What is required for luminaires made of insulating material that are directly wired?

For luminaires made from insulating materials that are directly wired, it is essential that they have no exposed conductive parts. This requirement is crucial because it ensures that the luminaires are safe to use, minimizing the risk of electrical shock to users. Insulating materials are typically chosen to prevent electrical conduction. Thus, if there are no exposed conductive parts, it eliminates potential pathways for electricity to flow outside of the intended circuit, enhancing overall safety.

The reason for specifying that there should be no exposed conductive parts is also tied to the proper handling and maintenance of the luminaires. If conductive parts were exposed, even within an insulating housing, it could lead to situations where someone might accidentally touch an energized part, leading to serious hazards.

While accessibility is also important for maintenance and replacement, and bonding can enhance safety in some cases, these do not directly address the core requirement for luminaires made from insulating materials. Thus, the correct answer emphasizes the necessity of safety through the absence of exposed conductive parts.