Location: Install an AC Breaker

How to Install and AC Circuit Breaker

A simple do it yourself guide to replacing a blown circuit breaker in your home or office. Before we start replacing your circuit breakers, please do note that you are working with electricity. Voltage and amperage at the levels you are working with can be dangerous if you don't follow ALL THE SAFETY INSTRUCTIONS. Electricity wants to get to ground, if you give it a path, look out. So remember, be sure to follow ALL the safety guidelines (some not covered below). Electricians do this for a living do to the knowledge and risk involved. Nothing is stopping you from learning, we encourage you to do so. However, if you have any doubts hire someone to install your circuit breakers for you.

Alright, now that the legal team is happy, let's get started. To replace a circuit breaker in your home you basically need to do 4 things.
1. Turn off the power.
2. Remove the burnt Circuit Breaker.
3. Go to the store and get another one.
4. Install the new breaker.
5. Turn the power back on.
Let's go over each step in a bit more detail.

Turn off the power, Main vs Secondary Circuits

Before you start monkeying with the wires, it is a good idea to remove the power from them. This page assumes that you are replacing a breaker below the mains so that you CAN turn off the power. Most standard electric panels have a main circuit breaker at the top of the panel or load center as it is a code requirement. The breakers below this are the secondary circuits. To get started turn off the power by turning off the main circuit breaker. You can now replace any of the secondary units below it relatively safely.

Only the secondary circuits inside the breaker box are able to be replaced in a manner that removes the power from them. If you need to replace the main breaker, we suggest you call an electrician because there is no way to turn the power off. You must replace main breakers with a live circuit surrounding. The mains control the power to your system, above the mains, the circuit WILL BE LIVE. In other words, above the mains the wires are HOT if the power company has you hooked up. This image on the right shows the main circuit breakers, and the secondary circuits.

Now that we are through the safety explanation, have the power off, and know which breaker we want to replace, let's get after it. The next step is to remove the face plate of the Breaker Box or Load Center. Usually this is screwed in one or two places on the top or bottom. Once the plate is removed, the wiring and guts are exposed. There are 3 wires in each circuit, a hot, a neutral, and a ground when working with AC power. The hot wire carries in the power. The neutral wire carries the unused power out and completes the circuit. The gound wire is there to catch problems and for safety. Below you can see each in our load center. The little black or red wires going into each breaker are the hot wires. The white wires are all grouped to one side or the other (the right side below) and go back to the power company through the mains above. The ground wires are the exposed copper wires all grouped together on the left. The 2-4 very large wires in there are those that connect the power company. These are the HOT wires from the electrical meter coming into the load center. AVOID THESE THICK WIRES AT ALL COSTS, THEY ARE LIVE!!!
load center, what the wires are, and what they do


Now that we know which breaker we need to fix, what not to touch (THOSE BIG WIRES), and what each wire does, we only twist 2 screws. The screw that holds in the black (or red) wire into the breaker. And the screw that holds the breaker onto the bus bar behind it. Once you have the breaker out, go to your local hardware store and get a new one. Return, replace by turning those 2 screws "HAND TIGHT" and then put the face back on the load center.

Once the face is on the load center, make sure your new breaker is in the "OFF" position. Now go ahead and turn on the main breakers or power disconnect. Ensure everything else is working normally. Now flip on the breaker you just replaced and make sure it works right. Congratulations, you just saved yourself some money, headache, and hassle. You just replaced an AC circuit breaker!

Electrical How To and Why Guides:
Breakers and System Protection
Fuses and Electronics Protection
Which Wire Should I use
Solar Charge Controllers, What, How, and Why.
Which Battery Charger is Right?