wiring my house, where am I right and where am I wrong?

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Old 02-19-19, 11:55 PM
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wiring my house, where am I right and where am I wrong?

Ok, I will try to make it somewhat quick on each question. To make a long story short I am looking at buying this old house and fixing it up, money will be limited because I only got half the money in the separation so I am doing as much as I can myself. I have done plenty of wiring and making it "work" isn't really my problem it's making it "correct" and also "legal".

1.) I assume these days AFCI EVERYWHERE aside from appliances? is lighting exempt?

2.) I can use a 12/3 multi wire branch to the kitchen receptacles, AFCI in panel and GFCI in kitchen. But will the cost of a 2 pole AFCI breaker cancel out savings of 12/3 over 2 runs of 12/2...

3.) separate 12/2 circuit for disposal, fridge, OTR micro and DW? no circuit protection required, right?

4.) same as 2 but for bedrooms. do I have to try and balance loads or anything? like could I have one leg to a 1kw 120V wall heater and the other leg to receptacles?

5.) does the multi wire branch always have to service the same room? with 2 bedrooms side by side I could run 3 MWBCs and have 6 breakers - room A heater, room A wall receptacles, room A receptacles on opposite wall, room B other side of that wall, then the last 2 for the heater and receptacles on the other wall in room B.

6.) assuming MWBC can service separate rooms, 14/3 is way more than enough to handle 2 ceiling fans and 2 closet lights, right? anything out there say hall lighting/laundry closet lighting cant all be on that circuit? obviously not if its going to real close or go over that 15A load if everything was to be on at once.

7.) thinking about an on demand water heater, the 2 I am looking at either require 3 or 4 2 pole 40A breakers and 8 awg. are you allowed to install an appliance rated at 160A into a 200A panel? I know it's below rating but it doesn't leave much for the rest of your house. I know if I add the breakers up in my house now it well exceeds 200 but there is no single device using such a large % of the limit like there would be with this 36kw tankless.

pretty sure I got everything else, 10/3 to dryer and oven. staple within 8" of the box(in case I break the stupid clamp/tab) support every ~4 ft, run in between a couple fir strips on top of ceiling joist when perpendicular, staple to side for parallel. I think I got the distance from edge and the 40% hole size rule, etc...


poco says there was a fire and thats why the meter and feeders were pulled. I saw no evidence of fire on either side of the wall though. but if I have to replace the panel I now have to follow all the rules and get an inspection because I cant even leave the panel where it is, as it is over the dryer so there's no clear 36" in front of it...

sorry it was so long, thanks in advance. I am going to keep researching myself and if I find out difinitively one way or the other I may delete questions as I go but I need to get on this as soon as I close on this place as I would like to have power(heat) sooner than later.
 
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Old 02-20-19, 03:13 AM
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A lot will depend on which code cycle is enforced in your area as far as afci etc.

Lighting and appliances are not exempt from afci protection.

Yes dedicated circuits as listed for the kitchen. You will also need at least two 20 amp small appliance circuits to serve the counters.

The tankless WH will need its own service adding to your cost.The

Multi-wire coworkers as you think, but two pole afci breakers are rare. Much simpler to use xx-2 cables.

The 15 amp for lighting can handle much more than the two fans and a couple lights.
 
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Old 02-20-19, 05:12 AM
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3) Disposal and DW can share as long as both are standard residential size machines. Fridge doesn't have to be dedicated - it can share with one of the countertop receptacle circuits. OTR requires dedicated 20A.

Multiwire circuits really don't make sense in residential wiring anymore due to AFCI requirements. As long as you buy your 12-2 and 14-2 cable in the 250' packs or larger the price is negligible for separate runs.

On demand water heaters usually get _very_ expensive to install in a remodel situation. They can make sense when the service is designed from the start, but all the upgrades to an existing service likely cancel out possible energy savings. It often adds thousands $$ to the install cost.
 
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Old 02-20-19, 07:21 AM
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I agree with ibpooks. My advice is just don't have any MWBC's. GFCI can also be problematic on MWBC's, other than using a double pole GFCI breaker.
 
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Old 02-20-19, 10:03 AM
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alright, thanks everybody for all the answers. I planned on the 2 runs for the kitchen aside from the appliances. I was thinking of ditching the MWBC because of the afci complications but I just got the call back from the guy at the power company who pulled the feeders and it's actually that somebody built a big fire in the yard UNDER the wires... lol. so its within a year so I dont need the base inspected if I don't move the panel. He also made it sound like in this area they arent requiring or maybe just not enforcing the afci protection... says all work he sees around there are just standard breakers. I guess if I had to swap later I should stay with a GE so I can install their afci breakers. are they still the only ones that dont requre the neutral monitoring/pigtail to the bus bar? I just read about them last night.

anything I want to do will be easy for me as far as access though because the walls and ceiling will be open. it will almost be like new construction.

I am still debating the water heater because 3 runs of 8/2 will be about 125, 500 or so for the water heater, need 3 breakers and it ends up around 700 as long as I could use standard breakers. looks like I could do thhn for $60in but then its 60 plus the cost/complication/time of the conduit. 4500W 50gal tall is only 450 bucks, less electrical requirement and being electric(and the tall) there's really not much space saving aside from above/below where the tankless is but I wouldn't really utilize that space anyways. then a single breaker and single run.. the one nice thing would be later in life when I got 2 teenage girls I imagine the limitless hot water would be nice to have...

only larger gauge run that is very far from the panel will the oven. WH, dryer and furnace (if I go that route, probably wont based on cost vs just throwing in wall heaters in place of baseboard units), all will be within 12 feet of the panel so maybe 25' of wire to reach the furthest thing.

so if I can get up to using 12A continuous on a 15A breaker, I can calculate the bulb but the specs on the fans I looked up didn't list the motor... but I found somwhere saying less than 1A on high and maybe only .25A on low.

house is less than 1k sqft so I could probably put everything on the ceiling on 2 circuits (and panel will be somewhat centered) but is there some safety rule I dont know about where you cant have the entire end of the house go dark if a lighting circuit gets tripped?

I checked and 1k feet of 12/2 is 260 and 12/3 is 493 so it doesn't save money but its weird because it definitely saves on the 14/2 v 14/3... but it also seems like it would save time installing, less drilling, etc... so if I were allowed to use standard breakers would you still eliminate the MWBC?

last question, I looked in the settings but didnt see it is there a way to make this forum work like most where the OP is at the top and the replies work their way down. I end up here a lot on searches and it's weird to have to scroll to the bottom just to see the original question.
 
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Old 02-20-19, 10:28 AM
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The major expense with the demand water heater is upgrading the entire service to support it because it can require a 200A panel just for itself. That means you need to bring 400A to the property all the way from the power company pole. A refit 400A upgrade is usually well over $5,000. If you choose a smaller unit that will work with your existing service you will probably be pretty unhappy with the lukewarm water in the shower. It just doesn't work out for most people compared to a couple hundred bucks for a traditional tank WH. You can go with a 50 or 60 gal tank unit to get longer hot water run time with the kids.

My opinion is MWBC are unnecessarily complex for 99% of residential use. It's almost no difference in cost, adds labor to make up all the neutral splices and adds complexity in installation and maintenance for the next guy. There can also be some safety implications if they aren't installed perfectly. The only place it really makes sense for me is for running a couple circuits out to a garden shed without doing a full panel install.

You can put a lot of general purpose lighting on one 15A circuit. For a 1000sf house it's very common to have only one or two lighting circuits for all interior and exterior lights. Most of the time you also power your hardwired smoke detectors from one of the general lighting circuits.
 
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Old 02-20-19, 12:31 PM
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You can put a lot of general purpose lighting on one 15A circuit. For a 1000sf house it's very common to have only one or two lighting circuits for all interior and exterior lights.
That's all I do. All lighting on basically two dedicated 15A circuits.
 
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Old 02-20-19, 03:16 PM
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I know Square D has a .plug on neutral afci breaker. Cutler-Hammer may.also.
 
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Old 02-21-19, 05:05 PM
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I guess if I had to swap later I should stay with a GE so I can install their afci breakers. are they still the only ones that don't require the neutral monitoring/pigtail to the bus bar?
Do you currently have a GE 200 amp panel? If so, the breakers you buy should be GE. I believe it was Cutler-Hammer that pioneered the plug-on neutral loadcenters for the AFCI and GFCI plug-on neutral breakers without pigtails, but like has been mentioned, Square D has them too. I am not sure if GE has them or not. I haven't researched it, but would think Siemens has them too.

I looked in the settings but didnt see it is there a way to make this forum work like most where the OP is at the top and the replies work their way down.
Yes, there is a way for the oldest post from the OP to be at the top and all subsequent posts are below. I set mine up that way a long time ago and believe there is a setting somewhere for that. I'll see if I can find it.

Found it. Go to Edit Options under Forum Actions and scroll down to Thread Display Options and select Oldest Message First.
 
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Old 02-21-19, 10:28 PM
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I think its a cutler hammer but I cant remember. I meant that if I replace the panel but dont do the afci now I may as well get the ge panel so that shared neutrals wouldnt matter later with the ge afci breakers. maybe since ge wrote the page I wrote other companies have released breakers that also allow shared neutrals. BUT THEN I figured if I have the walls and the ceiling all open I can just wire it up so that neutrals aren;t shared since I plan on re-doing almost all of it anyways. I will just go with whatever breaker the panel is branded since I now found out I don't have to install a new panel.

also, I got the oldest first now in the thread view, didn't change anything else but now the "quote" buttons gone... I'll deal with that later.
 
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Old 02-21-19, 11:15 PM
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There should be no quote button. We moderators ask it be removed because people abused it quoting the whole post. You can still quote. Just use copy and paste to put a short relevant snippet inside quote taggs.
 
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Old 02-22-19, 02:56 PM
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I meant that if I replace the panel but dont do the afci now I may as well get the ge panel so that shared neutrals wouldnt matter later with the ge afci breakers.

That really doesn't make any sense. All manufacturers make single pole AFCI breakers and I believe they all also make 2 pole AFCI breakers.
 
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Old 03-01-19, 01:19 AM
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I thought from what I read, most manufacturers AFCI protection required the neutral wire for that circuit not be shared with any other circuit. I guess like in a bathroom if you have the lighting and outlets on different circuits but you have the switch and a receptacle in the same box you might have all neutrals tied together. I guess its probably not very common where you have multiple circuits in one box with the neutrals tied.

Anyways it sounded like GE had AFCI breakers that would function just fine in that situation claiming others wouldn't. Maybe that was old news I came across and it's no longer true or never was entirely...
 
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Old 03-01-19, 05:21 AM
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If you have two separate circuits in the same box, you never tie the neutrals together.

If you have a multiwire branch circuit (two hots with a shared neutral), then you must tie the neutrals together in every box AND use a two-pole breaker in the panel.

Most AFCI breakers are single-pole for single circuit use only with no neutral sharing. Some manufacturers make double-pole breakers that are compatible with multiwire (shared neutral) circuits, but they are much more expensive and are probably special order items at most retailers.
 
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Old 03-01-19, 02:37 PM
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Anyways it sounded like GE had AFCI breakers that would function just fine in that situation claiming others wouldn't. Maybe that was old news I came across and it's no longer true or never was entirely...

When the AFCI requirement first appeared in the 2002 NEC (I believe that's the year) only single pole AFCI breakers were available so new AFCI circuits had to have dedicated neutrals. Since that time 2 pole AFCI breakers are sometimes available. If you have existing multiwire branch circuits you always have the option of using 2 regular adjacent breakers with an approved handle tie and AFCI receptacles as the first device on each circuit.

I believe back in 2002 the requirement was to AFCI protect the entire circuit so you had to use the breaker, but I also believe the requirements have been modified.
 
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Old 03-04-19, 10:34 PM
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thanks for all the help everybody. I am in escrow and in 8 days or less I get to start hauling all my crap over there then start tearing into the place, first week or so will probably be spent fencing the place for the dog and kids, some yard clean-up, etc... before I actually get to to house. Picking up a 5th wheel tomorrow to stay in while i redo the house.
 
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