The 4" surgical LED downlight is a precision-engineered fixture developed to meet the demanding requirements of modern surgical and healthcare environments. Designed to provide supplemental lighting for general surgical procedures and primary lighting for minimally invasive operations, it delivers clean, uniform light with exceptional visual comfort. Its carefully controlled low cutoff angle minimizes glare reflected from monitors and glossy surfaces commonly found in operating rooms, supporting a clear visual field for surgical staff. These luminaires feature a gasketed, flush-lensed design that forms an airtight seal at the ceiling, effectively preventing contaminated air from entering the surgical area and maintaining the sterile integrity of the environment.
Engineered for reliability, the MSD series provides up to 5000 lumens of output with full-range dimming capability down to 1%, allowing surgical teams to precisely control light levels as needed. Each fixture comes standard with protection against electromagnetic and radio frequency interference, certified to meet the stringent MIL-STD-461G standard. Built to CSA and UL standards, the downlight is NSF certified and rated IP65 (flush lens) or IP64 (regressed lens), ensuring superior performance in wet or sterile zones. Available in multiple color temperatures ranging from 2700K to 5000K and CRI options of 80+, 90+, and 97+, the fixture offers outstanding color rendering accuracy vital for medical visualization and precision work.
The downlight’s robust construction begins with an 18-gauge rigid steel installation frame equipped with vertically adjustable butterfly brackets and a large junction box featuring five ½-inch trade-size knockouts. A plaster ring allows post-installation adjustment from below the ceiling for thicknesses up to 2.5 inches. The optical assembly is fully factory-sealed to preserve its clean appearance and protect internal components from contamination. It incorporates a heat sink, reflector, lens, and trim, all sealed with long-life EPDM closed-cell gasket materials and supported by torsion springs connected to a vertically adjustable collar.
The fixture’s lens is crafted from 0.125-inch thick, high-impact polycarbonate with a smooth, clear surface that resists impact and allows effortless cleaning. Secured by a die-cast ring and trim, the lens assembly maintains continuous compression against the reflector and gaskets, ensuring a lasting airtight seal. Die-cut EPDM foam gaskets further secure the lens-to-trim interface, preventing air or particulate leakage.
At the heart of the luminaire is a factory-sealed, chip-on-board (COB) LED light engine that is both field-replaceable and serviceable from below the ceiling. These high-efficiency LEDs are tightly regulated to maintain consistent CRI, color quality, lumen output, and efficacy across the fixture’s lifetime. With a color consistency within 2 SDCM and an L70 lifetime exceeding 60,000 hours, the system ensures enduring performance and visual stability in critical environments.
The electrical system features a constant-current programmable driver that operates at high efficiency (greater than 85%) with low total harmonic distortion (below 10%). It supports smooth dimming to 1% via 0-10V control and is available in 120–277Vac or 347Vac versions. Designed to meet MIL-STD-461G standards, the driver’s electronic filtering effectively suppresses both conducted and radiated EMI emissions, ensuring uninterrupted operation of sensitive surgical equipment. Optional DALI-compatible driver configurations are also available.
Each trim is finished through a five-stage pretreatment process followed by a durable antimicrobial polyester powder coating in gloss white, with a matte white antimicrobial finish available as an option. The fixture installs recessed into non-IC-rated ceilings and is compatible with various grid systems, including 9/16”, 15/16”, 1”, and 1.5” T-bar configurations, as well as drywall (F-type) ceilings. Its plaster ring provides vertical adjustment to accommodate ceiling thicknesses from ½” to 2.5”, and all installations must be under a covered structural ceiling for optimal safety and compliance.
The 4" surgical LED downlight is ETL-listed for recessed non-IC installations and wet locations, NSF2-certified for splash zones, IP65-rated for room-side protection, and ISO Class 3 cleanroom rated when configured with FSL or FSS trims. With MIL-STD-461G certification ensuring electromagnetic compatibility and a rugged, sealed design that upholds sterile conditions, this specification-grade luminaire is ideally suited for hospitals, surgical suites, and healthcare environments where performance, hygiene, and reliability are paramount.
https://viscor.com/products/msd-4
