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

Yes, within the limits of a NEMA 3R rating. The 18124 RTSC is rated Type 3R, which covers outdoor use against falling rain, sleet and external ice formation, and it ships with a rain hood over the cover. It is not a washdown or hosedown enclosure, so keep it off surfaces that get pressure sprayed and mount it upright so the hood sheds water as intended.

It measures 18 inches high, 12 inches wide, and 4 inches deep. That 4 inch depth is the number to check first: it is a shallow wiring gutter more than a component enclosure, fine for splices, terminal blocks and small pull-through work, but tight if you are mounting a contactor or a DIN rail with anything stacked on it.

There are 5 knockouts in the bottom of the box. Everything else is blank, so any side, top or back penetrations you need have to be punched in the field, and on a 3R enclosure those should be sealed with rated hubs or fittings to keep the rain rating intact. Top penetrations are best avoided entirely on an outdoor 3R box.

It is a surface mount enclosure with embossed thru holes in the back pan, so it fastens straight to the wall or structure with your own anchors. No bracket or mounting kit is required. The embossed holes hold the back panel off the mounting surface slightly, which is what you want on an exterior wall so water is not trapped behind the box. At 11.5 lb empty, standard masonry or wood anchors handle it, but size for the conductors you are adding.

It carries UL 50, the standard covering enclosures for electrical equipment, and it is made in the US. If your drawing calls for a UL 50 Type 3R screw cover enclosure, the 18124 RTSC meets that callout. Order by model number 18124 RTSC.

No. A 3R enclosure is rated for falling rain, sleet and ice, not for dust, oil or directed water. If the location sees airborne dust or gets hosed down, you need a Type 12 for dust and dripping oil, or a Type 4 or 4X for hosedown and wind driven rain. The 18124 RTSC is the right box for an exterior wall, a pole, or an unheated equipment yard where the only exposure is weather from above.

The 18124 RTSC uses a flanged screw cover with plated screws, so the cover lifts completely away once the screws are out. That is the right choice for splice points and pull boxes you open rarely. If you are working inside the box regularly, or need one hand free on a ladder, a hinged door enclosure is the better pick because the cover stays captive. The tradeoff is cost and, on a screw cover, fewer moving parts to corrode outdoors.

The body is 16 gauge carbon steel, finished in painted ANSI 61 grey. That is the standard industrial grey, so it matches most existing panel gear and gutter runs on a plant or campus. Carbon steel with paint is fine for general outdoor and damp industrial locations, but in coastal salt air or a corrosive process area a stainless or non-metallic enclosure holds up better long term.