The Main Electric Panelboards: The 220 Volt and 110 Volt

One of the most intimidating home projects definitely entails electrical wiring. And if you are talking about electrical stuff in your home, then you are unquestionably going to have to deal with the main breaker panelboard. The following article will provide a brief synopsis of the main breaker panelboard.

Electrical panelboards: Safety First!

Electrical work is not always complicated, but it can be very dangerous. In fact some municipalities require you be an electrician to perform any electrical work, including working on an electrical panelboard ? even if it’s in your home. Furthermore, your township will almost always require a permit to be had to complete any significant electric work beyond easy tasks like replacing receptacles. It is never advisable to perform a task that you are not qualified or knowledgeable to perform.

Electric Panelboards: Let’s Talk Volts and Amps

Almost all homes in the United States have wired panelboards with 100-200 amps at 220-voltage service. For homes equipped with natural gas, propane, or oil heat, panelboards with 150 amps at 220 voltage is usually enough to meet electric demands throughout the year.

For homes with a completely electric heating system, 200 amps is the minimum recommended service level. If a house has a heated pool or spa, electric radiant floor heat, or other “device” that needs a lot of energy, 250 amps or more is recommended.

Electric Panelboards: 220 Volt and Service Entrance Lines

Two hundred and twenty volt service is provided by two service entrance lines, each of which carries 110 volts to ground. The service lines are out of phase with each other, which is how you get 220 volts of total potential across the two wires.

These two service wires come into the panelboards along with a ground wire. The service lines connect to a main breaker panelboard that controls the entire house and ensures the house doesn’t overdraw current from the outside transformer.

From the main breaker panelboard, each of the two service lines connects to one of the power buses on the back of the breaker panelboard.

Electric Panelboards: Service Entrance Lines and circuit breakers

If you go down the panelboard vertically, the service line that powers the slot alternates. Panelboards are mostly numbered with odd numbers down the left and even numbers down the right side. So this mean that breakers 1 and 3 are powered by different source lines, while breakers 1 and 5 are powered by the same line.

This is purposely done. If you look at your panelboard, you’ll notice that there are some ‘double-size’ breakers in most panelboards. These breakers are 220-volt breakers that usually power big appliances (i.e. stove or furnace). And since they sit across both lines, they are able to provide 220 volts of potential to an appliance.

Important: don’t confuse the ‘double-size’ breakers with the smaller ‘tandem breakers’ which can control more than one circuit but can only provide 110 volts of service because they are only connected to one service entrance line.