How much electricity your home can use is closely correlated to how many appliances can be used simultaneously. If your electrical service is only 60 amps, you will need more power to run a hair dryer, electric water heater, and stove simultaneously. However, you can use numerous appliances at once with a 200-amp service.
You must determine which of the major components of your home’s electrical distribution system—such as the wire, the conduit, the meter, the panel, and the main breaker—has the lowest amperage rating to determine the appropriate size of your electrical service. Its rating applies to the entire electric service provided to your home.
- Measure the pipe’s or conduit’s width where the main service wire is located. If you have above-ground service, the conduit is a pipe that enters your home from the main electric wire suspended from a pole. If you have underground service, the conduit enters your home from the main wire buried in the ground. One-inch conduits can accommodate wires for 60-amp services, whereas one-and-a-quarter-inch conduits can accommodate wires for 100-amp services. A 60-amp service could enter your home through a conduit that is only two inches in diameter because so many conduits are large.
- If you can, measure the principal service wire’s gauge. Six-gauge copper wire has a carrying capacity of 60 amps, four-gauge wire of 100 amps, two-gauge wire of 125 amps, one-gauge wire of 150 amps, and 2/0 copper wire of 200 amps. The wire is larger when the gauge is lower.
- Verify the electric meter to see if it has an amperage rating. It may be printed on the front or a label affixed to the body.
- Look to determine if your electrical panel’s label specifies the maximum number of amps it can withstand. The label may have been added by the panel manufacturer, an inspector, or both during your panel installation or a subsequent inspection.
- Check the amperage rating of the primary breaker or fuse on your electrical service panel, which may or may not be located near the other breakers and fuses there. The biggest breakers you have are typically the important ones. It should specify how much it can contain on it or right next to it.
- Find the lowest rating by comparing the three. The lowest number represents the electrical service capacity of your home.
