NEC 2002 310.15 and table 310.15 (B) (6)

[mollydodger]

Installing a 600 ampere 240 volt single phase residential service. As I read this NEC reference and table it does NOT allow smaller conductors for services over 400 amperes. That said I assume the service conductors (from the utility to the CTS) must be sized par 310.16. I plan on pulling two parallel 350 plus one 350 neutral per leg for the service lateral. Once I am on the load side of the CTS I will be running to a 200 ampere transfer switch (service rated) and two 200 ampere service disconnects. I believe I can use 310.15 and the table for these conductor sizes as well as for feeders to my sub-panels as they are below 400 amperes. Am I correct?? Thanks in advance!!!

 

[Dennis Alwon]

I believe that is what I would do but I think the underground service conductors only need be sized to the load-- 230.31

 

[suemarkp]

I depends on what those feeders and service conductors are serving. The 310.15(B)(6) table is to cover a complete dwelling unit. So if a 200A panel is serving all of the dwelling you can use the table (this implies the other 200A panels are going to other buildings). You cannot use 310.15(B)(6) for non-dwelling buildings, or portions of a dwelling, so subpanels generally can't use the table either.

I'm thinking you're going to have to use full size conductors, as most people who require a 600A service are probably going to have more than 200A in their main dwelling.