How to cram wires into electrical boxes?

[Stephen Tashiro]

Is there a systematic way to get wires crammed back into electrical boxes after you have completed the connections? Can they be folded up in a particular way?

[Jason Roehl]

Electricians typically coil them in the box as much as possible. Folding is not recommended.

[Charlie Velasquez]

Place them as you make the connections. I typically do all the grounds, then put them in, then the current carrying conductors. Then, I am only left with the short pigtails to the device.

If it is pretty tight check the number of conductors allowed in your box. There are online fill calculators that can help.
If you are ok with the number of conductors, the length of the conductors may be excessive. You can gain space by cutting the length and eliminating the twist on wire nuts. Wago connectors use less than half the space of old style wirenuts, and if you’re pigtailing your device Wagos only need a couple of inches of your supply conductors instead of the six or so for wirenuts.

If you exceeded the fill for your box the Wagos may help you but if it is being inspected the inspector will probably make you redo it anyway. In that case, remove the box, remove the wires, get a deeper old work box, and try again.
Or, better, cut the opening for a 2 gang or 4” box, and add another device. You double or triple your volume for the price of another pigtail and outlet.

[roger wiegand]

I use boxes a size or two larger than I actually need for the fill requirements. Especially with larger switches and such the extra elbow room is a benefit. External clamps can save some space vs the ones that are built into a box as well.

Perhaps it's a regional thing, but the electricians here fold the wires like an accordion fold rather than coiling them. I can see that more gentle curves would be better than sharp bends.

[Tom M King]

I use deep boxes where possible, for everything, and leave plenty of wire to connect the device, but a foot of wire is not needed.

[Ole Anderson]

One trick is to use the end of a hammer handle as a cram-them-in device. Those 12 ga wires are a bugger. Of course watch your wire count and box volume.

[Charlie Velasquez]

.....
Perhaps it's a regional thing, but the electricians here fold the wires like an accordion fold rather than coiling them. I can see that more gentle curves would be better than sharp bends.

Curves are better, but folding usually meets code. Radius of bends in conductors should be ≥8 X the diameter of the conductor. For 14g that would be about 1/2”, 12g just a tad more. Grabbing it and bending with your hand, with the side of your little finger as the fulcrum would give a radius of about 3/4”-1”. Pushing into the box will close it up a little more.

[Günter VögelBerg]

I don't think this should be a problem for new boxes that follow the fill rules. I have this problem in my house with older work when I have to replace a device or something.

[Stephen Tashiro]

Is there a good video showing how to coil or fold the wires? The meanings of those terms are clear, but what's the technique?

[Stephen Tashiro]

Place them as you make the connections. I typically do all the grounds, then put them in, then the current carrying conductors. Then, I am only left with the short pigtails to the device.

That's clear advice!



Wago connectors use less than half the space of old style wirenuts, and if you’re pigtailing your device Wagos only need a couple of inches of your supply conductors instead of the six or so for wirenuts.

The local stores only stock "Ideal" brand push-in connectors. The term "push-in" doesn't inspire confidence, but I've never tried them. Your post was the first time I heard about Wagos. I ordered some online.



get a deeper old work box, and try again.

I use big boxes because I'm not doing a big project, so cost per box isn't crucial. It's convenient to use deep boxes, but in a standard 2x4 stud wall, I worry about someone driving a screw or nail into the box or wires from the other side of the wall.

[Mark Bolton]

I have always found if you take your time and build a mental picture in your head of where the conductors will sit in the box and begin to learn to initiate bends you will have a much easier time with heavier conductors. I agree with staging your connections, grounds first, neutrals, then hots/travelers,.. You often times still have to make all those connections outside the box and get them in as a group so the planning and initial bends help a lot.

Something I see here locally a lot is people running 12/2 by default for everything which is simply unnecessary most often. Too heavy a conductor in a crowded box is always a challenge.

Another option is to move to pigtailing everything with THHN pigtails that are more flexible.

Using uncovered buchanans on your grounds or a twisted tail if your inspector will allow free's up a good amount of space in your box.

[Frank Pratt]

Bringing all the cables in either the top or bottom of the box, but not both, is a good strategy for making all the wire fit neatly & take up less space.

[Mark McClurg]

I accordion fold the wires to address the additional length needed for servicing of the device (outlet/switch/dimmer.) If the romex comes in from the top, I fold the 3 conductors at the bottom then again at the top, then do a half-fold out to the device itself. That typically leaves enough spare length to meet code and servicing when needed.

[John Goodin]

The wagos are a little more expensive than typical wire nuts but agree they are much easier for the person who works infrequently with wiring.

[Brian Elfert]

My father was an electrician early in his working life and he neatly folds the wires into the boxes. This is the first I have ever heard of electricians coiling wires in boxes. If you have to beat the wires in with a hammer handle you're probably doing something wrong and may need a bigger box. If you're worried about wires failing from too tight of bends what do think a hammer handle does the wires?

I will be helping my father and brother wire my brother's new house this winter. My brother chose to put the meter and the load centers on the back of the attached garage a pretty good distance from the main house. The runs will most likely need to be all 12 gauge to deal with voltage drop. We are pretty sure code won't allow switching from 12 down to 14 as someone could switch a breaker to 20 amp thinking the circuit is all 12 gauge.

If you think a deep box could get damaged why not use a metal box then?