Chief - Legrand CMS491C Plenum Rated Storage Box

Product Description

The CHIEF - LEGRAND CMS491C is a 1x2 plenum-rated storage box designed for use in air-handling ceiling spaces where building codes require low-smoke, low-flame materials. This enclosure provides a secure mounting cavity for small AV or low-voltage components installed above drop ceilings in commercial and institutional environments. Its plenum rating means it meets the fire and smoke requirements for installation in HVAC return-air plenums without requiring additional conduit or enclosure upgrades. Low-voltage installers and AV integrators working in commercial spaces will find this box suitable for organized, code-compliant component storage.

This storage box is intended for 1x2 grid ceiling systems commonly found in commercial offices, schools, healthcare facilities, and other multi-room AV or low-voltage installations. It fits into standard suspended ceiling grid layouts and is sold as a single unit. It is a wall mount category product well suited to organized cable and component management in plenum ceiling spaces where code compliance is a requirement.

Key Features

• Plenum-rated construction meets fire and smoke requirements for air-handling ceiling spaces
• 1x2 form factor fits standard suspended ceiling grid systems
• Provides enclosed storage for small AV or low-voltage components above the ceiling plane
• Single-unit packaging for straightforward procurement and installation

Compatibility

Designed as an OEM-style replacement and standard accessory for 1x2 suspended ceiling grid installations requiring plenum-rated component enclosures.

Installation Notes

Installation should be performed by a qualified low-voltage technician or AV integrator familiar with suspended ceiling systems and local building codes. Power down any connected low-voltage circuits before securing components inside the enclosure. Verify that the installation location qualifies as a plenum air-handling space under local code before relying on plenum-rated materials as a conduit substitute. Consult applicable NEC sections governing low-voltage wiring in plenum environments prior to final installation.