Fill in the blanks with the appropriate answer.
When determining ampacities of conductors rated between 2,001V and 35,000V, where shields are grounded at more than one point, ampacities shall be adjusted to take into consideration the _________due to ____________, and tables other than those listed in Sec. 310.60(C)(69), (70), (81), (82), may contain ampacities with shields grounded at multiple points.
A) shield / different types
B) heating / shield currents
C) termination / circulating currents
D) shield / circulating currents
Find the Answer
Answer: B
Section 310.60 of the 2014 NEC outlines the general wiring requirements for conductors rated 2,001V to 35,000V. As noted in Section 310.60(B)(1) [Grounded Shields], “Ampacities shown in Table 310.60(C)(69), Table 310.60(C)(70), Table 310.60(C)(81), and Table 310.60(C)(82) shall apply for cables with shields grounded at one point only. Where shields for these cables are grounded at more than one point, ampacities shall be adjusted to take into consideration the heating due to shield currents.”
Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at [email protected].
