buck... Where possible, I will do my best to comply with NEC2011 above and beyond my inspector's requirements. I don't see anything they are requiring that is above what is in NEC so far. Now that once again the idea of home runs to each outlet has been raised, what does that suggest about the size of panel I need? In theory, I could put a box (4 gang?) every 16" with a single 250 outlet above it or perhaps 6 gang and have them all together. So I could have 4 120's plus 1 240 every 16". But wait there's more! Initially I wanted to have knee level outlets as well as counter top level outlets, and what the hell, how about a ceiling one as well. That would come to 12 120 outlets and 3 240 outlets every 16 inches (with the exception of the wall with the double door and where the single door is (and the windows, would not really have a counter top level position. That would add up to a severely ridiculous number of outlets, and if they were all home runs, I thing would require a panel the whole size of one of the walls. That said, 'you can never have too many' is probably incorrect, though idealistically I can agree. Realistically, I need to come up with a reasonable number somewhat less than that. :) It seems reasonable that I can get a panel that has 22 slots. I assume that gives me up to 44 circuits on 120 tandems, or up to 11 240 circuits, or more likely some combination thereof. because I am a cheap b*d, and I had to yank 2 perfectly fine 15 amp cutler hammer breakers to put in a tandem so that I could even fit a 100 amp breaker in the house panel, I will be purchasing a cutler hammer panel, and using those 2 15 amp breakers. I assume they would be fine to run lights and perhaps a smoke/fire alarm. I think I would have to be running a bunch of 500 watt halogen work lights to toss the breakers on that, and I don't really intend on running halogens in there anyway. I will wire the runs with 12/2 or 12/3 anyway, so when those breakers do give up the ghost I will not feel bad replacing them with 20's... just because. That does away with 2 slots leaving me with 20. If I put in 6 240 circuits that would leave me 8 slots and I could tandem them to 16 120 circuits. Obviously, I could have multiple outlets still on such a layout, but I obviously could not use them all simultaneously without going over the 100 amps. But, let's see where I can go with this. If I go to 4 gang plus 1 per placement that would give me 4 circuits per box duplicated above and below and on the ceiling and same for the opposite side of the room. This could be repeated 4 times down the length of the building giving me a plug point every 32" that will give me a choice of 4 different circuits or a 240, with the understanding that so long as nothing else is plugged along that 'longitude' it will not share the same circuit. This also leaves me with 2 additional placements of 240's that perhaps could be reserved for special purpose things, such as a welder, or climate control unit or something of that ilk. That is not counting the GFCI, but that is a detail. So we are talking about 48 split duplex 20 amp outlets, and at least 12 20 amp 240 outlets and perhaps a 30 or 50 for good measure. That is the closest I can get to overkill and still feel like I am describing a somewhat sane layout. Still, it seems almost double what I will more likely do. I assume there is a limit to the number of wires that I can fit through a hole in a 2x4, and again, if I am using 4 gang boxes to put 4 separate circuits in each one, I am not sure I have the confidence that I can fit all the pigtails and wire nuts inside the boxes and still have room for the outlets themselves. Is there a tool for planing the layouts/runs online or on the computer other than just pencil and paper? Am I just getting silly, or would someone actually wire a shop like this?

I had a similar situation, and eventually just hired an electrician to do the job. I was switching from 100A to 200A service (my old service was to a fuse box with 100 A cartridge fuses and 8 screw fuses, mostly 15A but one was higher (30A, I think) for the electric dryer. I installed the 200A breaker box next to the old one and transferred all the wires to the new one. I then ran a 4 GA line from the old fuse box to the new one. I then had the electrician replace the meter pan and remover the wiring to the old box and run a line to the new one. I had contacted a local inspector who said "yes, you can do it yourself. You would call the POCO to disconnect your old service. You could then replace the meter pan. Then you would call me to inspect your work. I would probably come in a couple of weeks. Then call the POCO to reconnect the new meter/pan. That would probably take another couple of weeks." Hiring a licensed electrician cost only $800, so that's what I did. Interestingly, he did not think the line from the pole to the house had to be replaced!

"So, in the current setup or as I have diagramed above still maintaining a single circuit, is this system inadequately grounded?" As a single circuit, it is presumably grounded just fine, as long as there is a proper grounding electrode system back at the main house panel. "I had assumed the circuit being fed consisted of a live, neutral and ground (the twisted bare). " As it is set up at the current time, that is correct, but it wasn't originally wired that way when the actual wire was installed. They didn't DO ground wires back then, and a "bare wire" does not infer that it is a ground wire, just not "ungrounded" (HOT). That is a cable with a concentric neutral. I doubt that either of the insulated wires are "identified" as a neutral (white insulation). "200.2 (A) Insulation. The grounded conductor (neutral), WHERE INSULATED, shall have insulation that is (1) suitable, other than color, for any ungrounded conductor of the same circuit on....." "200 .6 Means of Identifying Grounded Conductors. (A) Sizes 6 AWG or Smaller. An INSULATED grounded conductor (neutral) of 6 AWG or smaller shall be identified by a continuous white or gray outer finish or by three continuous white stripes on other than green insulation along its entire length. Wires that have their outer covering finished to show a white or gray color but have colored tracer...." "Regarding the disconnect... " This depends on the final decision of how you wire it. As it is wired right now, you would only need a standard toggle switch (just like the ones that turn on the lights). If you make it 2 circuits, you may only need 2 standard toggle switches, (just like I cut and pasted them out of your original drawing). You really only need something that looks more industrial if you need to install over current devices. Do you know what the actual wire gauge of the cable going from the house to the garage is? Back then, a common thing to do was to put a dryer receptacle in the garage. (Funny enough, I just noticed that there is a documentary on the outlawing of clothes lines in many parts of the country when the dryer became popular.) In other words, that may have originally been a 30 amp wire and a gas line to make provisions for either type of clothes dryer.