How To Wire A Generator To A Breaker Box | Step-by-Step Guide

In this article, we’ll discuss the process of how to wire a generator to a breaker box.


The figure given below shows the appearance of a typical 240V breaker installed in the homes.  Here, the green one is the ground wire. Do note, when we are working on the 240V circuit breakers, then it doesn’t come with the neutral wire.

How To Wire A Generator To A Breaker Box

Materials Required to Wire a Generator to Breaker Box

For connecting the generator to the breaker box, you’ll need some essential materials which are listed below:

  • Stripping tool
  • Multimeter
  • Flathead screwdriver
  • The cable of eight by three
  • Double pole breaker having the power of 40 Amperes

If you don’t have any of the above equipment, connecting the breaker can give you a tough time. Spend some time arranging them before moving one!


Steps to connect the generator to the breaker box

Now, after making the arrangement of these necessary items, follow these steps to correctly wire the generator to the breaker box.

  1. Turn off the main power

Firstly, before connecting the generator to the breaker box then turn off the main power supply first which is coming from the power lines to the breaker box. After powering it off, verify with the help of a voltmeter. When you are completely sure, no power is coming from the power lines after turning off the main power switch for safety, then move to step 2.

2. Stripping of eight by three cable

Strip the eight by three cables in such a way that its half-inch wire end is exposed. Take the help of some good stripping tool instead of cutting it with a knife. So that you can get a cleaner cut. Strip this wire from both of its ends and make sure that only a half-inch of the wire is exposed after stripping.

3. Screw the wires

Inside the circuit breaker, we normally have two screws that are installed for holding both wires. Take two black wires and with the circuit breaker, screw them steadily. Insert the wires into the terminals and tighten the screws.

4. Fixing the breaker

The next step is to fix the breaker inside the service panel. For doing this, search the sufficient spot where you want to see your circuit in the service panel. Now insert the breaker inside the housing of the service panel at a place where you want to install the circuit.

Use the circuit’s back and forth rocking motion. Doing this would help you to place the tabbed end of the breaker first in the housing this way. Snap the rest of the breaker over the hot bus bar to finish the installation.

5. Take a look at a double pole breaker

Now you need to take a careful look at the double pole breaker. Try to confirm that it is fitted in the service panel firmly. For 240V installation, we normally use a double pole breaker that has two hot wires having 12V individually which gives us a whole 240V.

6. Complete the wiring adjustments

The ground wire now has to go through a similar bar. It must run inside the breaker box until the end of the 240-volt receptacle. Screw it securely to the end of the 240-volt receptacle after inserting the ground wire.

After doing this, insert the eight-by-three cable into the generator outlet that you want to plugin. Two screws should be there without any color. Fix these screws with two black wires. Make sure the ground wire is inserted into the green screw. So, tightly patch them so that they remain in place.

7. Attach the outlet

If the eight-by-three cable is secured, it’s time to link the outlets to the wall. Go back to your house’s main power source. Now you can turn it on. Even, with a quick push, turn your breaker box ON. Plug in this outlet with the generator and it should start.


Some suggestions for wiring generator to the breaker box

While following all these steps for wiring the generator to the breaker box, ensure that the two-line voltage cables are the same hue. This would make it easier to comply with codes.

For this mission, black and red are favorable colors. If it is required, you can also use tapes to label them. An eight-by-three cable fits well for a forty-amp breaker.

Trying to shut off breakers often isn’t the only explanation for de-energizing the main panel. Always check to ensure proper electricity termination with a voltmeter.


Final Thoughts!

Before wiring the generator to a breaker box, the first thing you can do is to find a certified electrician that can do the work for you for your safety. As it is not wise to play with high voltage wires without having any experience. 


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