Xtatico, You are correct. But saying that the breaker is sized in consideration of the load only is also an incomplete statement. If the breaker amperage exceeds the current carrying capacity of the wire the wire could overheat and burn. So, I will still modify my statement.
As we know all electrical devices run on magic smoke. If the magic smoke escapes bad things happen. Unless someone is able to adhere to the magic smoke containment codes, ABYC electrical wiring standards in this instance, magic smoke could escape and rain down bad Juju. Therefore, HIRE AN ELECTRICIAN.