Rewiring Top story

So we live in a old house lath and plaster walls we are guting out the top story( it is a 2 story house).The entire house is wired on 3 breakers and the old box only has spaces for 4 breaks total so we going to put a new box in.We are also planing to run a sub panel to the top story to feed it.My question is when runing new romex wire what is the best way
1:run into the attic break off run the light/fan keep going and come down a wall and then bore holes in all the studs to run the average of 4 recps per room
2: skip the attic and just bore through studs to get to the destinations and run a line off the last recp to feed the light/fan
3: run it all through the attic and run down between the studs for the first recp then back up and over in the attic to the next set of studs to go between/or put a junction box in the attic and T off to run a line down between the studs

I am stumped on running it through the walls.I am don't know if you are allowed to bore through load bearing walls such as exterior walls.Then i read somewere about king studs and you are not supposed to bore through them?

The first image is to bring feed in through the attic and down the wall to the first recep then bore through the wall studs to feed the other 2 also to bore through to go from the 1 recep to the light switch then back up to the attic to feed the light
The second image is to bring the line in via the attic and go down between the studs to feed the recep and then come back up to the attic and go over to the next set of studs to run between for another recept
The 3rd image is using junction boxes to T off and go down between the studs of the walls to feed the recep also it could be done different instead of a junction box to feed light i could come off the recep by the light switch and feed it

 

You can branch from a junction box and run a cable to each receptacle or you can go from one to the other. Unless you are removing plaster you will not be running horizontally through the studs.

You can drill in a load bearing wall. King studs are used at opening like windows and doors and can be drilled also.

Wiring fished into finished walls does not need to be secured like if it were installed in open studs.

 

Another question not sure if i should make a new post or not its on the same subject kinda.I got a huge book on wiring to make sure i do everything to code and it says for install a new 200 amp main panel to use
"new,THW,THHW,THWN-2.RHW,RHW-2,XHHW(2/0 copper seen here)"

My question is i got THWN-2 and its just a 2 gauge wire not 2/0 it was rated for 120 amps my meter runs 2 leads am i thinking right here 200 amp meter 2 leads 100 amps per? is the 2 gauge wire i got going to work to go from meter base to my main panel 4 feet away? Or does 200 amp mean 200 amps per lead? i am a bit confused just need some clarifying

 

Wires are sized according to the overcurrent device, in your case 200 amps. You will need either 2/0 copper or 4/0 aluminum. Your #2 wire can not be used for 200 amps.

 

Ok well 2 gauge is what it has right now going into the current breaker box with 3 breakers lol can i put my new 2 gauge in for now so i can install new main breaker box and so some other stuff and put the 2/0 in monday when people are open i live in a place were everything is closed sundays

 

I can see adding a subpanel upstairs, saving all the individual circuit runs from the main panel to the upstairs, but a new 200 amp main panel seems like overkill. If you got by with 3 breakers before why would you need 40?

Also, if the feed in to your house from the transformer is not wired for 200 amp you are wasting money and may even be breaking the code by installing that panel.

I have all this on 100 amp service with no problems: Dryer, well, hot water, stove, cooktop, central air, and all the other normal 120v stuff in a typical home.

 

Another question just ran into a problem the house is old and there is only 14 in between the studs well the box is 14 3/8 lol can you cut a part of a stud out and put the box betwen it example thing line stud black area box

l
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This book aint very helpfull i am learning
It wont show the pic the way i made it but the stud would run down the center of the box
at top and bottom

 

Crispyb the top story is wired with like 3 different types or wire from the old knob and tube to what looks like a first gen non metalic it is spliced all over the place with no junction boxes and sometimes not wire nuted just twisted and taped lol.When we moved in when i was geting the power on the city elect built the 200 amp meter base and reran all the wired from the city side.I just went and looked at my meter at the lugs from the city side it says on the casing its 2 awg.Do i not need a 200 amp main panel then?Also the reason i wanted such a big box was to do it right and each room be on its on circut.The house was built in 1918 and has all kinds of splices and patches in the wiring.Come summer we going to have to run window AC's i dont want ot burn the house down lol.Also i promissed my GF i would put her a garbage disposal in as well as a new dishwahser we picked up.The house is also 5 bed 2 bathroom huge living room kitchen and dining room if i did not say earlier its about 1600 square feet also plan to get a CH&A sooner or later

Can you run 2 main panels? 1 for each story?

 

The right way to do it would be to cut a hole the the plaster 29.5" wide which should put you at the center of the studs on either side of the one you need to cut. Height of the hole should be 6.5" over the height of the box so you can frame in double 2x4 acrosstop and bottom of the opening leaving 1/2" wiggle room for the box. Verticle 2x4 at spacing to allow 1/2" on sides of box as well.

The new framing can be assembled on the floor and shoved in the hole in one piece and screwed or nailed into the existing studs. You'll have some plaster patching to do, but this is the only way to do it right.

 

If the city has 2 AWG from the pole it cannot be 200amp service or did you mean 2/O ?

Each room does not necessarily need to be on it's own breaker with the exception of the kitchen and bathroom. The bath should have it's own and the kitchen at least 2 so microwaves and toaster ovens are on separate circuits. Ground fault outlets are required in both kitchen and bath.

If you know which windows the a/c units are going in, you may want to have those outlets on their own breaker depending on the power needs of the a/c. Lighting and outlet circuits can serve more than 1 room especially if you go with 12/2 wire and 20A breakers.

They also make single breakers that will serve 2 circuits to conserve space if you go with a smaller panel.

You can only have 1 service entrance and main panel per building. Depending on how many circuits you will have on the second floor it may make it easier to have a sub panel up there so you only have to run 1 cable to the second floor. Read up on what must be done with ground and neutral in a sub panel.

Have you secured a permit to do this work and have an inspector sign off on it? If you don't, and you do have a fire, your insurance company will say sucks to be you.

My advice can only be taken as food for thought. I know little of what your needs are so I cannot tell you what to do with any certainty. I advise you to read that book you got and learn the relationship between your loads in amps, wire sizing and breakers. There is a lot riding on you getting this right and this is no project to cut corners on or improvise using only what you have.

Lot's of experts are here to help, so ask before doing if you are not sure.

 

Block, I'm not a pro, just someone that did what you are planning to do. I did it on my first house 20 years ago, it was similar size, two story, build in 1913, still had knob & tube. I did mine with a new 100amp / 20 slot panel. It was enough room & amps, however after doing the entire house I only had 1-2 slots available.

First, do it right & follow the codes. Get a permit & have it inspected, it adds to the peace of mind and helps when you end up selling the house. Its the right thing to do.

Why are you planning a sub- panel upstairs, especially if you do a 200 amp /40 slot main? I my opinion it is a lot easier to just run more circuits /romex than to have a sub panel upstairs. If you do the sub panel, now you have two places to check for problems rather than 1. Just find a clear drop from your main panel location to the attic and run the lines. I had three bedrooms & full bath on 2nd floor, used 4 circuits with bath on its own. I did not tear-out the walls, thus I ran my romex up & down within the wall cavities from box to box. Sometimes easier to go to the overhead light box (via the attic) & just branch off from there. Its cold outside now, so do the work now as summer is no time to be in the attic. I think if you price it all out, it will be cheaper to just run more romex back to the main than to do the sub panel. I also kept most of my wall plugs on interior walls, they are a lot easier to fish romex up & down.

For the window AC's, unless you are looking at big AC units, if you wire the whole house with 20amp circuits (general use) and put them on different wall plugs, you should be fine. Not sure where AFCI's come into play here given these are bedrooms, a pro will need to chime in on that.

If you find a clear drop from attic to basement, this is not a difficult job, just messy & time consuming. Buy your romex in larger spools, you will use a lot more than you think, buy boxes & wall outlets in contractor packs they are normally better & cheaper. I have not bought outlets for a few years now, but a $2 side clamp outlet beats the hell out of a $1 cheap backstab outlet. So it adds $20 bucks total, its better in many more ways. Finally I also ran cable for phone, cable TV, & internet at the same time. Figured I was up there, might as well do it all. By that time you already know the in's & out's of running cables, whats a few more.
Good luck & feel free to ask more questions when you need to. sorry for the long reply.

 

I would not go through all the effort to cut out a stud and install a header. I would shave the 1/4" off of the side of a stud.

Lighting circuits are so lightly loaded there is little reason to use a 20 amp circuit. Using the smaller wire also save on box space.

If a subpanel is installed you will need to leave a refrigerator sized work area clear around the panel. It cannot be in a closet.

 

Mike I live in a little dump we have no city inspector the city does not even do there own elect work like turning on new service they outsource it and pay another company lol.I have the new box in i took the 200 amp box back as it was just way to big.I got a Siemens 100 amp main breaker 20 spaces.It measured in at 24in tall 4in deep 14in wide it was still 1/4 to big so instead of fighting with the stud tring to shave 1/4in off i cut out 26in of it and sister studed it 2 feet past the top and bottom cuts and it fits great.The reason for the subpanel is i though it might be easier to do the wiring and save a bit since just running the wire up the wall is about 30 feet.I also wanted to run each room on its own breaker i know people say you can run multi rooms per breaker and such but it does not seem like the right way to me.I was planing on running each room on its own breaker and having the lighting and recp in each room on same circuit.The way i think of it is if i ever did have a issue it would be easy to find 1 room 1 circuit instead of omg all the lights are out upstairs now i get to run around the whole attic

If i ran a sub panel i could run like a 75 amp box upstairs as it is all bedrooms and 1 bathroom.so instead or uning multi wires accross the attic and down the outside wall to the main i could run 1 like 6/3 to the sub.

As sad as i am about what i had to do with the main i wont openly admit to doing wrong but were the main is was a tight spot its were the old one was in the kitchen its got cabinets to the left of it a window to the right of it.If i did not put the new box were the old one was the next option would have been to have to put it about 15 feet away on a interior wall.NEC is what a inspector interprets to be.Ya the main cant be in a closet but when i helped my dad do his gut of his house and remodel they let him.....I have 33in between the cabinet and the window on the wall.Maybe in the future i will move it but for now its just got to work so i can start upstairs and when i get around to working in the bottom story it can be moved

On another note sorry for my spelling and a long post but i was wondering i did what ya said mike i bought the wire in a big roll 250 feet to start off with but i got 12-2 and really dont want to use 20 amp recp.The book says the recp has to match to circuit so what can i do?
1:use 15 amp breaker with 12-2 wire and 15 amp recp?
2:was told i could run a 20 amp breaker with 12-2 and 15 amp recp since the 15 amp recp wont accept a 20 amp plug?
3: use 14-2 wire 15 amp breaker 15 amp recp?
4:20 amp breaker 12-2 wire 20 amp recp

Also mike according to NEC a window AC has to have its own circuit.Anything considered a perm appliance just got done reading it in the book.It also says in a kitchen each major appliance is supposed to have its own circuit if i follow the NEC i could use 8 circuits in the kitchen alone.

 

The open-air splices for knob-and-tube wiring are twisted, soldered and taped.

You may want a 200A service to have enough to include your heat and air. Do a residential load calculation to see.

When I rewired our 1908 house, I installed the main 200A panel in the basement, straight through the wall from the meter base. That big panel had a handful of breakers for lights and receptacles in the basement, the furnace controls and blower, the condensing unit, and two subpanels, one for each floor. Those subpanels fit nicely in the narrow space between the rough-cut 2 X 4 studs. The important thing is to make sure you have enough spaces for the loads on each floor. Kitchens are circuit hogs.

Not sure why you consider having each room on its own circuit to be either proper or desirable. I run 15A #14 AWG circuits for as many light outlets as they will hold. Sometimes a whole floor. I run 20A #12 AWG circuits for the receptacles, and I try to get more than one circuit in each room. That way there are two or more sources of plug-in power plus a separate circuit for the lights in each room. Harder to get stuck in the dark without power that way, and a lot handier when working on something.

 

Block, again I did mine over 20 years ago, different NEC rules. I also had a City inspector that said do this, this & this, then I will sign-off. He actually was a big help in suggesting best ways to re-wire the entire house, & acceptable workarounds.
Do the load caculation as suggested above, map out how you would do the entire house. Think of the entire house & circuits covering more than 1 room at a time. Maybe the 100 amp will be OK for you, the problem may be when you go for central air & heating. I had neither since it was in Michigan & used boiler heat. If you do the sub panel upstairs it will add circuit slots but not AMP capacity. The central AC & Heat will need amp capacity. I have no big deal with how / where you installed the panel, that's where the prior panel was.
15 vs 20 amp circuits. OK to do either, but try to be consistent. Be sure to use the proper guage wire with the proper breaker size. 14 ga wire is alot easier to work with & is most certaintly fine for lighting & general use outlets. A 20 amp (12 ga wire) allows you to put more on it, thus maybe you can get by with 1 or 2 less circuits from a whole house perspective. Remember not every outlet & every light will be used at its maximum level at the same time. Your comments about which way to do the outlets - either # 2 or #3 works fine & is legal. The problem with mixing bedroom outlets with others is the AFCI. Again I am not up on current NEC, the pros need to give some guideance there.

 

I talked to the old city electrician he said 100 amp is fine for now since we run mostly on NG we have NG dryer/water heater/furnace.He said i could do a subpanel upstairs and should i ever need to upgrade to 200 amp service i could have a new main breaker put outside under the meter base and convert my current 100 amp main into a sub panel and have a bottom story sub panel and a top story sub panel.The reason i wanted to feed each room its own circuit is when i helped my dad run his the city inspector made us put each room on its own.He also made us feed the livingroom on 2 circuits and each GFCI above the countertop he made us put on its own circuit

PS: new box is working great to got it installed and no problems also got 2 new circuits run for the dishwasher i got for my GF and garbage disposal NEC says each has to be on its own independant circuit

 

Do the load calculation, including everything you might add in the future. A 200A panel costs only pennies more than a 100A panel and electricity costs what you use, regardless of the service size up to 200 amps in most jurisdictions.

In our 1908 house we used NG for the furnace, water heater, clothes dryer and cookstove. The decision to drop with 200A was based on the load for the central air we added. The conditioned space in that house was about double what you have and there were a lot of cubic feet to cool. It needed a big condensing unit.

I forgot to say earlier that I install 15A receptacles on all 20A general service circuits. I also pigtail each receptacle rather than relying on the bridges on the receptacles to continue the circuit without failing.

I can't remember supplying any room with only one receptacle circuit in the last 30 years, and the lighting is on a separate circuit from the receptacles. Besides helping to insure power when there's a problem on one circuit, that makes it easier to control harmonic interference.

 

To add more detail to what Nashkat1 said about the 15A receptacles, they are allowed to be installed on 20 amp circuits. They will pass 20 amps through, but you can't plug a 20 amp appliance into them.

I think installing 200 amps is the way to go. I think 100 amps just isn't going to be enough for future needs. Like Nashkat1 said, it doesn't cost much more to have the panel. Historically, demand for electricity in your house has grown. I'm sure after you are done with this project, you are not going to want to install a new service panel down the road and rewire it.