Wiring the Breaker

• Before beginning the project, it is helpful to understand a few basic concepts of electricity and electrical wiring. If you think of electrical current as water, the amperage is how much water flows over a dam in a given time period. The voltage is equivalent to the force of the current, determined by the height of the dam. Together, amps and volts determine a circuit's power or wattage. Electric current comes into a house in two 120-volt lines (older homes had 110-volt lines, hence the 220/240 designation) and one neutral line. These wires go into the home's breaker box and each connects to a separate bus bar. Normal household circuits run with 120 volts at 15. Appliance-heavy circuits like those found in kitchens will have 20 amps. Heavy-duty 240-volt circuits connect to both hot bus bars through a breaker rated between 30 and 60 amps. Different appliances require different amperage amounts.
  Make sure your box can accept another 220/240-volt circuit before doing any wiring. There must be two adjacent unused circuit-breaker spaces, as heavy-duty breakers are twice as wide as normal breakers. If there are no slots available, an electrician should be able to install a larger panel or a subpanel. Turn off the power to the service panel at the main breaker. Make sure you have a flashlight handy because this will kill all electricity to your home. Remove the covers from the empty spaces in the service panel where you will be adding your new breaker by popping them out with your screwdriver.
  Make the wiring connections. Connect the two hot wires (one black and one red) from the 220/240-volt circuit to your two-pole breaker. The white neutral line should be connected to the neutral bus bar. Snap the breaker into place in the empty space in the panel. The breaker will connect with the bus bars, closing the circuit. Turn on the power to the circuit breaker box.