The MSUi series recessed plenum access LED surgical luminaire is a precision-engineered lighting solution designed to meet the demanding standards of modern surgical environments. Developed for installation in surgical suites, the MSUi provides both direct and supplemental lighting while allowing convenient plenum access through its inset door frame. Engineered for reliability, it delivers clean, uniform light across the operating field and surrounding zones. The fixture is commonly installed above the table perimeter using symmetric or asymmetric distributions, depending on the lighting requirements of the space. Built for rigorous hospital and surgical settings, the MSUi is UL listed for wet locations, cleanroom ISO-3 certified, and rated IP65 from below, ensuring dust-tight and water-resistant performance even during frequent cleaning and sterilization procedures.
Certified to Mil-Std-461G for electromagnetic compatibility, the MSUi is specifically designed for recessed mounting in surgical ceiling systems, as well as in grid and flanged installations. The luminaire’s shallow 4-inch profile makes it ideal for compact plenum spaces while maintaining full room-side access to all electrical components, simplifying maintenance and inspection.
Constructed from precision-formed, seam-welded 20-gauge cold-rolled steel, the housing offers superior rigidity and durability. Its hole-free TIG-welded seams ensure a completely sealed structure suitable for cleanroom environments. A closed-cell neoprene gasket seals the fixture flange tightly to the ceiling, preventing the ingress of contaminants. The inset door frame, also fabricated from 20-gauge cold-rolled steel with welded corners, is fitted with countersunk stainless-steel captive fasteners featuring integral silicone O-rings. Hinged with stainless-steel aircraft cables, the frame provides easy plenum access while maintaining a tight seal through a CertaSeal microcellular closed-cell gasket system, offering excellent chemical resistance and long-term resiliency.
The lens assembly is designed for optical performance and hygiene. A high-diffusion, impact-resistant acrylic lens—0.125 inches thick—provides uniform symmetric distribution, with optional symmetric or asymmetric designs available for specific task or perimeter lighting. The smooth external lens surface facilitates easy cleaning, while the lens is sealed to the door frame using 100% pure silicone RTV to ensure contamination control. Radiated emissions are minimized to meet Mil-Std-461G requirements without the need for metalized RFI grids, thanks to integrated filtering and advanced circuit design.
The triple-gasketed construction further enhances environmental protection. The lens, door, and housing are each independently gasketed, ensuring a hermetically sealed barrier against dust, moisture, and air infiltration. The door screws are equipped with silicone O-rings and flat-head sealing screws to preserve the fixture’s IP65 integrity under wet cleaning conditions.
The LED system utilizes high-efficiency board modules precisely regulated to ensure consistent color temperature, lumen output, and CRI performance. Available in 3000K, 3500K, 4000K, and 5000K color temperatures, the fixture maintains a color consistency of 3 SDCM and offers standard 80 CRI or optional 90 CRI. Specialized 525 nm green LED arrays are available either independently or in combination with white LEDs for surgical applications requiring color sensitivity. The LED modules provide an L70 lifetime exceeding 60,000 hours, ensuring longevity and stable performance.
The electrical system features a constant-current programmable electronic driver with 0-10V dimming down to 1%, offering precise control of brightness levels. It operates with high efficiency (>85%) and low total harmonic distortion (<10%), meeting both Mil-Std-461G and FCC Part 15 standards for conducted emissions. Power options include 120–277V or 347V AC input at 50/60Hz, with available driver configurations including DALI or Lutron™ dimming controls. Emergency drivers, when specified, are fully serviceable from the room side for convenience and safety.
Mounting flexibility is achieved through swing-style brackets for flanged installations and compatibility with 1-inch or 1.5-inch T-bar grid ceilings, with additional 2-inch T-bar support available as an option. The fixture operates within a temperature range of 4°F (-20°C) to 104°F (40°C), suitable for the controlled climate of surgical and medical facilities.
Finished with an antimicrobial gloss white polyester powder coat, the MSUi undergoes a five-stage pre-treatment process to ensure durability, corrosion resistance, and cleanliness. Its design not only complements the sterile aesthetic of surgical environments but also supports infection control protocols.
Certified and tested to UL (Canada & USA) standards for wet locations and recessed Type IC for insulated ceilings, the MSUi also meets NSF2 requirements for non-food and splash zones, with an optional food-zone certification available. The fixture is IEC60598 IP65 rated, ISO 3–8 cleanroom classified, and fully Mil-Std-461G certified, confirming its suitability for the most demanding healthcare and surgical applications where performance, reliability, and hygiene are paramount.
https://viscor.com/products/msui-plenum_access
