Electric utilities supply residential power through two wires called "Line 1" and "Line 2," each carrying 110 to 125 volts. A neutral third wire returns current to the transformer. In the service panel, the power is divided between the two lines to serve various circuits. Balancing the power usage of a home in the service panel may require moving circuit breakers so that each line supplies a similar amount of power and neither line is overloaded.
Things You'll Need
- Battery-powered light
Survey your electrical system and determine how the existing circuit breakers are distributing the electrical loads placed on the system. Add up the power used on each circuit by the devices on that circuit. Each device has its power use listed in watts or volt-amps. Watts and volt-amps are the same. Determine which circuit breakers control the various lights and receptacles by turning off one breaker at a time to see which lights and receptacles no longer function.
Turn off the main circuit breaker in the service panel; use the battery-powered light to see. Remove the panel cover screws with a screwdriver and lift the cover off the box. Never touch the large, heavy gauge aluminum or copper wires coming from the outside, or the terminals they attach to, because the current is always present.
Look at the arrangement of the circuit breakers in the service panel. The breaker at the top left position, and the one directly below it, connect to different incoming lines. The incoming lines alternate from top to bottom and side to side. Line 1 serves the first circuit breaker on the left and the second breaker on the right. Line 2 serves the second left breaker and the first right breaker.
Count the number of 15-amp, single-switch breakers on Line 1 and on Line 2. Do the same with the 20-amp, single-switch breakers. Line 1 and Line 2 should have approximately the same number of 15 and 20-amp circuit breakers. Having exactly the same number is not necessarily correct, but in most cases the numbers should be close.
Total up the power used on each incoming line using the survey done earlier. The two lines should each have approximately the same level of power use. If there is a difference of more than 10 to 25 percent, a change may need to be made.
Move a heavily loaded circuit breaker from Line 1 or Line 2 to an empty position on the other Line. Pry the circuit breaker loose at the center, unhook it and move it to an empty position on the other line. Hook the breaker on the bar and press in at the center until it locks in place.
Tips & Warnings
- Service panels vary in configuration. The layout described here may differ from your own. Check with your service panel manufacturer for the layout of your service panel.
- If your electrical service is working and you don't have problems, this task is unnecessary and should not be done. Only do this if you are having load problems such as lights dimming slightly on more than one circuit and staying dim until other loads turn off.
- Circuits with double circuit breakers don't have to be included in the power calculations. Their loads are split between the two lines already.
- Working on your service panel exposes you to live wires and terminals. Touching these terminals can cause serious injury, burns, shocks and can possibly be fatal. Use all care, stand on a dry wooden board and wear rubber soled shoes. Pay attention and do the work when you won't be distracted by other people, pets or children.
- "Wiring Simplified, 40th Edition"; Richter, Schwan, Hartwell; 2002
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