Orbit MB-3 Masonry Box 3 Gang 3.5 Inch Deep

Product Description

The ORBIT MB-3 is a 3-gang masonry electrical box designed for flush installation in brick, block, concrete, and other masonry wall assemblies. At 3.5 inches deep, it provides adequate volume for device mounting and wire management in demanding rough-in conditions. This box is installed by licensed electricians during the masonry phase of construction, before wall finishing, making proper placement critical to final device alignment. Its depth accommodates standard receptacles, switches, and low-voltage devices where code-required fill calculations are satisfied by the installer.

The MB-3 is suited for new commercial and residential masonry construction as well as retrofit work in existing block or brick walls. Three-gang configurations are common in commercial corridors, mechanical rooms, panel areas, and other locations requiring multiple devices in a single rough-in location. The box is set in place during block laying or core drilling and secured before mortar cures, requiring coordination between the masonry and electrical trades.

Key Features

• 3-gang configuration supports installation of up to three devices in a single location
• 3.5 inch depth provides wire fill volume for multi-device rough-in
• Designed for direct embedment in masonry walls including brick, block, and concrete
• Standard masonry box footprint compatible with common gang plate and cover configurations

Compatibility

Designed as an OEM-style masonry electrical box for 3-gang device installations in masonry wall construction. Accepts standard 3-gang wallplates and device straps per typical NEC rough-in requirements.

Installation Notes

Installation is performed by a licensed electrician in coordination with the masonry trade. De-energize all circuits in the work area before making any wiring connections. The box must be set level and plumb at the correct depth relative to the finished wall surface before mortar or grout sets. Refer to NEC Article 314 for box fill calculations and mounting requirements applicable to this device type.

Technical Specifications

• Gang Size: 3 Gang
• Depth: 3.5 inches
• Weight: 14.5 pounds
• UPC: 83524301026

Standard Information

• Brand: ORBIT
• Manufacturer Part Number: MB-3