Max Electric

How to Install a Circuit Breaker

Circuit breaker protect electrical circuits from overloading, short circuits, and various electrical hazards. Proper installation of circuit breakers is important to ensure the safety and consistency of electrical systems. This blog sheds light on installing a new circuit breaker in an electrical panel, from selecting the right breaker to wiring it correctly and safely. Read the blog for a complete guide on circuit breaker working and types. Take proper precautions while installing circuit breakers, including following all safety strategies and using accurate equipment and techniques. It is best to take a professional’s advice on how to install a circuit breaker. 

1) Choose the right circuit breaker

The initial step in installing a circuit breaker is to choose the right breaker for the electrical system. Circuit breakers are of different sizes, types, and amperages. Thus, selecting one that suits the voltage and amperage of the electrical system and the load it will be carrying is important.

  1. Determine the amperage and voltage of the system. This info can be found on the main electrical panel or in the electrical specifications of the appliances and devices.
  2. Once the amperage and voltage of the system are determined then calculate the maximum amperage of the circuit breaker. Add up all the amperage ratings of all the devices and appliances connected to the circuit, and after that add a safety margin of 20% to ensure that the circuit does not overload. For eg, for installing a circuit breaker for a room with 20 amps of electrical load, choose a breaker with a rating of at least 24 amps.
  3. For residential electrical circuits, 15-amp breakers are used for lighting circuits, receptacle circuits in bedrooms, and other low-power circuits. These circuits usually carry a maximum load of 1,800 watts which is sufficient for most plug-in devices like televisions, computers, and small kitchen appliances. Whereas 20-amp breakers are used for circuits that power larger appliances, like refrigerators, air conditioners, and power tools. It also includes kitchen countertop receptacle circuits, bathroom receptacle circuits, and other circuits that expect heavier loads. These circuits usually carry a maximum load of 2,400 watts.

2) Turn off the power

The circuit breaker panel, also popular as an electrical panel or breaker box, naturally looks like a metal box mounted on a wall in a utility room and a garage. The panel generally has a hinged door protecting the circuit breakers inside. 

Before installing a circuit breaker, you must turn off the power to the electrical panel and the circuit breaker being worked on. Switch off the main power switch or the main circuit breaker that delivers power to the panel. The main breaker receives power from the utility company and diverts it to individual circuits that power several household devices. These devices include lights, appliances, and outlets. If the main breaker is on the circuit panel, it is typically positioned at the top or bottom of the panel. It is positioned next to the electricity meters if it is not on the circuit panel.

3) Remove the panel cover

Usually, the panel door is on one side and secured with a handle or lock on the other side. In a few cases, the panel cover needs to be removed by unscrewing the screws that hold it in place. Ensure not to touch any wires or terminals inside the panel because they can still carry an electrical charge. Use a torchlight to inspect the wiring and locate where to install the circuit breaker by classifying blank areas.

4) Install the circuit breaker

Remove one of the knockouts (the small sections on the box that allow for the installation of electrical wiring) on the panel cover to install the circuit breaker and pull out the breaker into the panel box. When it is installed, wire the circuit breaker by connecting the wires to the terminals with the help of a screwdriver or pliers. The circuit breaker wiring connects the black or red wire to the breaker’s hot terminal, the white wire to the neutral bus bar, and the green also looks like bare wire to the ground bus bar. Tighten the screws properly but not too tight, as this can damage the wires.

5) Test the circuit breaker

After the circuit breaker is installed and wired, test it to ensure it is installed and working properly and safely. To see this, turn on the power to the panel and the circuit, and test the voltage with a multimeter. The voltage of a specific circuit will depend on the load and the system’s design. If the voltage is correct, test the circuit by plugging in a device or turning on a light connected to the circuit. If the device works well and the breaker doesn’t trip then Congratulations!!! The circuit is safe and ready to use. If the device does not work or the breaker keeps tripping then there may be a wiring problem or a faulty breaker that must be checked by a licensed electrician. 


Improper circuit breaker installation can eventually lead to short circuits and sometimes fire or other damage to your property. That’s why a professional electrician should always be considered to repair or install the circuit breaker for you. Professional electricians are experts in electrical safety and repair. They are skilled and trained to identify and fix electrical problems efficiently, minimizing possible dangers. They also follow the electrical codes and regulations, ensuring that all work is compliant and safe.