When using extension rings, what must be done with noncombustible surfaces?

The correct response highlights the importance of ensuring a proper seal around extension rings on noncombustible surfaces. When installing an extension ring, it is essential to address any gaps or incomplete areas to maintain the integrity of the installation and ensure safety and code compliance.

Noncombustible surfaces might be present in various environments, and these surfaces need to be properly finished to avoid potential hazards, such as the ingress of water or pests. Any gaps left unaddressed could compromise the stability of the installation and possibly lead to electrical faults or failures.

The NEC specifies that all electrical installations must be done in a safe manner, with particular attention to preventing any potential hazards. Therefore, repairing gaps ensures that the enclosure is complete and helps prevent damage from environmental conditions while providing a safe connection for electrical components. This approach reinforces safety and reliability in compliance with the NEC standards.