120/208 to 277/480 distribution

[mstrlucky74]

I often review a bid set of drawings where someone in the company will say ....well they distribution for the bigger loads/equipment is 120/208v we can just Value engineer it to be 277/480 then step it back down near the equipment/panels. This sounds good and makes sense but then why did the engineer design as such?

what factors do you need to consider before jumping to the conclusion that the 120/208 feeds can be 277/480?

hope this makes sense.

 

[infinity]

I often review a bid set of drawings where someone in the company will say ....well they distribution for the bigger loads/equipment is 120/208v we can just Value engineer it to be 277/480 then step it back down near the equipment/panels. This sounds good and makes sense but then why did the engineer design as such?

what factors do you need to consider before jumping to the conclusion that the 120/208 feeds can be 277/480?

hope this makes sense.

There are several factors starting with can the POCO provide 480Y/277? Also there is a point where is makes sense to go with the higher voltage and then step down for 208Y/120 volts. Someone once told me that the point was 500 kva or higher load to go with the 480Y/277 volt system maybe an engineer can confirm if such a number exists.