The amp level of a circuit breaker refers to "amperage," which measures the strength of the electrical current flowing through it. A 30 amp breaker can handle a stronger current than a 20 amp breaker, which can handle more than a 15 amp breaker and so on. Which one works best for you depends on the specific wiring of your home. But like any other kind of breaker, a 30 amp breaker is very simple to install. You can do it yourself in just a few minutes, provided you take a few common-sense precautions.
Put on a set of rubber-soled shoes, or place a rubber mat directly in front of the circuit breaker. Wipe up any water or wet patches before you start. Make sure you stand on the rubber at all times when you are installing the breaker.
Shut off the power to both the main switch and to the breaker you intend to replace. Then detach the metal frame surrounding the row of breakers by using a screwdriver.
Set a multimeter to "Volts AC." Touch one end to the terminal screw of the old breaker. Touch the other end to the grounding screw--usually set in a vertical bar on the far end of the circuit box. The multimeter shouldn't show any electricity flowing through the breaker.
Pop the existing circuit breaker free from its position, or unscrew it if it is an older model. Disconnect the black "hot" wire or wires from the terminal screws, taking care to note which one goes where (mark one with a piece of masking tape of you are worried about becoming confused).
Fit the wires into the same position on the new 30 amp circuit breaker, then tighten the terminal screws until they hold the wires firmly.
Place the new 30 amp breaker into the vacant spot on the breaker panel. Then pop it into place or screw it in as appropriate.
Turn on the electricity, first with the main switch and then by switching the new 30 amp circuit breaker to the "on" position.
Apply the multimeter to the new circuit breaker to confirm that electricity is flowing through it normally. Then place the metal frame back into its accustomed position and tighten its screws into place.
Installing an entirely new breaker differs little from replacing an old one. Simply knock out one of the free tabs on the circuit box, and strip about 1/2 inch of insulation from the black "hot" wire and the green ground wire. These steps replace Steps 3 and 4 in the instructions. You can then place the new breaker in place as normal.
A new circuit breaker should always match the amperage of the breaker it is replacing. Don't use a 30 amp breaker to replace anything but another 30 amp breaker.