Load sums for low & soaring voltage circuit? To my understanding that a commercial circuit breaker have 20 amp load...
To my understanding that a commercial circuit breaker have 20 amp load or approx 2200w nouns. I have a circuit breaker i.e. shared both 110V light fixtures and 12v frothy fixtures
One (1) flourescent fixture with 4 x 32w bulbs = 128w
One (1) 110v tracklight near 3 x 50w halogen bulbs = 150w
Three (3) 12v tracklight with 4 x 20w halogen bulbs = 240w
Total watt is 518w which is below the wattage restraint.
But by the equation Watt / Volt = Amp,
The total AMP load for the three 12v tracklights next to 12 halogen bulbs: 12 * (20w / 12v) = 20 amp
I know there is something wrong here that does not tag on up. Please help. I am planning to affix one more 110v tracklight fixture next to 3 x 50w halogen bulbs if it is possible.
thanks
Answers: You've neglected one article: At some point (after the 20A breaker) the 110V goes through a step down transformer to bring it to 12V.
Yes, your 12V lights are drawing 20A (at 12V) but the draw bad the 110V circuit is approx 2.6A (assuming your transformer is running 80% efficient).
First, household wiring is 120 volts not 110. Your 20 amp breaker provides 2400 watts. Your flouresent fixture have a ballast that steps up the voltage. Figure around 90 watts for that fixture. The 12 volt lighting is provided by a step down transformer from the 120 volt circuit. You are using just over 2 amps for the low voltage lamp. You were close until you get to the low voltage lamps. You be correct with the 240 watts. But you want to divide that by 120, not 12. So your circuit is around 480 watts or 4 amps. The new fixture would help yourself to another 150 watts or 1.25 amps. So your load would be in recent times over 5 amps on a 20 amp circuit. No problem at all.