When choosing an electrical panel box cover, consider both the size of the box, its type and its contents. The panel box cover should be made of steel and large enough to hold the necessary circuit breakers. Bigger box covers are available if a sub-panel of circuit breakers is installed.
There are four main types of electrical panels. Main breaker panels contain a master breaker that is able to turn off the power to the entire house and determines how many amps the panel can withstand. They are usually located no more than 10 feet from the electrical meter and feeder cable.
Main lug panels substitute the main breaker with wires that attach to lugs. Main lug panels often have a separate disconnect switch. These are usually located at the electrical meter so the power can be turned off from outside the house in the event of an emergency.
Sub-panels redistribute energy to accommodate usage patterns. They are often installed when an existing breaker panel does not contain enough empty slots to add needed circuits. Multiple sub-panels can be installed on the same breaker, and these are limited only by the circuits available on the said breaker.
Transfer switches are like sub-panels, but instead of redistributing energy, they take power from a portable generator and convert it to electrical power. These are helpful in areas prone to storms that may knock out the electricity. Transfer switches come in two types: Automatic switches allow the transfer switch to run at all times, while manual switches need the user to start the generator and switch to the back-up system each time the power goes out.