Electrical wiring question

**Amy Leigh Baker** · 08-05-2008, 8:55 AM

If the power for a light fixture is coming directly into the ceiling box, and I have one (1) 14-2 wire running from the light fixture to the switch, I can't run additional switched light fixtures off that switch, can I? I would have to have another wire running into the switch with a ground and neutral, correct?

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Thanks,

Amy

**Rod Sheridan** · 08-05-2008, 9:01 AM

No Amy, you cannot since there is no neutral in that switchbox.

You could run additional switched fixtures from the wiring in the existing switched fixture however.

If you really want to run other fixtures from the physical switch box, the wire from the exosting switch box to the existing switched fixture would have to be changed to 14/3 to provide a neutral in the switchbox.

Regards, Rod.

**Rob Russell** · 08-05-2008, 9:08 AM

I agree with Rod.

Given the current wiring setup (i.e., without replacing the cable from the fixture to the switch) the only way to add additional switched fixtures is to feed them from the fixture box because you have both the switched hot and neutral in that fixture box.

FYI, Rod was correct about something else. You would need to replace the 14/2 with 14/3 - you can't just run another single conductor. For the kind of wiring we're doing, all the conductors for a circuit must be in the same cable assembly.

**Amy Leigh Baker** · 08-05-2008, 9:16 AM

Okay, so I just put up drywall over the fixture and I would really hate to have to take the full sheet down.

You see the cable that runs power to the next room? Can I run an additional 14-2 from that line to the switch box to power the additional fixtures? I know it might seem a little strange, but I am in the process of a remodel and there's a junction box down the line a little bit and it's closer to the wall in the middle of a half sheet of drywall. That would make it the configuration of the drawing, plus two more switches making it a triple gang box with another 14-2 running into the switchbox through the other two switches and out to power the two new fixtures.

BTW, I currently have no drywall on the walls. I redid the ceilings first and now the walls.

**steve reeves** · 08-05-2008, 10:00 AM

you can run several fixtures from the one switch so long as you don't exceed the amperage rating of that switch... it would take several multi bulb fixtures to do that... however, there may be other items on the same circuit such as outlets, etc.

There are several ways of doing this. all the switch is doing is connecting the hot wire back to itself... you can run additional hot (usually black wire) back to the switch and from there to the fixture.

I'm not sure that this is the solution to your question or not... as I'm not sure that what you're asking is practical... you'd be using a switch in one room to control lighting in more than just that room?

**Rob Russell** · 08-05-2008, 10:12 AM

Amy,

You can sort of do what you want. It's perfectly acceptable to have multiple feeds into a switch box. In this case, they are all on the same circuit, so when you kill power to the circuit - the entire switch box will be dead.

Are you planning the new switch(es) for wall-mounted lights? If so, do you want to be able to control them individually (is that why 2 new switches)? If "Yes" to the individual control, unless you will have (3) new 14/2 cables (1 to supply power to the switches + a neutral, 2 to run out to the new fixtures with power and neutral for each fixture) - then you will need some 14/3 and we'd need to layout how you're wiring things.

When you say "junction box", I assume you mean a receptacle or fixture box - not a plain-front box that's in the wall. Is that correct?

Rob

**Wright Woodall** · 08-05-2008, 11:10 AM

Amy,

I know this is kind of a standard answer, but do a google search for "wiring diagram", and there are a couple of good sites that come up. I have done a lot of wiring in a renovation in Auburn and another one right down the road in Opelika, and I always have to consult one site or another as electrical work doesn't come naturally to me.

Wright

**Amy Leigh Baker** · 08-05-2008, 4:17 PM

Originally Posted by Rob Russell

Are you planning the new switch(es) for wall-mounted lights? If so, do you want to be able to control them individually (is that why 2 new switches)? If "Yes" to the individual control, unless you will have (3) new 14/2 cables (1 to supply power to the switches + a neutral, 2 to run out to the new fixtures with power and neutral for each fixture) - then you will need some 14/3 and we'd need to layout how you're wiring things.

When you say "junction box", I assume you mean a receptacle or fixture box - not a plain-front box that's in the wall. Is that correct?

Rob

The new sketch should explain everything a little better. The dotted lines are wires I have yet to run. The wire to the porch lights and floodlights will be easy since the drywall is off the walls. Both porch lights will be switched together, and the same for the floodlights. It's the one from the junction box to the switches providing full power to the two additional switches that I forgot and will be a pain.

So in the final setup the dining room light will be powered by one (1) strand of 14-2 to the switchbox and the power for the porch and floodlights will be run to the switch box with 14-2, then wire to each of the two fixture circuits will be run with 14-2 (or 14-3 just in case I decide to put ceiling fans at the porch lights later on.

Yes, the junction box I speak of is a receptacle box mounted in the ceiling with a blank plate over it. I couldn't replace the whole run of wire and I wanted to be able to access it later anyway.

Back porch wiring.jpg

**Wright Woodall** · 08-05-2008, 4:58 PM

Originally Posted by Amy Leigh Baker

The new sketch should explain everything a little better. The dotted lines are wires I have yet to run. The wire to the porch lights and floodlights will be easy since the drywall is off the walls. Both porch lights will be switched together, and the same for the floodlights. It's the one from the junction box to the switches providing full power to the two additional switches that I forgot and will be a pain.

So in the final setup the dining room light will be powered by one (1) strand of 14-2 to the switchbox and the power for the porch and floodlights will be run to the switch box with 14-2, then wire to each of the two fixture circuits will be run with 14-2 (or 14-3 just in case I decide to put ceiling fans at the porch lights later on.

Yes, the junction box I speak of is a receptacle box mounted in the ceiling with a blank plate over it. I couldn't replace the whole run of wire and I wanted to be able to access it later anyway.

Back porch wiring.jpg

Amy,

Is there any reason not to run the power to the outside fixtures and then run switch legs back to the switches? It will not solve your problem of getting back to your junction box above the drywall, but I have found that feeding a circuit through the switch box makes that box get full quick. There usually seems to be more room behind the fixtures than behind the switches. Just my 2 cents.

Do you think there is any possibility of running a fish tape above your drywall to run the new wire to the junction box so you don't have to pull the drywall down?

Also, why would you need 14-3 for ceiling fans? As I said before, i'm no electrical engineer, but I think all my fans are run off 14-2.

Wright

**Rob Russell** · 08-05-2008, 5:43 PM

Amy,

What you are proposing will work just fine and meets most code requirements. Mind you, I'm not a licensed electrician - just an anal nut who likes to read the National Electric Code (NEC) and has done a lot of wiring (I wired the 1000' sq ft addition to our house including subpanels). Note that by "code", I mean the NEC which is a baseline model. The "code as adopted" by the local "Authorities Having Jurisdiction" (AHJ) varies. Some places are really lenient when it comes to code, others are stricter.

A few things to be careful about:

The "junction box" on your diagram needs to be large enough from a "conductor fill" perspective. #14 needs 2 cubic inches per conductor entering or exiting the box + 2 cubic inches for all of the equipment grounding conductors (EGCs) combined. You have at least (6) #14 conductors + the EGCs, so that's a minimum of:

((6) conductors + EGCs) * (2) cu/conductor = 14 cubic inches.

The smallest boxes you can typically buy now are 14 cu so that just fits, but if you reused an older box - it could be smaller. That would mean digging out that old box and replacing it with something larger. If you have other parts of the circuit that run though that box, you need to check the box size. If you have more than what's shown in your diagram, post a diagram of what you can see entering and exiting the "junction box" and I (or someone else) will give you the box size requirements.

Another thing to consider is whether or not you will ever want to put a receptacle there for a light that just plugs in to the receptacle or fish a cable through to feed a light. If you have a 14 cu box - it's full now.

If you think you may replace the porch lights with ceiling fans, make sure that you use "ceiling fan rated" boxes now. Those are designed for the weight and vibration of a fan. You may never put fans out there (although I wouldn't take that bet considering you're in Alabama), but if you ever want to - code does specifically require boxes rated for fans.
If the outside porch is "exposed to weather" or "damp", you may want to check with your local building inspector to see what they require for wiring. It may means direct burial or other "damp location rated" stuff, which would be a real nuisance. The point is that NM-B, isn't rated for "damp" locations. An "open or expsed porch" is considered "damp". If your porch ceiling is covered with anything (plywood, beadboard, etc.) - I believe that becomes a non-issue, but check with the local code weenies.
FYI (and this is REALLY picky, so forgive me), a cable isn't called a "strand". That's a single cable. A strand is one of the small wires that's part of a single "stranded" conductor. If you look at NM-cable (aka "Romex"), the conductor is a single "strand" of metal. When you get up to larger stuff like anything larger than #10, the metal inside the insulation is made up of a bunch of smaller wires all twisted together. Those small wires twisted together are individually called "strands".

I'm only pointing that out so you don't go into a big box store or electrical supply house and ask for a "single strand" of cable because it'll make you look like you don't know what you're doing. You are already tackling WAY more than many guys and most women do. I applaud you for that effort because I, personally, think wiring's fun.

I'm happy to provide NEC code cites if you want the code references behind what I've cited you here for points #1 and 2.

Beyond that - you've got a great plan going! Hapy wiring. I really do love this stuff! You should see the wiring diagram for our addition. Our GC told me that it would have been a $10K - 15K job for what I did (very sophisticated lighting and other wiring).

**Shaddy Dedmore** · 08-05-2008, 5:47 PM