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Cable spacing

Cable spacing

Cable spacing

(OP)
Is there any derating factor that can be used when using 500MCM cables? I am currently running 27 cables to a breaker, but I would like to minimize the spacing to less than 100% spacing. IS this possible?  

RE: Cable spacing

Sure, but it lowers the ampacity of the conductor and increase the number of conductor, resulting in more total space required.  There is a reason that the ampacity in tray with proper spacing is higher than the ampacity in conduit.

RE: Cable spacing

(OP)
Would you happen to know which table in the CEC would have these derating factors? I mean with respect to spacing?

RE: Cable spacing

Tables
1
2
3
4
5B
5C
5D
Rules
4-004
8-104
12-2210
26-142
42-008
42-016
Appendix B Notes on Rules
4-0004
8-104
 

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Cable spacing

There are hugh derating factors for adjacent AC cables.  I recommend that you contact your manufacturer, ask for applicaiton engineering. They typically have models which they can use to give you a conservative estimate.

Benjamin Lanz
Past Chair of IEEE 400
Sr. Application Engineer
IMCORP- Power Cable Reliability Consultants

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