You are placing an entrance cable between two buildings connected by a conduit 205.3 m (588 ft) in length. What would be the MAXIMUM length of unlisted OSP cable that could be used before you terminate the cable or transition it to a listed cable?

Question

Quizplus · Accepted Answer

According to NEC 830.6(A), the maximum length of unlisted OSP cable that can be used for an entrance cable between buildings is 200 m (656 ft). However, for cables installed within a conduit, NEC 830.24(A) allows for an additional 5% cable length, which would bring the maximum length up to 210 m (689 ft). However, the conduit length of 205.3 m (588 ft) is already very close to this limit, and considering potential cable slack, termination space, and future maintenance needs, it is best to err on the side of caution and terminate or transition the cable before reaching the full 210 m limit. Therefore, the best choice is C, 209 m (686 ft).

You Are Placing an Entrance Cable Between Two Buildings Connected