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How do you add a 240V circuit when there is no more room in breaker panel?

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Wiki User
2007-05-23 00:04:28

First, let me say that adding another breaker on any panel

should not be done just because you can, and there is room. The

power distribution panel is rated for a particular LOAD, or AMP

maximum. This should be marked on the panel. Most residential

panels are between 60A and 200A maximum. Overloading home panels is

a very dangerous proposition as overheating, shorting or an

electrical fire can occur. The first step in adding a breaker is to

determine the full amp load of the panel at this time. There are

tables that can help you to determine this but they do get a little

complicated. They include finding Full Load Amp values for all of

the equipment now on all of the circuits within the panel. Then you

can start adding, de-ratting and averaging depending on the tables

that you use. There are assumed load values for all outlets not

used at this time, a total percentage of the conductor sizing that

must be taken into account and various other steps. Your local

electrical contractor can help you with the calcs or the whole

process. Once you determine that another circuit can be added you

can add a circuit that feeds a SUB-PANEL in which there is room for

additional circuit breakers. In most full panels this will require

removing two or more circuits and adding in its place a circuit to

feed the sub-panel. If you do not want to get an electrician then

at least get the help of a really good how to book on electrical

how to. Your local home remodeling and repair supplier can usually

help with this. As Always get the approval of your local

jurisdiction or building official and get any required permits. On

a scale of 1 to 5, I would rate this project at a 4 1/2 just

because of the technical knowledge required to do the calcs. The

actual work is relatively easy, about a 2 1/2 to 3 a good weekend

project for an experienced home owner. Hope this helps ALWAYS


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