3/0 XHHW is rated 200 amps @75c.
4/0 XHHW is rated 230 amps @75c.
per NEC 240.4B & 240.6 is it allowable to use 3/0 on a 225A ckt bkr? (for a non-continuous rated load).
my colleague says you cannot use 3/0 since there is an OCD rating of 200A so 3/0 cannot exceed this established OCD rating. the argument is that the next OCD rating of 225A must use 4/0 since 3/0 cannot go up to the next higher rating because it is locked in at 200A.
this is a big deal since there is an existing 2 inch conduit that can be utilized and the smaller 3/0 conductor would help the installation. (this feeder is not continuously rated.)
4/0 XHHW is rated 230 amps @75c.
per NEC 240.4B & 240.6 is it allowable to use 3/0 on a 225A ckt bkr? (for a non-continuous rated load).
my colleague says you cannot use 3/0 since there is an OCD rating of 200A so 3/0 cannot exceed this established OCD rating. the argument is that the next OCD rating of 225A must use 4/0 since 3/0 cannot go up to the next higher rating because it is locked in at 200A.
this is a big deal since there is an existing 2 inch conduit that can be utilized and the smaller 3/0 conductor would help the installation. (this feeder is not continuously rated.)
