box fill calcs - am I doing this right?

[Nate Nagel]

Am trying to properly plan attack on wiring...

want to use fan rated boxes for ceiling boxes in 2 (eventually 3) bedrooms

from this site:

looks like a 2-1/8" deep octagon box is 21.5 in^2

cable coming in = 2 conductors cable to next ceiling box = 2 conductors switch leg = 3 conductors (I hate pull chains) ground = 1 wires to light fixture = 2 (most ceiling fans have canopies, otherwise I'd have to allow 3 for a possible future fan) clamps = 1

so my total is 11 "conductors"

looks like this doesn't work? 11x 14AWG conductors requires 22 in^2?

Even worse, at some point I have to tap off for the receps... guess I have to do that in the hallway with a regular box and extension ring?

am I missing something? My wiring doesn't seem all that unusual, and I

*really* am trying to avoid having to use boxes in the attic, that's what prompted the "all right, let's just go ahead and repull this" exercise in the first place (am still trying to complete my sketch of how all the existing wiring is run, need to go back up and double check a few things...)

Am thinking perhaps I don't have to allow for the clamps since the box uses knockouts and the clamp is physically outside of the box?

I'd just go ahead and put extension rings everywhere EXCEPT for the fact that SWMBO really wants ceiling fans in all the bedrooms. And it does seem like it would be a nice feature if we ever went to sell the place...

nate

[Nate Nagel]

Hmmm... possible workaround.

the boxes I have use 10-24 screws into the *back of the box* for the fan support not ears like the regular fixture screws.

Could I use a regular extension ring on the ears, and then if I get a fan on down the road, use a pair of 1-1/2" longer 10-24 screws than whatever the box was supplied with? That seems like the way to go, unless this is unacceptable for whatever reason.

nate

[Pete C.]

Don't feel like looking it up, so I can't comment on box fill, however I have a suggestion that could reduce the fill - get a remote controlled fan or module for the fan and save the switch leg hassle.

[Doug Miller]

Ten 14ga conductors @ 2 in^3, or nine 12ga @ 2.25 in^3.

Why 3 conductors for a switch leg, not 2?

Fixture wires don't count.

9

Right, but you have at most 9, and probably less.

That's corrrect -- if the clamp is outside the box, it's not counted in what's inside the box..

[Metspitzer]

You don't count the two fixture wires. The count is for conductors entering and leaving the box.

I would not put an extension ring on a box I plan to use for a ceiling fan.

[John Grabowski]

*Nate you will be fine with the deeper box. No need for an extension. A Romex connector with the clamp outside of the box does not count. Many fan boxes come with plastic button connectors which also don't count. In addition, for a ceiling light and in your case a ceiling fan, the canopy cover that is part of the light or fan adds to the cubic inch capacity.

The other alternative is to bring your two wire feed into the switch box and feed the other fan from there in addition to your switch legs. If the wiring is going to be in an accessible attic space you could also put a junction box up there. Make it easy for yourself.

I personally prefer not to have the ceiling box used as a junction box. If there is a problem it is easier to troubleshoot a splice in a switch box or a junction box instead of having to remove a fan. I have also found that customers tend to relocate lighting after so many years and it is easier to move a box that has one cable. I also prefer to have a neutral at the switch box for some of the new controls and timers that are available. In addition I have many memories of pulling down old light fixtures and seeing the insulation on the wires so crispy from heat that it falls off as soon as you touch it.

[Nate Nagel]

Future ceiling fan installation. Figured on installing a dual light/fan switch in the wall box if that ever happens. Did I mention that I hate pull chains? Personal quirk I guess.

This is why I was asking, I don't do this professionally, so I wanted to make sure I was good. The way the code is written (I looked it up) it seemed to imply that I needed to allow for them.

thanks, appreciate the help

nate

[John Grabowski]

*I normally use three wire cable for fans and install two wall switches. One for the fan and one for the light attached to the fan.

[Nate Nagel]

Exactly. I figure I'll use the red for the light and then the white will just get capped and left unconnected at each end. That way if I install a fan, I can install a double switch at the wall end and reidentify the white as a switched hot *or* if down the road someone decides they need a neutral at the switch box they can do it that way as well.

Believe it or not I actually hate doing this stuff, but it needs to be done. otherwise I'm going to end up in a house full of never quite finished projects, GFCIs and stickers everywhere, "only plug your computer in the one outlet in the little bedroom" etc.

nate

[Joe]