[bickyd]

Loads only use what they are designed for , 1500 watts divided by 120 volts equals 12.5 amps. On a 15 amp breaker , this is fine. On a 20 amp breaker this is fine. You will not be able to plug into a 30 amp circuit or higher due to plug configuration. As previously stated , the breakers protect the conductors. you can have 12 receptacles to a circuit. you can plug 24 appliances into this circuit but it will throw the breaker instantly when you turn them on, thus protecting the conductors and building they are in. Breakers are rated for 10000 amps symmetrically and work best when the rise of amperage is FAST. Adding more grounds or a heavier ground to a service only slows down the rise of a fault because the fault current has more paths to travel thus limiting the fault current to rise symmetrically. all services are protected by number 6 copper now so in a large fault condition, it burns through and allows the fault current to travel on the neutral back to the distribution cutout or main , depending on where the fault is. On a side note, I have often wondered about the cold flow properties of aluminum when used in cases of porsche motors, but that is another topic entirely. hope this helped.
Dan.