How to Make A Safe Wire Connection

Make tight electrical connections with the right wire connectors and at outlets.

By Jeff Gorton

From The Family Handyman

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Make Safe, Strong Connections

About This Project

If wires come loose, you could get arcing and overheating, which could lead to a fire. However, thanks to reliable connectors and terminals, it’s fairly easy to make safe, strong connections. But there are a few things you have to watch out for. We’ll show you how to pick the right connector for the job and how to prepare the wires for the best connection. We’ll also show you why you should spend a little extra money when it comes time to buy outlets and other electrical devices. With careful attention to detail, you can rest easy knowing your wiring job is as safe as you could possibly make it.

Wire Connectors

Every wire connector is made to join a certain minimum and maximum volume of wires: The larger the wire gauge, the fewer it can hold. Always check the approved list on the packaging to make sure the connector is listed for the wire combination you want to join. Even though the connectors appear to be color coded, you can’t rely on this. For example, one style of yellow connector joins up to four 14-gauge wires, while another connects a maximum of three. You have to check the label on the package or go to the manufacturer’s Web site to find out. Keep a range of small to large connectors and their packaging on hand so you won’t be tempted to make do with the wrong size.

Start by stripping the ends of the wires. Check the label on the connector package for the length of bare wire to expose. For all but the smallest and largest connectors, this is usually about 1/2 to 5/8 in. Then arrange the wires parallel to each other with their ends aligned. Keep your eye on the wire ends until the connector covers them to make sure none slips out of position. You don’t have to twist the wires together before you screw on the connector. Simply twist the connector until the insulated wires outside the connector begin to twist. When you’re done, tug on each wire to make sure they’re all firmly connected.

Buy a Wire-Stripping Tool
Wire-stripping tools do a fast, clean job without nicking and weakening the wires. For most standard house wiring requiring 12-gauge and 14-gauge plastic sheathed cable, I like the Klein No. 1412 stripper ($18) shown here. It can cut the plastic sheathing of 12-2 and 14-2 plastic sheathed cable, as well as strip insulation on individual wires.

Extend Stranded Wire 1/8 in. Beyond Solid Wire
If you hold the ends of solid and stranded wire even with each other while you screw on the connector, the stranded wire will often wrap loosely around the solid wires, resulting in a loose connection. This is especially likely when you’re joining multiple solid wires to one stranded wire. The problem is easy to prevent by extending the ends of all stranded wires about 1/8 in. beyond the solid wires. Then install the connector as usual.

TIP
Stranded wire is a little larger than the same gauge of solid wire. Use a wire stripper labeled for stranded wire, or use the hole for the next largest gauge of solid wire. Remember to tug on each wire to make sure the connector has a solid grip.

TIP
If cutting a wire leaves it too short to work with easily, splice on an additional 6-in. length with a wire connector.