By the time the (4) 4" conduits near the vault, it will be close to 360 in turn and would require a pullbox or vault anyway. It seems to me it would be nice if the same vault could be used.
I guess back to my original question, can you run 480V with 15KV conductors through a vault with a 12.47KV switch and conductors? As long as the insulation rating on the conductors are the same, aren't they allowed to be in the same enclosure/raceway?
NEC art.300.3 (C)2 Conductors of Different Systems
"In motors, switchgear and control assemblies, and
similar equipment, conductors of different voltage ratings
shall be permitted."
If the 15 KV cable and low voltage cable are connected to the same motor or same switchgear cell shall be permitted
"In manholes, if the conductors of each system are
permanently and effectively separated from the conductors
of the other systems and securely fastened to racks, insulators,
or other approved supports, conductors of different
voltage ratings shall be permitted.
Conductors having nonshielded insulation and operating
at different voltage levels shall not occupy the same
enclosure, cable, or raceway."
If the "vault" is a manhole in the above conditions it is permitted.
7anoter4, thanks for the response. I finally found that section last night, but I appreciate the response and confirmation.
I have been trying to see if there is another section that would prohibit the 480V feeders from entering the manhole if the feeders are for standby and emergency. The 480V feeders are from a generator located outside the building. Do you happen to know if there is any other regulations that would prohibit this?
I have been searching online for 600V 500MCM THWN or XHHW shielded conductors, but I seem to only come across instrumentation cable and type TC cable. I am going to call some manufacturers, but in the meantime, does anyone on here know of any wire manufacturers that has a product that would fit the bill?
