3ph Service Conductors

[bwat]

480V 3ph 2000A service from utility

Is there any scenario where you would need 5 conductors from utility's transformer to customer's equipment?

In my mind, the answer is no. Your MBJ is at customer's equipment and this creates your separation of neutral and EGC. Upstream from MBJ, a 5th wire would do nothing for you.

Second guessing...

 

[roger]

Agreed. If you did have a five wire service the MBJ would have to be eliminated and a separate ground bar added.

 

[infinity]

Since this is a service you would never have 5 conductors unless one of them was a SSBJ bonding a metal raceway.

 

[bwat]

Thank you both!