Sizing a JB

[ATORRES@EQUINIX.COM]

We have a submarine cable 15KV DC coming into a J-box in a 4 inch conduit with 4 spare 4 inch conduits and 2 spare 2" conduits. We are pulling the cable straight threw the J-box can you advise what size J-box is required by NEC??

 

[Dennis Alwon]

We have a submarine cable 15KV DC coming into a J-box in a 4 inch conduit with 4 spare 4 inch conduits and 2 spare 2" conduits. We are pulling the cable straight threw the J-box can you advise what size J-box is required by NEC??

It depends on the layout of the other conduits. Are they straight also?

 

[Smart $]

Also depends on whether the conduit entries are in a single row or more than one. If more than one row, the calculation is made per row... and the largest result is the minimum for that dimension.

 

[templdl]

May it be in regard o the bending radius limitations when terminating cable on a breaker or bus which would influence the size of the enclosures as well as what what the minimum requirements were to UL list the enclosure and mount a device in it?
The minimum bending requirements of NEC 312 would apply to understanding.

 

[Joe Villani]

Sizing a JB

Over 600 volts conduit size is not the determining factor.

You have to base the sizing on the diameter of your cable over sheath.

See 314.71(A) for straight pulls.

Joe Villani

 

[Dennis Alwon]

Joe thanks for the correction. I passed right over the 15KV statement. The drawings I used are for 1000V and less