Steel City 52151 VX 4-Inch Square Steel Outlet Box, 21 in³, MC Clamp

The Steel City 52151 VX is a 21 cubic inch 4 inch square steel box. Under the NEC box fill table, 12 AWG conductors count 2.25 cubic inches each, so 21 cubic inches supports nine 12 AWG conductors before deductions, or eleven 14 AWG at 2.0 cubic inches each. Remember the internal cable clamps and any device and grounding conductors take their own deductions out of that same 21 cubic inches, so a box with a device yoke and a ground will carry fewer current-carrying conductors than the raw number suggests.

Yes, the 52151 VX has integral MC clamps built into the box, so no separate connector is needed to land MC cable. That is the difference between this box and a plain knockout box, where you buy MC connectors separately for each run.

It measures 4 inches by 4 inches by 1-1/2 inches deep. At 1-1/2 inches of depth it sits well inside the 3-1/2 inch cavity of a 2x4 stud wall, with room behind for conductors. Keep the front edge flush with the finished wall surface so a raised cover or plaster ring brings the device out to the drywall face.

A 4 inch square box is an open box, so plan on a separate cover: a flat blank cover, a single or two-gang device ring, or a raised plaster ring sized to your wall thickness. None of that is included, the box is sold each. Note the ring's own volume adds to the box's 21 cubic inches for fill purposes.

The 52151 VX is a steel 4-inch square outlet box with an MC clamp, built for dry interior work where the cable is run indoors. For an exposed exterior receptacle, the Mulberry Royal Mountie weatherproof outlet box is a die-cast aluminum 1-gang box intended for weatherproof use, and the Thomas & Betts 2IH3-1 Red-Dot is a 2-gang conduit outlet box with three 1/2-inch hubs for threaded conduit entry outdoors.

Yes. The 52151 VX body is steel and uses an MC clamp to terminate armored cable. If the job is non-metallic cable in residential walls, the Cantex EZ Box series is a PVC multi-gang residential outlet box. Note the difference in gang configuration: the 52151 VX is a 4-inch square, 4 by 4 by 1-1/2 inch box with 21 cubic inches of volume, while the EZ Box is offered as a multi-gang device box.

No. The 52151 VX is a standard steel 4-inch square outlet box with 11 knockouts and an MC clamp, listed under UL E2969 for general wiring. Classified locations call for an explosionproof box such as the Appleton GRJ series or GRJS universal conduit outlet box, both malleable iron explosionproof designs, or the Appleton GRT75 malleable iron round conduit outlet box.

Eleven knockouts, spread across the sides and the back of the 4 inch square body. That gives you a choice of entry points for conduit or cable runs, feed-through wiring, and a back entry where the run comes in behind the box. Unused knockouts must stay closed or be filled with a knockout seal.

The 52151 VX carries UL file E2969. It is a drawn steel box, made in the United States, which is what most commercial and multi-family specs call for over a nonmetallic box.

Use the steel 52151 VX where the spec calls for a metal raceway or armored cable, since the box bonds through the MC clamp and conduit connections and gives you eleven knockouts to work with. Where the job is residential NM cable and a nonmetallic box is acceptable, a PVC box such as the Cantex EZ Series multi-gang residential outlet box is the usual alternative. For a hazardous location neither applies, that calls for an explosionproof malleable iron box like the Appleton GRJ or GRJS Series.

The 52151 VX is a 4-inch square, 21 cubic inch steel box with an MC clamp, sized for general device and splice work. A range or dryer connection is usually made with a purpose-built assembly instead, such as the Pass and Seymour P242RRD range and dryer box, which is a thermoplastic unit made for that application.

The 52151 VX is a drawn steel 4-inch square box, 4 by 4 by 1-1/2 inches, with 11 knockouts and a built-in MC clamp, so armored cable lands directly in the box. The Thomas and Betts 2IH3-1 Red-Dot is a 2-gang conduit outlet box with three 1/2-inch threaded hubs, so raceway threads into the box rather than cable being clamped; it is supplied in a pack of 100, while the 52151 VX sells each.