Are there standard cable resistances when none are available?

[tricard]

Good afternoon,

I regularly perform short circuit and arc flash studies and throughout the various plants that we analyze there is always one or two runs of cable that has no resistance information given in my known library of documents. I was wondering if there is an IEEE (or otherwise) standard for resistances of cables that have no manufacturer data?

Thanks for the help,

Tim

 

[dbaird]

NFPA 70 National Electrical Code, 2008 Table 400.5(A) & Table 400.5(B).

NFPA 79 Electrical Standard for Inustrial Machinery, 2007 Table 12.5.1 & Table 12.5.5(b).


David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[dpc]

If you are doing short circuit studies, I'd recommend getting a copy of "A Practical Guide to Short-Circuit Calculations" by Conrad St. Pierre. He has tables for typical cable impedances for a variety of conductor types, along with a wealth of other data.

 

[tricard]

Thanks dpc. it looks like the appendix in that book has everything I need for the impedance data.