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fdmillion 10-24-2012 01:09 PM

Major interior remodel - a few questions

I'm doing a major remodeling on the interior of my new home (my parents lived in it and they're giving it to me). The house was built in 1911, and has all original K&T except for the addition and the finished basement, which were done in the 90s and 80s respectively.

Turns out the house actually has NO insulation AT ALL, it just has double-thick plaster-and-lath, so I'm pulling all of that out, exposing the framing, ripping out all the old K&T and wiring in a whole new electrical system.

The old system is a HUGE mess, a disaster waiting to happen. There's SIX subpanels connected to the "main range and four" panel, some stealing power off the range circuit side, nothing is labeled AT ALL, and circuits do not make any sense. (I took out all but one fuse, and the furnace blower worked, but so did the lights in one room on the second floor; another left the basement outlets running but one outlet in the kitchen also had power...)

Not to mention as I've been opening the walls I'm finding frayed K&T, splices with hanging electrical tape, completely exposed splices, and mass overcrowding in switch boxes. Also, some really BAD wiring mistakes - tying Romex to K&T without a junction box and with electrical tape that's worn off by now. Even found a neutral bound to a ground. Someone who lived here before me or my family was a horrible DIY'er.

I have some experience, I've done single rooms and many repairs, but this is the first time I've done a huge major project like this. I do feel confident in my skills and just have a few questions.

Here's my plan:
  • 15 amp circuits for all 3 bedrooms
  • 2 15 amp circuits for the living room
  • a 15 amp circuit for the dining room
  • a 15 amp circuit for the family room
  • 2 15 amp circuits for basement outlets and lighting (one would run the washing machine and water softener)
  • dual 20 amp circuits for the kitchen
  • 20 amp circuit in each bathroom (2)
  • 20 amp 220V for central air (that's what it has right now)
  • 30 amp 220V for electric dryer (same, has that right now)
  • 15 amp for furnace blower
  • 30 amp 220 feed to subpanel for detached garage (this will probably have to be redone, right now looks like just a run of somehow-armored 12/3 suspended overhead outside between house and garage)

So at 110 we have 10 15A circuits and 4 20A circuits; at 220 we have 80A of total circuits

Here's my questions:

1. I'm assuming that I don't need to worry that the total ampacity served to my house may be lower than the total ampacity of all circuits combined? (It'd be a rare day that every circuit is being used to max capacity! lol!) Going to see if the power company would be able to bring me up to 200A, but they might only be able to do 150A in my neighborhood. (Looks like I have 100A now.)

2. I'm going to be running a LOT of romex for this, so do I need to be aware of anything when it comes to crowding? I.e. there is going to be a huge bundle of wires all leading to my new loadcenter. Can I bundle them together? What's the limits there?

3. To go over doorways and across rooms I'm basically going up the stud, through (when perpendicular) or stapled along (when parallel) a ceiling joist, then back down the other side. Good idea? This means some doubling or tripling of wires stapled to studs and joists. I'm running a max of about 3 cables through a single 3/4" hole bored through a joist, is this OK?

4. I'm using brand new fiberglass insulation on the exterior walls. Safety concerns for wiring? The wiring in the one room we already did is running horizontally along the wall, through holes bored in the studs, but it sits on and is in physical contact with the insulation.

5. I'm also running new Cat5 cable along with the electrical. This will also be being dropped to the basement, to a central patch panel. I've read that the best way to do this is to just staple the cable along joists and through holes same as electrical but keep it at least one stud or joist away from electrical to help with interference. IS this going to be OK?

6. I have plastic wall boxes with punch-out knockouts for wire. (These are not the blue ones with the plastic clamps that hold wire; you punch out a really thin section of plastic with a flathead and it leaves a small, irregular hole.) As I understand it, as long as I staple the cable to a joist or framing member no more than 6 inches away from the box, I don't have to worry about clamping it to the box itself... is that correct? How about for boxes with 2 or 3 wires going into them? (outlets mid-run, 3-way light switches, tapping power in a box to feed a light/switch, etc.)

7. Since the wiring in the basement and the addition is all new Romex that would have been up to code at the time it was installed, can I just throw a junction box in the wall and make a new run of Romex down to the loadcenter from it? Right now it's tied into the K&T somewhere, not sure yet because we haven't taken out those walls yet.

Like I said I've done wiring in single rooms from scratch but this is the first time I've done a huge project like this, so I just wanted to check on code requirements and the like and make sure what I'm doing will end up being approved. I do have a basic code guide but it's not very comprehensive on matters like these. :wink:

I may have more questions as the project proceeds, but that's what I'm immediately curious about right now.



AandPDan 10-24-2012 01:52 PM

Are you pulling a permit for this? What Code cycle are you on? I'm showing 2011. You'll very likely need AFCI breakers for the required locations.

It doesn't matter what the breakers add up to. Do a load calculation to see what size service you need. 200 amp is common nowadays.

You do need protection for the wire. Wires need to be set back at least 1 1/4" from the edge of the stud. Any closer and you'll need to provide protection - nail plates for example. No issues with fiberglass insulation.

Except for lighting, consider running 20 amp circuits. It just gives you that much margin. You really can't predict what new devices will come out in a few years and the only cost difference is really the wire.

You can get "stackers" for the wires.

Do keep the CAT5 away from powerlines. If you have to cross them, do it perpendicular.

Plan it out before you start pulling wires.

patented 10-24-2012 01:56 PM

Are you planning on pulling a permit for this? I would hope so, with the extent of re-wiring you are looking at.

Some real electricians will chime in, but I will add my .02 cents. Talk to your inspector about what you are planning on doing with the "bundling" and running multiple cables through holes. In most municipalities, you can run 2-3 cables through a 3/4" hole, but.... in my area you cannot run more than 1 cable per hole. I didnt find this out until after I was done, and had to tear down a lot of wiring and re-do it, which took 11 hours.

If your panel is outdated, you might as well get an electrician in there to replace it with a 200A panel.

patented 10-24-2012 01:59 PM

I personally disagree with running all 20A circuits. 12 gauge wire is a pain to deal with compared to 14. Also, it seems to me like electrical devices are getting more efficient, and requiring less power, as opposed to more, so I see no reason to use 20A circuits.

For example, lighting a room used to take a couple hundered watts, and now only uses about 40W.

jbfan 10-24-2012 02:31 PM

The only thing I would different is not having all the bedrooms on 1 circuit.
I would put the master on 1 and the other two on one.
Does your area require arc fault breakers?

fdmillion 10-24-2012 02:33 PM

I am indeed getting a permit for the final work. We did a little dry wiring in one room but I need to pull it out anyway.

All the city told me I need was to write up a plan for what I plan to do, and it's basically up to the power company to do the inspections and such. So I'll call them and bring some of this to them too.

I already knew you need to put the wire far back in the stud or use a nailguard, so no problems there. Already have drilled a few holes, far back from the front of the stud, and in a couple narrow walls planning to use nailguards.

We already have a new 200A loadcenter ready to go up on the wall, so I was thinking I will have the power company shut down my system, then I can pull down all the old boxes, mount the new one, run my wires into it and then leave it for the final inspector to check out and hook up to the service feed.

I wasn't thinking of using 20A wires for the normal branches. I really don't see a need. I do run a lot of electronics in the living room which is why I was going with two 15A circuits there.

Quick Q, on what circuits would I want to use AFCI? I could throw them on just to be safe, even if it's not 100% required. I basically want to do this right, and make it as modern and safe as possible.

Will poke in with more questions if I come up with anything.



jrclen 10-24-2012 03:31 PM

Dining room needs a 20A circuit.
Laundry area (washer) needs a dedicated 20A circuit

I am guessing you mean to place each bedroom on a separate 15A circuit?

I use 15A circuits except where a 20A is actually required.

2-3 cables through a bored hole unless local code disagrees. Contact with insulation, no problem. You are up to 18 spaces for circuit breakers. Will you have an electric range? Built in Microwave? Dedicated circuit for the fridge?

I would go with a 30/40 or a 40 space, 200 amp panel.

Box fill is determined by the cubic inch space in the box and the size of the wires. Here is an example:

20.3 CI 2X4 1 device + 8 wires 14 ga. 1 device + 7 wires 12 ga.
32 CI 4X4 2 devices + 12 wires 14 ga. 2 devices + 10 wires 12 ga
20 CI 4" round box - same as 2x4 (10 wires and 9 wires without devices)
Basically all wires (not cables) entering the box each count as one. A wire passing through without splicing counts as one.
A wire contained within the box does not count. Pigtails and such.
Each set of grounding wires count as 1.
A device (switch or receptacle) counts as 2.

AFCI, check your state and local code. Basically they go on every 120V circuit except the kitchen and bathrooms.

fdmillion 10-24-2012 05:41 PM

Sounds good. Easy swap, since I already provisioned for four 20A circuits, so can run 15A to the bathrooms and run 20A to the laundry and dining room.

Does the washer circuit have to be dedicated? I have 3 rooms in the basement and was basically plan to share 2 circuits between them. I would think maybe I could share the washer and water softener? Maybe I'll have to run a third circuit in the basement for general use? I am aware of the circuit and outlet spacing requirements on main-floor living areas, but not as much for basement. Furnace blower will be on a dedicated circuit.

No electric range, unless you count an electric-ignite gas range as electric (it runs on 110 so not worried about it really). Was thinking dishwasher and microwave on one circuit (those two would not be run together), fridge, range and maybe disposal on the other? Unless there's a good reason to run a third circuit just for the fridge, don't see it being a problem in ampacity especially with 20A circuits(Opinions on this welcome.)

The box I already picked up is a 20-position (40 max breakers) 200A loadcenter.

Am I supposed to, or required to, use any of the 20A outlets (with one prong rotated)? I don't have anything that uses such a plug. I'm running 12/2 wire for 20A circuits so I could always replace the outlet later if it ended up being needed, but for code compliance and inspection, will they want me to have those already?

Also, just noting, got GFCIs, for the kitchens and bathrooms, was thinking of having the entire circuit runs in those rooms protected off the GFCI.


k_buz 10-24-2012 05:52 PM

Some things not to forget.

Smoke/CO detectors
Micro (usually a separate 20A circuit)
Dishwasher/Disposal (usually one 20A circuit, but you will need to check the specs)

parman 10-24-2012 05:59 PM

Ok, Hope this does not turn out long, but it probably will.

I see you are from MN. I am a MN electrician but I really don’t know residential requirements fully. That being said, I can give you some basic info. This info is not all inclusive, just a guideline.

I don’t know where in MN you are, but I have never heard of the Utility doing interior residential inspections. The Utility will inspect and ok the wires/conduit/meter pan, all mounted outside before they connect their lines to bring you power.

The Utility will not connect their lines until you have a passed interior inspection done by a State of MN Electrical Inspector. Which means you have to get a permit from the State of MN BEFORE you do any work on your electrical system. Read the above closely…People try to cheat and redo their electrical without a permit and inspection only to find out the Utility will not hook them up unless they have an inspection by the State of MN

Ok, MN is on the 2011 code cycle. Go buy a 2001 NFPA 70 Code book. You will need it. Then be prepared to not understand anything you read. The code book is kind of cryptic.

Find a Residential electrician that will be your friend. Tell him/her what you are doing and beg/plead to help with any and all multiple and numerous question you will have. Buy them a beer, steak dinner, whatever. You will need help.

You will need to do a load calculation for your house before you start. I cannot say for sure, but you probably will only need a 100A service. You can get bigger if you want, but you will not pass inspection with a smaller than calculated service. Look at Code article 220 for calculations.

You will need to bring your circuit neutrals for lighting down to your lighting switch books per Code article 404.2

You will need Tamper Resistant receptacles in various locations – Article 406.12

Find out how to handle smoke alarms and if interconnection is required and what circuits you can and cannot use to feed them.

Look at Code Article 210.4 for rules on Multiwire Branch circuits.

Look at Code Article 210.8 for GFI receptacle requirements.

Look at Code Article 210.11 (C) (1) (2) (3) for information on Kitchen, Laundry and Bathroom circuit requirements.

Look at Code Article 210.12 for AFCI requirements.

Look at Code Article 210.52 for receptacle location requirements.

Ok, good luck.

k_buz 10-24-2012 06:05 PM

Do not use multi wire branch circuits. With the mandate of AFCI breakers, and the limited availability of 2 pole AFCI's you will be happy you ran all 2 wire circuits.

gregzoll 10-24-2012 06:05 PM

Dining can actually be included in the SABC (Small Appliance Branch Circuit) count for the Kitchen/Food prep area. That also includes the food pantry. Lighting I would look at keeping those loads separate from receptacles. Who wants lights to go out, when you trip the breaker on the wall in a bedroom or family room.

How many square feet is this place, and how many floors including basement? You really need to do a load calc to get an idea of your total load. As for what rooms are going to be wired how, keep in mind with Kitchens, that you may need more than 3 circuits for counters, depending on what you plan on doing in there.

You could end up in the kitchen with a circuit for a microwave, a circuit for the fridge, one for the dishwasher, one for the garbage disposal, one for the fan over the stove, one for the stove in electric, and so on. A modest kitchen could have as little as 3 to 5, a larger could end up with 12 or more circuits depending on how much stuff is going on in there.

You could go from say 12 circuits in a panel, and when you get done, have over 30 or more, depending on how you break stuff down. With CFL's, you could have say 2 lighting circuits in a house.

Post a drawing of your floor plan, and a list of the current circuits that you have now with current amperages. Then post your future floor plan how you will or may want to wire the house, and a dream list of what the Kitchen circuits are going to be.

sixspeed 10-24-2012 06:12 PM


Originally Posted by fdmillion (Post 1037109)
  • 30 amp 220 feed to subpanel for detached garage (this will probably have to be redone, right now looks like just a run of somehow-armored 12/3 suspended overhead outside between house and garage)

The mention of this particular circuit brings up the importance of knowing how to properly install a GROUNDING system for your main residence as well as for any DETACHED structures to which you'll be running electrical feeders or branch circuits. You should also know where to properly BOND, especially if you are dealing with multiple sub-panels and multiple utility services. You should know the minimum ampacity requirements for sub-panels as well.

Your project is a major endeavor for any non-pro. So take your time to be sure you're doing things right. :thumbsup:

jbfan 10-24-2012 06:43 PM

Sounds good. Easy swap, since I already provisioned for four 20A circuits, so can run 15A to the bathrooms and run 20A to the laundry and dining room.

bathrooms require 20 amp receptacle circuits.

sonicsmooth 10-25-2012 02:06 AM

Cat 5 is not going to care how closely you run it to the main wiring, at least in terms of interference. It's twisted pair so any common mode noise coupling in will not be seen by any equipment, and anyway that's only 60Hz plus whatever junk a noisy motor, etc., throws on the line, both of which are well below the 10's of MHz that networking equipment listens to. I think however somewhere in the code it says something about not putting low voltage in the same joist holes as high voltage, but I think that applies to boxes and not necessarily holes in the joists.

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