For raceway installations, conductors 8 AWG and larger must be stranded unless otherwise permitted or required in the NEC.

• A. they must be solid
• B. they must be stranded
• C. they must be stranded only in dry locations
• D. they must be copper-clad

Answer: (B)

The key idea is that in raceway installations, larger conductors are required to be stranded to ease pulling and protect the insulation during installation. When conductors are 8 AWG and larger, a solid conductor is very stiff, making it hard to pull through bends and long runs without risking insulation damage, kinking, or excessive tension at terminations. Stranded conductors, on the other hand, are much more flexible and can be pulled through conduit and bends more readily, distributing pulling forces across many strands and reducing the chance of damage. The NEC allows exceptions where solid conductors may be permitted, but the default requirement is for stranded conductors at this size in raceways.

Solid conductors would not fit the rule because they are too rigid for easy installation in raceways. Limiting the requirement to dry locations is not correct, since the requirement is size-based and applies regardless of location unless a listed exception applies. Copper-clad describes material composition and does not address the stranded versus solid construction requirement.