Providing power to Lighting Poles in Sport fields. Single phase drivers and 3 phase feeders

Cartoon1

Senior Member
Location
Florida
Occupation
Electrical Engineer
Hello all.
I'm providing power to sports lighting pole. The pole itself is compromised of 22 lights, each with a driver rated at 480V, 2.75A, 1320W single phase. I plan on running 3 phase 480V to the pole and balance the 3 phase hot runs into 22 fixtures. So each fixture will take two hot wires.

Now if we take the required circuit breaker at the panel for the feeder i end up with 1,320W X 22 = 29,0470W === 34.94 A FLA x 1.25 continuous load = 43.6A Amps so next breaker size would be 3 pole 45A.

If i do phase to phase (I Line) per IL=(I1^2+I2^2+(I1×I2))^.5 for all the individual fixtures then i end up with, since we dont have even fixtures on each phase:
  • Circuit AB (7 fixtures): 7×2.75A=19.25A ------ IA≈35.72A x 1.25 = 44.65A
  • Circuit BC (7 fixtures): 7×2.75A=19.25A ------ IB≈33.34A x1.25
  • Circuit CA (8 fixtures): 8×2.75A=22.00A ------ IC≈35.72A x 1.25 = 44.65A
Is 45A 3 pole breaker sufficient in this case and is my calculation looking at this correct? i worry about nusiance triping since these have inrush current. What would be the best breaker size in this case? I would feel safer with a 60Amp breaker.
The fixture driver is EPH-LS-16-1200L (HV Driver).

Thank you,
 
The minimum conductor size is determined by the load, and the maximum breaker size is determined by the conductors. If you want to use a 60 amp breaker, use the appropriate conductor size. I would certainly consider voltage drop, too.
 
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