samsim1
Nov 17, 2008, 01:07 PM
220 volt appliance pulling 30 amps!
Is this 30 amps per phase? 30 amps one phase? Confused:
stanfortyman
Nov 17, 2008, 01:47 PM
It's 30 amps per leg, but this is NOT equal to 60 amps.
It's 30 amps @ 240v.
Washington1
Nov 17, 2008, 02:13 PM
Lets do the math:
A two pole 30 amp breaker will be supplied by two hot bus bars. Each bus supplies 120 volts of work.
If you look at your two (or double) pole breaker, you will see two 30 amp breakers married together (basically, two single pole breakers combined to form one breaker). One of the two are making contact with one 120v bus bar. So "A" phase= 120v(30A)=3600W. The remaining 30amp breaker is doing the same, but it's being supplied by a separate bus bar. So "B" phase= 120v(30A)=3600W
Combined(30A two pole breaker] (x2) they= 30A(240V)=7200W
It's not 30(240)(2)= 14400W
It's not 60(240)
The key is to remember that it's 30 amps being supplied by two separate 120v bus bars 120 volts (2)=240volts(30)=7200 watts