Final answer:
Metal wire ways are not permitted at heights above 6 feet but are allowed for other installations such as traveling through walls, in cases of severe physical damage, and horizontally for more than 328ft.
Step-by-step explanation:
The correct answer is option C, at heights above 6 feet. Metal wire ways are not permitted to be installed at heights above 6 feet. This is because they are not designed to support heavy loads and can pose a safety risk if installed at elevated heights.
Options A, B, and D are all permitted for metal wire way installations:
- Traveling transversely through walls is a common way to route electrical wires and cables.
- Where subject to severe physical damage, metal wire ways can provide protection for the wires and cables inside.
- Horizontally for more than 328ft is also permissible as long as the wire way is properly supported and installed according to industry standards.
Learn more about Metal wire way installations