Re: wire size
Originally posted by don_resqcapt19:
6 XHHW-2 400kcmil in one 3"
Don, for an OH service, wouldn't you probably use RMC? Per Table C.8, the max. # in 3" is 5 conductors for XHHW-2. You would need 3-1/2" if you used RMC. Same deal if you use IMC.
If you could use EMT, you could get by with 3". Per Table C.1, you can put 6 #400 XHHW-2 (or 6 #400 THHN) into 3" EMT.
Question: Why did you choose XHHW-2 over THHN? Both are rated 380A at 90 degrees.
You would have to derate either to 80% = 380X.80= 304A/wire, right?
Edited to add: Bob beat me to it while I was typing my reply and raiding the fridge!
[ September 24, 2005, 01:39 PM: Message edited by: tx2step ]