Turning Off The Power Safely

• Before installing the new 220v circuit breaker, you need to take basic safety precautions. Make sure the area around the circuit panel is completely dry and free of standing water. Put on a pair of rubber soled shoes or stand directly on a rubber mat to ground yourself. Then turn the main power to the house off. The breaker itself should be turned off too--even though it isn't installed yet--and if you are replacing an older breaker with it, you should turn it off as well.
  
  

Removing the Old Breaker

• If you are replacing an old breaker with a new 220V breaker, you can simply pop it out or unscrew it with a screwdriver. You'll noticed that it has a number of wires connected to terminal screws: most likely a pair of black or "hot" wires, but the exact type may vary depending upon your home. Test the breaker with a voltmeter to be sure it is electricity-free, then unscrew the terminal screws and free it from the wires. Be sure to remember which wire goes where. Mark one with a piece of tape if you need to.
  
  

Installing the New Breaker

• If you are installing the new circuit breaker into an entirely new position, you only need to remove the knockout tabs from the desired spot with a pair of pliers. Then strip the insulation off of the ends of the hot (black) wires and neutral (green) wires that correspond to it. Otherwise, simply proceed as you would if you were replacing an old fuse: screw the wires into their corresponding terminal screws on the new 220v circuit breaker, then pop or screw it into position. Note that 220v circuit breakers are usually double-pole breakers, which means you may need to set two positions aside for it in the box, and connect two sets of hot and neutral wires into position.
  
  

• Turn the main power on and switch the new amp to the on position as well. Then test it using a voltmeter by putting one prong against the hot terminal screw and the other prong against the ground screw (which is located on the grounding bar to the left or the right of the row of circuit breakers). Always grasp the prongs by their insulated handles, not by the naked metal on the tips. Otherwise, you may give yourself a nasty shock. The voltmeter should register that electricity is flowing as it should, which means you're all set. Screw the framing panel back in and close up the circuit box.