I'm in the process of wiring a new shop (30 x 40') I built last year. I had an electrician put in the disconnect near the meter and install the buried line and put in a Square D QO 100 amp breaker box. I'm comfortable taking over from there. I've put in approx 20 outlets ( the 20 amp kind ) using 12 guage romex on three 20 amp circuits: No problems.
I then used 12g romex from the breaker box to a switch box and put in two 3 way switches and ran 12/3 romex for the travelers to another switch box. From there I wired 8 light fixture round boxes and began putting in 500 watt halogen light fixtures one at a time and tested by throwing the switch after each one.
I put up 4 fixtures one day and came back another to continue and as I thru the switch the 15 amp circuit breaker tripped. I started taking them down one by one to troubleshoot ... I finally figured out that there was no short, I was overloading the circuit and turning on the switch in colder weather was tripping the circuit. I was surprized. I assumed a 15 amp circuit breaker was plenty for as many lights as I chose to put in.
My goal is six 500 watt halogen fixtures with two 300 watt halogens over a long work bench on one switch. The panel has 12 slots so that's no problem. If I need lights on, I'll always have them all on. Watts = volts x amps right ? So 3600 watts divided by 110 volts = 32.7 amps . Can I just buy a 40 amp circuit breaker and wire it the way I intended ? Some how that seems like a lot of amperage just for a light circuit doesn't it ?
BTW, the other switch was intended for outdoor lighting but can be used to divide the indoor lights. Also, all of the romex was 12 guage.
Reply With Quote
