A NEMA type ___ enclosure offers only protection against incidental contact.

A NEMA type 1 enclosure is designed primarily for indoor use and provides protection against incidental contact with live parts. This type of enclosure protects equipment from non-hazardous environments where dust, dirt, and moisture might be present but does not offer a high level of protection against external elements or water. Consequently, its main function is to safeguard individuals from accidental contact with electrical components rather than providing a robust barrier against environmental factors.

In contrast, the other NEMA types mentioned offer varying levels of protection. For instance, type 2 enclosures provide protection against dripping water, while type 3 enclosures are designed for outdoor use, protecting against rain and windblown dust. Type 4 enclosures offer both protection against water immersion and the ability to withstand outdoor environmental conditions. Therefore, while type 1 focuses primarily on incidental contact, the other types provide greater protections suitable for harsher environments and more serious hazards.