I have a S51 400 Watt ballast. It says it current is 4.0. So this telling me that the ballast is 480Watts/120Volts=4.0 AMP Current. I needed an extentions cord that was rated at 15AMP and is 12 Gauge

Now I also have 5 2-40 Watt Flourescent fixtures in there for a total of 400 Watts.. So I am assuming that is a current of 400Watts/120volts/3.3 AMP (Am I doing this math right). The fixture has nothing on it to tell me the current.

So I am now at what 4.0 + 3.3 = 7.3 and the circuit it is on is 15AMP.
On that circuit there is also a 13inch TV, 2 Computers, 2 Monitors + plus the light fixture, + Sub boxes for the computers, a printer, etc.. I have NOT added up all their wattage.. So now I am wondering, will I blow the breaker, Is my math correct?

But I know some people are running 1000 Watt Lights in their grow room, and I have to assume there are other stuff in the room. How are they not blowing fuses. Am I tripping?

The furnance/Washer Dryer is right behind this bedroom I am using. All on their own circuit. In my laundry room there is an outlet that is tied to a 20 AMP breaker. So now I am thinking about making a hole in the back of my closet (high up) and running my extention cord to this outlet and isolating everything on this circuit (I would have to make sure its not tied to anything else). I guess that is the best thing to do.

Am I over worrried? (better safe than sorry). Arent people running 1000 Watt lamps + Fans + exhaust + Whatever else on one 15AMP circuit!
SeedKing72 Reviewed by SeedKing72 on . Electricity, Current, Overloade circuit I have a S51 400 Watt ballast. It says it current is 4.0. So this telling me that the ballast is 480Watts/120Volts=4.0 AMP Current. I needed an extentions cord that was rated at 15AMP and is 12 Gauge Now I also have 5 2-40 Watt Flourescent fixtures in there for a total of 400 Watts.. So I am assuming that is a current of 400Watts/120volts/3.3 AMP (Am I doing this math right). The fixture has nothing on it to tell me the current. So I am now at what 4.0 + 3.3 = 7.3 and the circuit it is Rating: 5