7 Tricks For Getting Wires Into Electrical Boxes

Installing Electrical Outlet
Installing Electrical Outlet. Getty / Image Source

One of the more frustrating aspects of electrical work is pushing wires into the box after you have connected the device.  Boxes always seem to be too small, devices too big, and wires too numerous.  

It can be done with some of the tricks here (and in other instances, it should not be done, and we will cover that, too).

1.  Stay Within Box-Fill Capacity

You know this already, but it has to be said:  electrical boxes have limits as to how many wires they can accommodate.

 

Box-fill capacity is printed in tiny letters on the inside of plastic boxes for different gauges of wire.  For metal boxes, a few common box-fill capacities are:

Electrical Box Fill Capacity - Metal
Box Size (Inches)14 Gauge12 Gauge
4 x 1.2598
4 x 1.50109
4 x 22118
3 x 2 x 1.533
3 x 2 x 254
3 x 2 x 2.2554
3 x 2 x 2.5065

 

2.  Bring Down Your Wire Gauge If Appropriate

Do you really need 12 gauge for that circuit?  Dedicated lighting circuits, for example, only need 14-gauge wire and a 15A circuit breaker.  The 14 gauge wire allows more wires per box and is far easier to fold than 12 gauge.

3.  Change Out For a Bigger Box

Maybe you cannot go wider, but you often can go deeper.  A prime example is the common plastic "old work" or remodel box, the type of box that clips onto drywall rather than attaching to a stud.

You might have picked up the first remodel box you saw at Home Depot--the 14 cu. in. single gang box.

 But there is also a single gang 20 cu. in. box that does the same thing, only better.  

As long as you have enough space in your wall cavity, there is no reason you should not get a deeper box, making it easier to stuff in the wires.

4.  Cut Your Wires Longer

This is the weirdest, most counter-intuitive piece of advice:  to better fit wires into boxes, use more wire.

 

No, do not use a greater quantity of wires.  Instead, provide longer sections of wire sticking out of the box.

This makes the wire easier to fold, and folding is the way to get wires into boxes.

5.  Fold Instead of Stuff

With 6" of wire protruding from the box, it is possible to make one or two good folds in the wire, accordion style.  With short wire, you cannot do this.  Besides, longer wires make it easier to connect the device.

6.  Use an Aid For Folding

Use a wooden shim or a screwdriver handle to make a sharper fold in the wire.  Just be careful not to put undue stress on the wire.

7.  Reduce Sheathing In Your Box By Ripping It First

Too much sheathing--the thick plastic coating that binds multiple wires--only steals room from your electrical box.  You only need 1/4" protruding inside the box.

If you rip sheathing with the wire in the box, it is nearly impossible to cut it to 1/4".  Instead, insert the cable in your box, mark the entry point with a Sharpie, remove, and rip to the proper length.