US NEC: 4800 watts is 40 amps at 120 volts, or 20 amps at 240 volts. This can be no more than 80% of the breaker's rated value. You need a 50 amp breaker for 120 volt operation, though 120 volt...
Watts = volts x amperes. So if your region uses 110 volts, 20 amperes is equivalent to 2200 watts; if your region uses 220 volts, 20 amperes is equivalent to 4400 watts.
Watts is the product of amps times volts. If you are asking how many watts can be put on a 15 amp circuit breaker then 15 x 120 = 1800. This will probably trip the breaker because it is close to the...