How to Understand an Electric Panel

Every homeowner will experience opening up the electric panel to repair or examine the circuit breakers. If you are not familiar with the components of a circuit breaker, simply trying to fix an issue may become a costly mistake you cannot afford to make.

Supply List

• Screwdriver

1. Open the door of your circuit breaker to expose the two-pole circuit breaker, which has two rows of breakers located directly across from one another.


2. Locate your main breaker by finding the largest of all the switches. Usually, you can find it at the top or bottom of the box. It should read 100 A or 200 A beside it. When you turn this switch to the off position, it causes every circuit in your home to turn off, resulting in all of the electricity being shut off.


3. Notice the setup of the circuits in your home. There should be a labeled diagram on the inside of the box, which depicts the location of your house that the breaker is linked with.


4. Examine the outside of your breaker box for a smaller box. Larger homes may have a second box or a subpanel that connects to the main circuit breaker.


5. Look at each circuit. "On" and "off" options should be associated with each switch. When you turn the switch to the off position, you are killing power to the particular area of your home the circuit represents.


6. Observe the number and letter combination on each switch. It probably contains a two-digit number, such as 15 or 30 and the letter "a." This signifies the number of amps that the circuit breaker can handle. When you add up the total number of all of these amounts, it results in the total number of amps currently used. If you subtract this number from total amount of amps your main breaker has, you get the amount of remaining amperage.


7. Unscrew the four screws holding the front of the panel to the inner components of the unit; this will expose the wiring of the device. Be careful, each one of these wires is carrying electricity through it. You should notice a thick wire running down the middle of the panel's guts called the "bus bar." The bus bar is hot whenever the main breaker you have the main breaker turned on. The bus bar is how each breaker connects together.


8. Find the "neutral bar," a narrow bar filled with white wires and small screws. This is where current travels back through the panel and out through a larger white wire that conducts it back to the transformer.