What is a circuit breaker and how does it work?

A circuit breaker is one of the most important safety devices in your home. Electricity can be a potential source of fire when there is a fault, wiring problem, or equipment failure in your home, and circuit breakers work to prevent major electricity-related damage.

Circuit breakers monitor the level of electrical current, or the rate at which electrical energy flows through the wire. If the current were to get too high, the wires would overheat and potentially cause a fire.

Household electricity is defined by three characteristics:

Voltage (V)

Resistance (R)

Current (I)

  • The relationship between these features is determined by the relationship: I = V / R (Ohm’s Law)
  • Electrical power is delivered to homes at a consistent voltage (120 volts to your regular outlets, 240 volts to specialty outlets such as your dryer).
  • Resistance comes from the appliances, gadgets, and lights we plug into the system.

Because voltage and resistance are determined externally, current within your home fluctuates to meet the demands on your system. The circuit breaker interrupts the circuit whenever the current rises above a safe level.

Most conventional circuit breakers use a simple switch with either a bimetallic strip or an electromagnet. When current exceeds a safe level, the switch trips, opening the circuit so that current can no longer flow and protecting the wiring of your home.

If one of your breakers has been tripped, you can reset it by turning the breaker completely off, then completely on again. Some breakers will look like they are not tripped, but if they are not completely in the “on” position, they will not function properly.

For more information about circuit breakers or if you find you are resetting your breakers on a regular basis, call the professionals at Absolute Electrical, Heating and Air.