I would like to reserve/dedicate an entire slot in a single phase 120v sub-panel for lighting of a small storage area even though the total load is much less than than a standard 20amp breaker. What is the smallest breaker available and in what increments are breakers available? What is the proper breaker for say a 750kW lighting load (1.25 factor is already included for continuous use). By the way, if it matters, this panel is a sub-panel for a 3-phase 120/208 400amp panel.
Hello, First I'll assume you mean 750 watts, not 750 KW. At 120 volts, 750 watts draws 6.25 amps. A 15 amp breaker with 14 gauge wire would be acceptable or a 20 amp breaker with 12 guage wire. Don't worry about trying to size the breaker to the exact load, just don't overload a circuit. BTW, if you did mean 750KW, you'll need to find a 6250 amp breaker and that's going to cost you