Wiring Techniques?

[Steve Mathews]

While rewiring my shop it didn't take long to realize my wiring techniques could stand some improvement, especially in the area of stuffing junction boxes. I'm getting fairly good at folding 14 and 12 gauge wires for duplex outlets. I use 3 folds for each wire. The first fold is opposite where the wire enters the box. The 2nd fold is at the other side of the box. And the last fold is more subtle than the others before it lands on the terminal. I usually leave about 7 inches of wire in the box. My efforts in getting 10 gauge wires with pigtails folded in a box are far less successful. It looks more like a rats nest after finishing. So, what techniques do you use to make your wiring look good? I've seen professional electricians do wiring that looks good and some not so good. The word professional isn't synonymous with the word craftsman.

[Sam Layton]

10 gauge wire is tough to handle. I used 10 gauge solid wire for my runs, and 10 gauge stranded for the pigtails. The stranded is a little easer to work with. I also use double gang boxes with a single gang reducer for the plug and face plate. The double gang box gives you a lot more room.

Sam

[Jim Becker]

I agree with Sam on the 10 gage stuff...bigger box with a smaller face gives you room to work. The only reason I was able to avoid that in my shop was that I home run my 240v circuits with a j-box in the middle somewhere to be able to re-route to a different location should my needs change and not require doing anything on the breaker side wiring that crosses wall boundaries, etc.

[Alan Schaffter]

Codes (NEC and/or local) in most areas of the country determine what gauge and how many wires/connections/circuits (sometimes the definitions are not self explanatory), how long, etc. you can have in what size electrical box. 10 gauge likely requires larger than a standard depth/size duplex outlet box. You might want to check code or consult with an electrician.

If you are in an area where a license is required to do electrical work (Montgomery County Md, Chicago area, etc. etc.) and you do it yourself, your insurance may not pay if you have an electrical fire, etc. and need to file a claim.

[Van Huskey]

You need a bigger box... at least that is what makes it easy. I've terminated 10ga in 18 in^3 boxes but only home runs if you are pigtailing you need (a lot) more room

[Matt Putnam]

I also use double gang boxes with a single gang reducer for the plug and face plate.

Sam
I likely will need to do the same - using a double gang box with a single gang outlet/plate for the tool connection. I was at the orange big box store this morning and didn't readily see a reducer. Is this something easy to locate? Could you post a picture if you have one around?

[Steve Mathews]

The fill in my 2 gang 32 cu. in. box is either 33.25 or 31 depending on how the ground wires are interpreted. Here's what's going into the box ...

2 - 12/2 conductors, 1 in & 1 out
2 = 10-2 conductors, 1 in & 1 out
2 - 12 gauge ground conductors pigtailed to duplex outlet
2 - 10 gauge ground conductiors pigtailed to single outlet

Any opinions on the fill calculation of the ground wires?

Fortunately I live in an area where one can exercise some degree of self determination without government intervention.

[Chris Padilla]

I use the 4 11/16" x 4 11/16" boxes wherever I can so I'm not fighting fill issues and general room issues. They aren't as easy to install in a wood frame as I've never seem them come with the extra "nail to the stud" legs but the large volume is VERY nice.

Steve, there is a link to the NEC at the top of the forum here where I'm sure the verbage exists to calculate what you want. Do a search on CCC (current carrying conductors) and you'll probably get real close to finding that verbage. :)

[Jim Becker]

I likely will need to do the same - using a double gang box with a single gang outlet/plate for the tool connection. I was at the orange big box store this morning and didn't readily see a reducer. Is this something easy to locate? Could you post a picture if you have one around?

The covers that support a single outlet centered in a dual box tend to be metal and fit specific boxes.


http://www.homedepot.com/catalog/productImages/1000/0b/0bca5faf-da16-4651-87c1-3894f2ea34fe_1000.jpg

[Steve Mathews]

Steve, there is a link to the NEC at the top of the forum here where I'm sure the verbage exists to calculate what you want. Do a search on CCC (current carrying conductors) and you'll probably get real close to finding that verbage. :)


The link to the NEC is no longer active and should probably be deleted.

The only issue is how the ground conductors are counted. If both 10 and 12 gauge grounds are bonded and pigtailed then it would clearly only count as 1. But I have separated the grounds for each gauge and used pigtails to their respective outlets. I suspect the lesser count of 1 is correct based on the number of bonded grounds not impacting the count. So based on that interpretation the fill calculation would be as follows.

6 (12 gauge) x 2.25 + 7 (10 gauge) x 2.5 = 31

A 32 cu. in. double gang box should be sufficient.

[Matt Putnam]

Thanks, Jim. I see that cover has corner holes for mounting to the box. I do see metal square boxes at big box store that I think would work but it seems a blue plastic double gang box would not work as they don't have the corner holes. Sound right?

[David L Morse]

Thanks, Jim. I see that cover has corner holes for mounting to the box. I do see metal square boxes at big box store that I think would work but it seems a blue plastic double gang box would not work as they don't have the corner holes. Sound right?

There are plastic boxes that use that style of cover plate, this one (http://www.menards.com/main/electrical/electrical-boxes-covers/electrical-boxes/legrand-reg-slater-reg-4-35-0-cu-in-gray-square-nail-on-box/p-1444451213127-c-6425.htm?tid=-864409900906792174&bargainStoreId=3511) or this one (http://www.menards.com/main/electrical/electrical-boxes-covers/electrical-boxes/legrand-reg-slater-reg-4-35-0-cu-in-gray-square-bracket-box/p-1444451218694-c-6425.htm?tid=-864409900906792174&bargainStoreId=3511) for example. I don't know if they're available in blue.:)

[Robert Engel]

Usually a 4x4 box you can always add an extension to it or go with a deep box.

[Jim Becker]

Thanks, Jim. I see that cover has corner holes for mounting to the box. I do see metal square boxes at big box store that I think would work but it seems a blue plastic double gang box would not work as they don't have the corner holes. Sound right?
Yes, that particular cover wouldn't work with the typical blue plastic boxes so you'll want to match the boxes and covers for the application. I just posted that photo as an example so you understood what I and others were referring to.

[Matt Putnam]

Thanks, guys.
I was back at the my usual big box store today, checked this thread on my phone, saw David's reply, and then looked right up and found the plastic box I needed - and it was blue! I used the color just to describe the plastic ones I normally use but don't care about the color. Not sure how I missed it last time.

[Dan Rude]

If you want to use the bigger boxes, go to a electrical supplier. They also make the covers that fit. You will be paying a small premium. You might also consider an http://www.homedepot.com/p/8-in-x-8-in-x-4-in-NEMA-1-Enclosure-SC080804RC/100537130 I had to use one of these for my Basement master light switch install. I needed the size due to wire fill count. Also Stranded wire is much easier to fit in any box. It does cost more, but is definitely worth it for convenience. Dan

[Steve Mathews]

My small electrical project is now finished. The duplex outlets are spaced 4 ft. apart on 2 alternating 20 amp circuits. The 20 amp, 240v outlets are spaced 8 ft. apart and share the same box as one of the duplex circuits. As mentioned before the 10 gauge wire on the 240v circuit was the most difficult to install but with a little thought, practice and advice offered here it went well and looks good. I think the key to working with the 10 gauge wire is knowing where to make the folds and using a piece of wood to help the process. A larger box other than the 32 cu. in. duplex box that I used would've made the job easier but wasn't necessary in my opinion. I really like the 120v duplex outlet and 240v outlet in the same box. It looks less cluttered than providing separate boxes. Rather than buy a special cover plate I took a standard duplex/switch cover plate and cored a hole over the switch opening for the 240v outlet. Luckily the screw spacing was the same. I was planning to paint some of the cover plates to identify their circuits but found it wasn't necessary because the combination 120v and 240 outlets grouped together do that for me. The bonus to this project besides having a better laid out work space is that I learned a few things along the way and picked up a few skills.

[Rollie Meyers]

The problem w/ DIY electrical installations is DIYers propensity to use handy/gem boxes, it's like trying to stuff 10 pounds of manure in a 5 pound bag, my attitude towards them is if you want to use them, spread your hands out on a anvil, & have someone hit each finger ten times with a 5 pound hammer, after that & think it's still a good idea, go ahead. :D As one can guess I hate them, proper/generous box sizes make the job easier.

[Steve Mathews]

The problem w/ DIY electrical installations is DIYers propensity to use handy/gem boxes, it's like trying to stuff 10 pounds of manure in a 5 pound bag, my attitude towards them is if you want to use them, spread your hands out on a anvil, & have someone hit each finger ten times with a 5 pound hammer, after that & think it's still a good idea, go ahead. :D As one can guess I hate them, proper/generous box sizes make the job easier.
What's a proper/generous size double gang box larger than 32 or 34 cu. in. that will fit in a 3 1/2 stud wall?

[Chris Padilla]

The 4 11/16 x 4 11/16 x 2 1/8 is 42 cubic inches.

One can pack 16 #10 or 18 #12 or 21 #14.

http://www.wireityourself.com/box.html#.WJi4y385aZY

[Steve Mathews]

The 4 11/16 x 4 11/16 x 2 1/8 is 42 cubic inches.

One can pack 16 #10 or 18 #12 or 21 #14.

http://www.wireityourself.com/box.html#.WJi4y385aZY

And then there are 5 square boxes with even more capacity but both wouldn't fit my needs because a combination duplex/single 20 amp cover plate wouldn't fit. In response to Rollie's comment about DIY installations, the problem with for profit professional installations is often times you get shoddy work and never better than what I can do myself.