Section 4 - Conductors

Question 1

What options do we have when dealing with sheath currents in single-conductor cables? And name the rule.

Answer 1

1-Derating the allowable ampacity of the conductor to 70% (Rule 4-008 1) a))

2-Derating according to cable manufacturer’s recommendations, though this may be done only with special permission(Rule 2-030). (Rule 4-008 1) b))

3-Eliminating sheath currents, which is typically accomplished by bonding the cable’s sheaths to ground at the supply end only (see Appendix B reference to Rule 4-008) (Rule 4-008 1) c))