An electrician needs to install a surface-mounted, nonmetallic, weatherproof cabinet on the outside of a concrete block building. How many inches of airspace must there be between the cabinet and the wall?

When installing a surface-mounted, nonmetallic, weatherproof cabinet on an exterior wall, it is important to understand the requirements for airspace, especially regarding the cabinet's performance and safety. For nonmetallic cabinets, there is typically no specific airspace requirement mandated by the National Electrical Code (NEC). These cabinets are designed to be mounted directly against the surface of the wall, allowing for a streamlined installation and maintaining a weatherproof seal at the installation point.

In this scenario, having no airspace (meaning the cabinet can be installed directly against the wall) is acceptable and aligns with installation guidelines for nonmetallic enclosures. This facilitates a proper fit, helps prevent water accumulation, and prevents issues related to debris that might otherwise gather in a larger airspace around the cabinet.

Thus, when installing such cabinets, adhering to the guideline of zero inches for airspace is both compliant with electrical code standards and practical for maintaining the integrity of the installation.