Re: Ampacity of main distribution panel
Guys please be patient with me, sorry for my confusion, but please dont look at 30kVa/(1.732*380) = 45.58Amps.
Each 10kVa load require 220V. What I mean is, I should utilize the 220V Line-Ground of 480V-380V(LL)/220V(LG) system, what current will I get and if I use 220V Line-Line of 480V-220(LL)/127V(LG) system, what current will I get?
Now, please tell me what OCPD rating should I select for both?
Actually, it is a very hot discussion with our subcontractor who made the calculation. He arrived at the calculation wherein each phase AN, BN, CN current is 45.58Amps, using 220V line-ground of 480V-380Y/220V. Then he multiply 45.58Amps by 1.732 to size the main OCPD. Should I allow him to do this way? I think 1.732 is not necessary in the calculation since phase current is also the line current here, 45.58Amps is enough reference in the selection of OCPD.
Your replies, charlie b and jtester are very very much appreciated.