household wiring

[zahc]

I want to add 2 circuits, because I am converting my 2 upstairs closets into a washroom and an office.

There are several slots empty on my service panel, so I could pop in 2 15A breakers. The service panel is mounted in the exterior wall inside of a downstairs closet, on the opposite end of the house. By punching through the ceiling of the closet several feet away from the service panel, I can go up through a second-story interior wall right to the attic, and then I can run the wire across the attic and down into the rooms needing wired.

I looked up the codes for running the wire through the attic, and I gather that it's ok to run romex loose up through an interior wall without fastening it to the studs if you are retrofitting wiring after the wall is closed up. The question is what kind of wire I need (14 or 12g, 2-conductor or 3) and how to run the wire from the service panel up through the ceiling of the closet. I can punch through the drywall right next to the service panel and run the wires out of the wall next to the service panel, across the closet wall, and up to the ceiling of the closet.  Is it possible to do this if I use conduit? Is it fine to use 14ga wire for a 15A circuit that is on the other side of the house?

[lee n. field]

Is it fine to use 14ga wire for a 15A circuit that is on the other side of the house?

It's been a while, but my recollection is, no.  12 gauge.

[Azrael256]

14ga will carry 20A (or more depending on the insulation type), but 15A is as far as I'd go with it.  My NEC chart is pretty old, but I doubt it changed for 3-conductor Romex.  You may run into a problem with voltage drop if "the other side of the house" is more than 30' or so, but you'll probably still be in spec with a small drop.

I don't like your plan, but I'm a serious wire neatness nazi.  There has to be a way to get to the box from above, it just might require a fiberglass rod and a special drill bit.

[Cliffh]

Is there some existing wiring coming down from above the service panel?  You might have to break into the drywall in the room above the box to see if there is.  If so, can you snake the new wiring down to the service panel alongside the existing wiring?

Personally, I'd opt for 20 amp service and run 12ga Romex.  That would be 12/2 w/ground.  If you decide on 15 amp service, you could use 14/2 w/ground.  The 20a service might not be necessary right now, but the cost wouldn't be that much more and would give you more options in the future.

[cassandra and sara's daddy]

what he said^
12 gauge 20 amp everywhere

[geronimotwo]

in general,  14ga for 15a,  12 ga for 20a,  10ga for 30a.   use conduit where exposed in the closet,  and covered junction boxes for any splicing/splitting   all boxes must be accessable for future maintenence/troubleshooting.  twist wires then wire nut them, including grounds.  2 wire plus gound will be fine for 120v.

[zahc]

I don't like your plan, but I'm a serious wire neatness nazi.  There has to be a way to get to the box from above, it just might require a fiberglass rod and a special drill bit.

Well, like I said, the service panel is in an exterior wall. It's a brick house. I can see wire coming down into the top of the service panel from elsewhere in the house, but I really doubt any of it runs down from the room above because there's nothing but an 8x8 closet directly above. If I wanted to rip out the drywall in the 8x8 closet above, I could drill down through the subfloor within the exterior wall and run the wire up through there into the attic--probably; I'd have to look in the attic. But I'd much rather not rip out that drywall. If I can just run the wire over a bit I can go up through the interior wall. I'm not concerned about wire neatness that much because it's inside the closet; I'm mainly worried about doing it safely, and to code if possible.

I will use 12/2 romex. What's the point of the 3-conductor wire? It seems like the only reason you would need 2 hot wires is if you wanted 240V.

[Cliffh]

What's the point of the 3-conductor wire? It seems like the only reason you would need 2 hot wires is if you wanted 240V.

IIRC there are times were more wires are needed, i.e. when wiring in two light switches to one light.

I'm pretty sure you can run wiring on the outside of the wall using conduit and still be within code in most places.  The box stores (Home Depot, Lowes, etc.) sell a semi-decorative metal or plastic conduit that can be used to add new receptacles, switches etc.  There are all sorts of fittings for it; inside and outside corners, box extenders, receptacle boxes and others.  I've used it a couple of times, works and looks OK.

[Jim147]

You might want to double check your incoming service and your service box rating. Just because you have space to add more breakers doesn't mean it's safe to do.

jim

[Hawkmoon]

I want to add 2 circuits, because I am converting my 2 upstairs closets into a washroom and an office.

There are several slots empty on my service panel, so I could pop in 2 15A breakers. The service panel is mounted in the exterior wall inside of a downstairs closet, on the opposite end of the house. By punching through the ceiling of the closet several feet away from the service panel, I can go up through a second-story interior wall right to the attic, and then I can run the wire across the attic and down into the rooms needing wired.

I looked up the codes for running the wire through the attic, and I gather that it's ok to run romex loose up through an interior wall without fastening it to the studs if you are retrofitting wiring after the wall is closed up. The question is what kind of wire I need (14 or 12g, 2-conductor or 3) and how to run the wire from the service panel up through the ceiling of the closet. I can punch through the drywall right next to the service panel and run the wires out of the wall next to the service panel, across the closet wall, and up to the ceiling of the closet.  Is it possible to do this if I use conduit? Is it fine to use 14ga wire for a 15A circuit that is on the other side of the house?

For simple 120-volt circuits, you need 2 conductor plus ground. You get into 3 conductor for 240-volt circuits, or three-way switched circuits. 14-gauge is what code calls for for 15-amp circuits, 12-gauge for 20-amp. However, for length of the house runs, I would use 12-gauge to offset voltage drop.

Romex can be run exposed, as long as you support it every few feet (staples to the wall). Conduit is overkill (and I'm not even sure the code allows running Romex in a conduit, and I don't have my copy of the NEC handy). But I'm also a neat freak about wiring. I would open the sheetrock and run everything concealed before I would even consider running wires exposed OR in conduit in a finished, downstairs closet. That just screams out "Tacky! Done by an amateur!"

How old is your house? Dollars to donuts it's not a "brick" house. I'll bet it's a wood framed house with a brick veneer. Which would mean the exterior walls should have studs every 16" or 24", just like the interior walls.

[Triphammer]

If you have a source to by your NM-B (ROMEX in a brand) cable in lenghts required as opposed to buying full boxes, you can run a 12/3 plus ground & split it into two seperate 20 amp circuits @ your first junction box. If you put the two hot legs on oppsite phases, you can share the neutral between them &  still be well within NEC. For exposed wiring in the downstairs closet you can use E.M.T. or "Wiremold" or similar prepainted channel w/ fittings, but EMT is easier if you have a bender. If you're going to use pipe you may as well punch straight though the closet ceiling and run exposed in the second floor closet into the attic. The NM-B can be run open on exposed rafters in the attic if therer is no floor or easy access. If there's a floor, tuck it over out of the way.

E.T.A.
 You may want to run one or two 20 amp circuits to pick up the outlets, especially in the office, & run a 14 ga. for your lighting circuit. It's a real pain to wire the light fixtures & associated switching in 12. Don't foget that any outlets in the washroom will need to be GFCI protected

[Nick1911]

what he said^
12 gauge 20 amp everywhere

This.  You won't regret having the capacity, and you won't have light-dimming crap going on when you turn something hungry on.

[zxcvbob]

The ampacity of 14 gauge copper wire may be 20A, but the code limits its use to 15A circuits.  So run 12 gauge Romex and 20A breakers even if the intended load is only 15A and you won't have to worry about voltage drop or tripped breakers.

You might can save a little money by using an "Edison circuit" -- 2 hot wires on opposite legs and a shared neutral (and ground.)  This also reduces the voltage drop iff both legs of the circuit are used at the same time.  (you would split it at a junction box in the attic near the new bathroom pretend it was 2 circuits at that point -- run one to the bathroom and one to the office.)  The down side is you have to use a 2-pole breaker, and if one side trips it takes the other down with it.  Also 3-conductor cable sometimes costs more that twice as much as 2-conductor, but probably not the case now with copper prices so high.

[Triphammer]

No, you don't have to use a two pole breaker. For all intents & purposes it is two seperate circuits.

[zahc]

You might can save a little money by using an "Edison circuit" -- 2 hot wires on opposite legs and a shared neutral (and ground.)  This also reduces the voltage drop iff both legs of the circuit are used at the same time.

That sounds pretty smart. I'm trying to figure out how 2 hots and 2 neutral could cause less voltage drop than 2 hots and 2 grounds. It must be something to do with them being out of phase.

If you're going to use pipe you may as well punch straight though the closet ceiling and run exposed in the second floor closet into the attic.

Said closet is actually the washroom-to-be. So it's true that I could punch through the floor and run conduit up into the washroom but it would be ugly in the washroom in addition to the downstairs closet. Whereas, if I can go up through a wall into the attic, I should be able to run wires back down into the walls for the switches and outlets and make it all pretty in there.

[zxcvbob]

Said closet is actually the washroom-to-be. So it's true that I could punch through the floor and run conduit up into the washroom but it would be ugly in the washroom in addition to the downstairs closet. Whereas, if I can go up through a wall into the attic, I should be able to run wires back down into the walls for the switches and outlets and make it all pretty in there.

Why not punch thru the floor at the wall plate inside the wall cavity?  Then you can run Romex cable, all hidden inside the wall.  That's how I usually do old work.

[never_retreat]

You can not by code put romex in conduit. There are certain allowances for short runs but this won't meet it.
There are a lot of different reasons you can not do that.
Heat, wire will warm up during normal use. Trapping the heat can be bad.
Grounding, that pipe needs to be grounded.
Plus some others but I'm not digging the code book out.

Just remember if you run 2 circuits on 14-3 or 12-3 the breakers need to be on different phases of the panel. This keeps the neutral from having a double the current on it.

The easiest way to do this would be to run MC cable to the attic and then switch to romex.

[zahc]

Well today I ran 12/3 MC to the attic. I tapped into the service panel at the bottom with a clamp fitting, then out the drywall about 4 inches away, and then across the closet interior to the ceiling on the other side with clamps every foot. Then I went up the inside of a 2nd-story wall to the attic and into a junction box.

I'm running 12/2 romex to the other side of the house some 50 feet away. Since I'm running the wire anyway, I decided to install 2 pull-chain light fixtures. For the light fixtures, I cut a 6-inch pigtail of wire and wire-nutted the 2 ends plus the pigtail together, and then used the pigtail to hook up to the light fixture. It strikes me my whole office circuit will be running through these wire-nut connections. Is this a problem? I don't think so, but for all I know light fixtures should be on their own dead-end circuit or something.

[Triphammer]

For the lights, I'm assuming theses splices are in junction boxes to which you will attach the pullchain fixtures? As far as the load running through the splices, never has been a problem when the wirenuts ae tight.

[zahc]

I screwed steel ceiling boxes to the wood rafter stringer, and made my wirenut connections inside the box. So my circuit goes through 2 pullchain lights and then to the office where it will be wired up to outlets and switches.

[never_retreat]

Yes the nuts are good. Just make sure you twist the wires before putting on the nuts. It makes a better joint. Also if you are using metal boxes you must add a pig tail to the ground and screw it to the box. All metal must be grounded.

[never_retreat]

Here is a good one.
http://www.break.com/cue-the-cuervo/worst-automatic-garage-door-opener-installation-ever-2020629

[zahc]

On the pull-chain light fixtures, the earth ground hooks up to the fixture with a green screw. The piece of metal the green screw threads into is directly under the screw head that fastens the fixture to the metal box. Is this sufficient or do I have to have a separate pigtail?