B-Line Eaton series Type 3/3R junction boxes, 18" height, 4" length, 18" width, 3 and 12, Screw cover, WPSC enclosure, Surface mounted, Medium single

The 18184 WPSC measures 18 inches high, 18 inches wide, and 4 inches deep, which is where the 18-18-4 in the model number comes from. That 4 inch depth is the number to watch: it is shallow for a box this tall and wide, so check your wire bending space and device depth before you commit. Shipping weight is 17 lb, light enough for a one-man surface mount.

Surface mount only. The box has external mounting feet welded to the back, so it stands off the wall and bolts straight to a stud, strut, or masonry face with four fasteners. Because the feet are external, none of the mounting holes break the enclosure wall, which is what keeps the 3R rating intact. There is no flush or recessed trim option with this style.

It is a screw cover, not a hinged door. The flanged cover lifts completely off once the gasketed screws are backed out, which gives you full open access to the back pan for pulling and landing conductors. The trade-off is that on a box you open often, a hinged enclosure is easier to live with, since a loose screw cover has to be held or set down each time.

The body is 16 gauge carbon steel with a painted ANSI 61 grey finish. That is standard-duty industrial wall thickness for a box of this size, rigid enough for surface mounting on plant walls and structural steel. For washdown, coastal, or corrosive chemical areas, stainless or fiberglass is the better material choice than painted carbon steel.

The WPSC screw cover box ships as a blank enclosure, so conduit entries are field-drilled where you need them. That is normal for a Type 3R rated box, since factory knockouts would compromise the rating. Use rated hubs or watertight connectors on any hole you cut, and keep entries out of the top face so water is not sitting on a fitting.

It carries UL 50, the standard covering enclosures for electrical equipment, and it is manufactured in the United States. For a specifying engineer or facility buyer standardizing on one enclosure line, that pairing plus the Type 3/3R and 12 construction covers most general-purpose indoor and outdoor wiring pull and junction applications.

Medium single door describes the one-piece cover format on this size class, as opposed to a double-door enclosure where two covers split the opening. On the 18184 WPSC that means one flanged screw cover over the full 18 by 18 face, sealed to the body by an oil-resistant gasket.