We are putting light bulbs on a large outside tree in a city park. We
have six 100 foot strings of 100 C-9 lights. We have two 20 amp GFI
circuits available. I plan to put 300 lights on each circuit. My math

shows 2300 watts available and C-9 bulbs use 7 watts. This comes to 2100 watts. I will use 12 guage extension cords. The light strings and bulbs are commercial grade. This all looks good on paper, but I am

worried because there is not much room for real world error. Does anybody have experience with this many lights? Wasn't there a movie about a guy causing a large scale blackout when he threw the switch on his house decorations? I don't want to be that guy. Any help you can give me would be appreciated. Thanks, Gus

shows 2300 watts available and C-9 bulbs use 7 watts. This comes to 2100 watts. I will use 12 guage extension cords. The light strings and bulbs are commercial grade. This all looks good on paper, but I am

worried because there is not much room for real world error. Does anybody have experience with this many lights? Wasn't there a movie about a guy causing a large scale blackout when he threw the switch on his house decorations? I don't want to be that guy. Any help you can give me would be appreciated. Thanks, Gus