Method and apparatus for providing an environmental barrier between an interior and exterior of an electrical enclosure using a plug and seal

An electrical fixture, comprising:

• a knockout plug having plug sealing and interference surfaces;
• an electrical enclosure having
• a fitting surface complementary to the interference surface and forming an non-threaded interference fit with the interference surface;
• an enclosure-sealing surface positioned adjacent to the fitting surface;
• a pipe-fitting surface approximately coaxial with the enclosure sealing and fitting surfaces;
• and
• a seal seated circumferentially between said plug sealing and enclosure-sealing surfaces;
• wherein the seal provides an environmental barrier between interior and exterior portions of the electrical enclosure.

A method of providing an environmental barrier for a tapered-threaded knockout of an electrical enclosure, comprising:

• placing a seal on a knockout plug;
• and
• pressing the knockout plug into the tapered-threaded knockout to establish a non-threaded interference fit between the knockout plug and tapered-threaded knockout;
• wherein the knockout plug is detachably coupled to the tapered-threaded knockout, with the seal providing an environmental barrier between interior and exterior portions of the electrical enclosure.

An electrical system, comprising:

• an electrical enclosure comprising;
• a fitting surface that is operable to receive a non-threaded interference surface of a knockout plug, when a knockout plug is inserted;
• an enclosure-sealing surface adjacent the fitting surface that is operable to receive a seal, when the seal is inserted on the enclosure-sealing surface;
• a pipe-fitting surface disposed approximately coaxial with the enclosure sealing and fitting surfaces;
• and
• a light fixture coupled to the electrical enclosure;
• wherein the pipe-fitting surface is complementary to and operable to accept a conduit, when a conduit inserted past the fitting and enclosure-sealing surfaces.