FEEDING 400aASECTION

[Toros]

HI,
WHY SOME ENGINEERS FEED THE 400A METER SECTION BY @500 MCM, THHN,CU @ 75DEG @ 120/208, 3 PH.

AND SOME USE #600 MCM THHN, CU @ 75DEG ?????

AMPACITY OF 500 MCM, THHN, CU @ 75 DEG IS 380A

TANX

 

[Fitzdrew516]

HI,
WHY SOME ENGINEERS FEED THE 400A METER SECTION BY @500 MCM, THHN,CU @ 75DEG @ 120/208, 3 PH.

AND SOME USE #600 MCM THHN, CU @ 75DEG ?????

AMPACITY OF 500 MCM, THHN, CU @ 75 DEG IS 380A

TANX

I think I understand what you're asking. Check out 240.4 (b)

 

[infinity]

If the load is 380 amps or less then you can go up to the next standard size OCPD which is 400 amps. Please turn off the Caps lock.