Learn more in my roughing-in series for electricians.
In this article, you’ll learn how to splice a single gang junction box.
A single gang electrical box (one gang box) is where electricians install a switch, plug, or thermostat!
We splice wires in the box to carry on power (junction box), or use switch legs to turn a light on or off. You’ll learn about pigtails when splicing, and how to organize wires in an electrical box, too!
This video shows splicing wires in a single gang box:
Splice and Fold Wires Into a Switch Box
What We Cover in this Article:
- What Tools You Need for Splicing Wires
- How to Splice Wires in a Single Gang Box
- How to Fold Wires in a Single Gang Box
What Tools You Need for Splicing Wires
To splice wires in an electrical box, here’s what you’ll need!:
You may also like this roughing-in material list for electricians.
Best Wire Strippers for Electricians:
Both Klein Tools and Greenlee make the wire strippers with these yellow tips. I really like the yellow tip wire strippers because the layout of the wire sizes is awesome.
Best Lineman’s Pliers for Electricians:
View How to Buy Klein Tools Pliers
A good set of electrician pliers will make the difference when splicing.
If you buy a bad pair of pliers, splicing is harder because it’s harder to grip all the wires, and form a nice splice. Here’s my favorite Klein Tools pliers.
What is a Wire Nut (Marette):
Wire nuts screw onto splices to ensure splices are tight. They also have a metal spring inside to form a good electrical connection.
How to Splice Wires in a Single Gang Box
Before getting too far ahead, I’d first view the whole roughing-in process!
I’ll explain how to prepare for splicing wires, then we’ll cover how to splice wires!
First, make sure all wires are pulled to the box destination, and that the wires are stapled and labelled!
This is very important, because you don’t want to splice wires, only to realize you forgot to pull a wire, or you forgot to enter a wire into the box. (It happens often!)
Now, the cutting-in stage of electrical begins!
We first remove the wire jacket with an electrical knife, and then we enter the wires into the box.
It’s faster to remove the wire’s jacket first, rather than enter the wire with jacket into the box, then remove the jacket inside a small crammed area where you have to bend over all the time!
After the wires are pushed into the box, we then organize the wires.. meaning wires ARE NOT crossing over each other.
When it comes to splicing wires, it’s always best to start with your bond first for safety.. and removing the bond last if undoing a splice.
WHEN SPLICING DO THIS:
- Bond Wire (Bare Wire)
- Neutral Wire (White Wire)
- Hot Wire (Whatever color hot wire is!)
WHEN REMOVING SPLICES, DO THIS:
- Hot Wire (Typically black)
- Neutral Wire (White Wire)
- Bond Wire (Bare Wire)
This image shows the bonds are spliced first. Depending on what device will be installed in the finishing stage (plug, switch, etc), you may need to add a pigtail onto the splice (see video above).
Now, for our neutral and hot wires, after you’ve pushed the wires into the corner of the box to organize the wires, I like to use 3-4 fingers as a guide for how long to cut wires in a box for splicing.
Once the wires are cut to the same length, we use wire strippers to remove the conductor’s insulation to expose the copper of each wire. You can strip wires longer to make splicing easier!
If someone asked what I was doing on site.. I’d say, “Connecting copper to copper!”.. as you’d spend all day splicing sometimes..
Once the copper is exposed, you can then splice the wires, and we finally put a wire nut on them.
A wire nut (marette) does a couple things for our splice!
- Makes our splice tight forever!
- Makes a better connection is made (it has a metal spring inside)
DO NOT OVER TIGHTEN YOUR WIRE NUTS..
How to Fold Wires in a Single Gang Box
The final step of cutting-in wires is folding the wires into the box.
You want to push the wires into the back of the box because drywallers will damage your wire when they cut out your electrical boxes!
This is why it’s so important to not have wires cross over! If wires are crossed, pushing wires into the back of the box is hard!
A lot of DIY electrical homeowners just cram the wires into the box.. and the sad thing is, a lot of electricians do, too!
Wires are delicate.. and can cause house fires!
So if you follow my video above for how to splice a single gang electrical box, you’ll see how the wires can be tucked into the back of an electrical box no problem.
Conclusion: How to Splice a Single Gang Junction Box
A Single-Gang Box, a Junction Box, a One-Device Box.. whatever you want to call it.. that’s how you splice wires in an electrical box!
You start by removing the wire jacket, then striping insulation off individual conductors, then splicing wires together (that go together).
I hope you enjoyed the video.. Here’s all my roughing-in series videos.
