Connecting 8 gauge electrical wire in junction box: how to (ANSWERED!)

A junction box is needed to safely make a 8 gauge wire connection. This makes sure that everything is properly connected.

8 gauge wires are often used for radios, mounting switches, receptacles, and light fixtures.

 An 8-gauge wire is thinner than a 6-gauge wire. An 8-gauge wire has a diameter of 3.264 mm. Its cross-section is 8.37 mm2. An 8-gauge wire’s ampacity at a median 75 °C temperature is 50 amps. 

Definition of an electrical wire gauge

The measurement and ampacity of a wire indicate the amount of current that can pass through it without causing any damage. Therefore, a wire gauge is a reference to a wire’s capacity to carry current and its physical size. 

The number that is designated to it is reversely proportional to the conductors’ diameter. To put it simply, a smaller wire gauge number has a larger diameter. For instance, an 8-gauge wire is 26.1% thinner than a 6-gauge wire. The diameter of a 6-gauge wire is 0.1620 inches, whereas the diameter of an 8-gauge wire is 0.1285 inches. A wire’s weight per unit length and resistance also depends on the rank of the gauge.

Why is a wire gauge important?

The wire size or gauge of a cable is the measurement of the conductor’s thickness carrying the electron flow. The conductor also aids in smoother transition by suppressing resistance. 

When you know the gauge of a wire, it helps you decide faster if it is suitable for a particular application.

A gauge assists homeowners as well as industry professionals to know how much current the solid cable can carry. The cross-sectional zone of the wire is used for doing so. 

The gauge is selected based on the needs of a room and the local code.

What is the difference between 8-AWG and 8-Gauge?

There is no difference between 8-AWG and 8-Gauge. AWG does not assess a conductor’s insulation. A smaller conductor has a higher AWG measurement or number. ‘Gauge’ is just the term used in writing for a better understanding. 

An 8-gauge wire is a standard size and is commonly used in commercial and household wiring. Though it has lesser demand than a 6-gauge or a 10-gauge wire. But you might choose an 8-gauge wire depending on the purpose you want it to serve and the amount of current it can carry.

Do you want to learn how to connect 8 gauge wires in an electrical junction box? Use the steps given below to have safe wiring connections.

Tools you will need to connect 8 gauge wire:

  • 3/4-inch clamp connectors (2)
  • 4-inch square cover
  • 4-inch square metal junction box
  • 10-gauge bare copper wire
  • Blue wire connectors
  • Hammer
  • Non-contact voltage tester
  • Phillips or slotted screwdriver
  • Pliers
  • Pocket knife
  • Utility knife

Steps of connecting 8-Gauge electrical wire in Junction Box:

1st Step

Check where you are going to install the junction box. This shouldn’t be too close to wet spots. Check your local code to see the requirements. Turn off the electricity and wear protective equipment.

Mark where you are going to install the junction box with a pencil. You can pre-drill a hole in the wall to make things easier.

Take the 4-inch square junction box and place the screwdriver against the 3/4th inch knockout on its side. Now remove the knockout by hitting the screwdriver with the hammer. If you are not fully successful, use the pliers to hold the knockout. Twist it to take the knot out of the box. Remove the knockout on the other side of the box in a similar way.

2nd Step

Now through the knockouts, affix the 3/4th inch clamp connectors to the junction box. Screw the connectors’ locknuts to the threads. This will fasten the clamps properly to the box. 

3rd Step

Take the help of the non-contact voltage tester to ensure that there is no power in the wire. Now through the clamp connectors, push the 8-gauge wire inside the junction box. In regular wiring, an electrical circuit with an 8-gauge wire will have 3 to 4 wires.

4th Step

Next, use the wire stripper to cut off the electric cables’ exterior black sheath. This will reveal the interior 8-gauge wires. If the wire is too big for your wire stripper or cutter, use a pocket knife to remove 3/4th inch from the wire’s insulation. 

5th Step

Now we can push the wires inside the junction box and connect them with each other.

7th Step

The junction box has the pigtail ground wire (bare copper) affixed to it. Additionally, there are also two bare copper wires. Follow the instructions that come with your junction box so that you connect the right wires together.

You have to connect the 2 8-gauge wires which are white, to the blue wire connector inside the junction box. You need to twist them to join them or you can use a wire connector.

8th Step

You have to make sure that the junction box can hold the NM cable steadily. For this, you have to screw the clamp connectors tightly. After putting the wires inside the junction box, use a square cover to close it.

These are the steps that tell you how to start connecting an 8-gauge wire. The most important point to remember is not to twist the 2 white 8-gauge wires that are there in the junction box. Any connection that you made must be secured. Check with an electrician or an inspector before you turn the electricity back on. You should also check your local code before you start.

We have discussed how to lengthen an electrical cable here.