How to Measure Wattage on a 2-Pole Breaker

Turn off the appliance or electrical device that is on the wiring circuit for the breaker you are testing. For example, if you are testing the breaker for your clothes dryer, turn it off or unplug it from the electrical receptacle.

Open the door to your breaker box.

Observe the circuit breaker guide on the inside of the breaker box door to determine which breaker to test. The guide should have an area written on it to correspond to the breaker location in the box. For this example, it should read dryer or laundry room.

Count the number of breakers from the top down on the left or right side of the breakers to find the correct one to test. This is the same position as the guide on the breaker box door. The 2-pole breaker will occupy two slots in the breaker box but will have one handle to switch it on or off.

Turn a multimeter on and turn the center dial to "AC" for alternating current and amps to "X100" for the highest setting. Plug the red test lead into the "+" jack on the meter and the black test lead into the "-" jack on the meter.

Place the red test probe end on one of the metal tabs on the left side of the circuit breaker. Place the black test probe end on one of the metal tabs on the right side of the breaker. Read the digital display of amps. Write this number down on paper with a pen.

Turn the multimeter dial to "Volts" and retest the circuit breaker as you did for amps. Write the voltage down.

Multiply the amperage times the voltage to obtain the wattage this circuit uses. For example, 10 amps x 240 volts equals an appliance that uses 2,400 watts.