How to Determine the Amperage of a Circuit Breaker

It is important to know the amperage of a circuit breaker so you don't overload the breaker with too many appliances. An overloaded circuit causes heat to build in the fuse box, which melts the wiring's plastic insulation. When insulation melts, current is no longer contained and an electrical fire may result. When in doubt about your electrical capacity, determine the amperage of your circuit breaker and don't overload the circuits.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Calculator

1. Look for the data plate attached to the circuit breaker you want to determine the amperage of. The electrical capacity of the breaker is labeled FLA or LRA. If the capacity of the breaker is expressed in amps, then you have your answer. However, sometimes capacity is expressed in watts.

2. Pull out your calculator to determine the amperage in watts.

3. Perform the following calculation if the electrical capacity is expressed in watts to determine the amperage of the circuit: Divide the wattage by the voltage of the circuit. In the United States the voltage is usually 120 or 240. The resulting number is the amperage of the circuit breaker.

Tips & Warnings

• If you have too many things needing electricity than is safe for one circuit, use an extension cord and plug some of the items into another outlet that is connected to another circuit.
• Make sure any extension cord you use is designed to carry the amount of current needed to power the items to be plugged into it.