Is there anyone out there who can help me with calculating the incident energy of a motor control center? I am doing a summer internship at a corporation and am needing some help with it. If anyone out there would please help me show me how to calculate the short circuit current, power in the arc, curable burn distance, and incident energy in a cubic box of a couple of MCC @ 18 inches with the transformer info they have given me, so I can keep for reference, it would be of a great help to me.
EX. 1
padmount 3 phase transformer
capacity=3750kVA
pri volt=22860V
sec volt=480V
arc duration=0.1 sec
z=6.28%
EX. 2
padmount 3 phase transformer
capacity=3750kVA
pri volt=22860V
sec volt=4160V
arc duration=0.1 sec
z=5.68%
I have the NFPA 70E book with the equations but the problem that I am running into is that the equation for the incident energy states that it is rated for 600 volts and below. Is there another equation out there to use? Also one last question, is the short circuit current the same as the bolted fault short circuit current, if so what happens if it is not in the range of 16 to 50kA when calculating the incident energy?
EX. 1
padmount 3 phase transformer
capacity=3750kVA
pri volt=22860V
sec volt=480V
arc duration=0.1 sec
z=6.28%
EX. 2
padmount 3 phase transformer
capacity=3750kVA
pri volt=22860V
sec volt=4160V
arc duration=0.1 sec
z=5.68%
I have the NFPA 70E book with the equations but the problem that I am running into is that the equation for the incident energy states that it is rated for 600 volts and below. Is there another equation out there to use? Also one last question, is the short circuit current the same as the bolted fault short circuit current, if so what happens if it is not in the range of 16 to 50kA when calculating the incident energy?
