2X4 lay ins

[aelectricalman]

Ive got a lot of 2X4 layins rated at .80A. They have to be connected to a 20A circuit. Each of the 4 lamps per fixture is 40W and im going to be leaving them on for over 3 hours. Does anyone know where I might find the information that helps me determine how many fixtures I can put on this circuit? I dont want to know the answer, just a little more direction. I know ohms law and I know how to calculate load, but im stumped with the 3 hours. Thanks a million!

 

[HEYDOG]

I would look at 210.19(a)(1) 210.20(a) 220.18(b) and in article 100 under definition of a continous load.

 

[augie47]

Look at the definitions for Continuous and then look at 210.20(A) and see if the helps.

 

[aelectricalman]

im an idiot. I figured it out . Thanks.

 

[augie47]

far from being an idiot and your approach of wanting direction instead of answers is admirable.

 

[LarryFine]

im an idiot. I figured it out .

On the contrary!

 

[aelectricalman]

On the contrary!

I had a momentary lapse in brain waves. If the question had just said continuos load, I would have easily figured it out but noooooooooooooooo, it had to make me think. Just Kidding. Thanks for help.

 

[Ragin Cajun]

Forget about using the lamp wattage. Use the line amps from the label on the ballasts to calculate fixture VA (volts * amps) and go from there. (Don't ever use watts!)

RC

 

[barclayd]

One other thing you might consider. Whatever your calculation reveals, let's say 20 luminaires, I don't think it is a good idea to put them all on one circuit. Splitting them up on two circuits gives you the necessary capacity to add additional lujinaires in the future.
Also, various energy codes restrict the overall Watts/Square Foot you are allowed.
good luck
db