Which description correctly applies to the transition from conduit to knob-and-tube wiring?

Which description correctly applies to the transition from conduit to knob-and-tube wiring?

• A. A plastic box with unbushed holes
• B. A metal box or terminal fitting having separately bushed holes for each conductor
• C. A box with no holes
• D. A metal box with plain holes

Answer: (B)

When a wiring method changes, the conductors must be brought into a proper enclosure that protects and terminates them. The correct description reflects a metal box or terminal fitting that has separate holes for each conductor, each hole equipped with a bushing. This setup provides a listed, protected transition point, shields the insulation from sharp edges, and keeps the conductors separate and properly terminated. A box without bushings, or a plastic box with unbushed holes, would expose conductors to damage and fail to meet the protective requirements for a transition. A box with plain holes wouldn’t offer the necessary protection or termination capability either.

When a wiring method changes, the conductors must be brought into a proper enclosure that protects and terminates them. The correct description reflects a metal box or terminal fitting that has separate holes for each conductor, each hole equipped with a bushing. This setup provides a listed, protected transition point, shields the insulation from sharp edges, and keeps the conductors separate and properly terminated. A box without bushings, or a plastic box with unbushed holes, would expose conductors to damage and fail to meet the protective requirements for a transition. A box with plain holes wouldn’t offer the necessary protection or termination capability either.