Whether or not to change out the breaker box is a question many homeowners have faced. Age, period built, brand, maintenance, environment, and cost are just some of the factors to consider when making this decision. There are a few options for any upgrade, but it really comes down to the needs of the individual breaker box.
In order to understand the needs for a service change, there are a few items within the service that need to be defined. An electrical service generally includes four major parts: the weatherhead with associated wire (which may be underground), the meter base and enclosure, the service feeder to the breaker box, and the breaker box itself.
The weatherhead is where the utility connects to your service. The associated wiring and conduit is generally governed by the utility, even though the homeowner is normally responsible for its parts and installation. The meter base is where the meter is inserted. The meter is owned by the utility, and the enclosure may be locked on or off by the utility.
The wiring from the meter base to the electrical panel is called the service feeder. There may be some installations where the meter base and the breaker panel box are the same. In this case there is no feeder.
Finally there is the breaker box. This houses all the breakers and sometimes in older installations it houses fuses as well. The size of box is usually measured in Amps, for example 100A, 125A, and 200A. This is the capacity of the service.
A general rule of thumb for when should you upgrade your breaker box is if two of the four components need to be changed, the entire service should be upgraded. The requirements of what needs to be changed are stipulated by the local authority having jurisdiction, usually the inspector.
If the service is being sized up in capacity, such as from 100A to 200A, the entire service must be changed out. Once the service is changed out, the serving utility may require that the meter base be moved. It is most commonly moved to the front or side of the house, normally no further than 10 feet from the front.
When considering the size of service, a few factors should be considered. Services in the 100A and 125A range are found in houses under 1000 square feet or are used for large appliances that are served by gas. As the load increases it is more common to find a 200A service or more. To evaluate whether your service is too small for the building, consult a qualified licensed electrician.
When selecting a new panel there are many options to choose from. A main breaker panel is almost always suggested or required. Beyond that, it is recommended that you use a panel manufacturer that has easily obtained, affordable parts, such as breakers and other replacement parts. It is also suggested to leave enough space for future expansion. Cost, versatility, and availability will usually indicate a 200A service if the entire service is being changed out. There are conditions where a larger service will be required or needed.
Just as it is advisable to consult a licensed plumber to evaluate the sewage and water lines in a building, a qualified licensed electrician is also highly recommended to inspect any electrical service. An electrician is the best source for information when any breaker box is in need of replacement or repair.
Information Source: http://nwrenovation.com/home-care/should-you-upgrade-your-breaker-box/