Lighting Load on Circuit Breaker

Good evening Garage! My first post on any site but I need help. I'm working on my MEP senior design project due monday (aww yeahh). I'm trying to assign circuits to the wired lights. The panel is 120/208-3Ph. (has HVAC loading).

The formula I'm using for Amp draw is: A=Watts*Ballast Factor/(120(sq.rt(3)))

Each fixture has 2 - 32W lamps and I'm using BF-1.15 (From my prof.) and coming to 0.35 Amps/Fixture which gives me 38 on a 15Amp circuit (80% Loading). From what I've been reading 10-15 is a more normal number. What am I missing?? Thanks for the help!!

Gavin

How I do it:

A 2 lamp F32T8 ballast draws .49 amps at 120v per ballast nameplate.

12 amps(80% of 15 amp circuit)/.49=24 ballasts per circuit.

Okay cool. Thanks for the quick response! Crunchtime