The Yale 300 HO Selectable closer's engineering centers on its hydraulic rack & pinion mechanism, a well-established and efficient system for controlled door closure. Within the cast aluminium body, a spring-loaded piston is connected to a rack gear. As the door opens, the pinion, driven by the door arm, compresses the spring and forces hydraulic fluid into a reservoir. Upon release, the compressed spring drives the piston and rack, turning the pinion to close the door. The control of this movement is precisely regulated by adjustable valves that restrict the flow of hydraulic fluid. The independent closing speed valve governs the primary sweep of the door, while the latching speed valve controls the final few degrees of closing, ensuring the door overcomes latch resistance without slamming. This dual-valve system provides granular control over the door's kinetic energy dissipation.
EN 1154 certification is a critical technical validation, signifying that the Yale 300 HO Selectable meets the European standard for controlled door closing devices. This standard dictates strict requirements for power size, durability, efficiency, and safety. Its classification as 'Selectable EN 2/3/4' indicates it can be adjusted to deliver specified closing forces and closing times as defined by EN 1154, ensuring consistent and predictable performance over a wide temperature range and throughout its extensive 500,000 cycle lifespan. This robust cycle test rating underscores the closer's mechanical integrity and the longevity of its hydraulic seal system.
Door control precision is paramount. The selectable power sizes (EN 2/3/4) allow engineers and installers to match the closer's force output precisely to the door's mass and dimensions, optimizing user effort and closer efficiency. The absence of back-check implies that the door's opening motion is not hydraulically cushioned at its extreme, and the lack of delayed action means the door will begin its closing sequence immediately after release. Crucially, while UL Listed and EN 1154 certified for performance, this specific Yale 300 HO Selectable model is explicitly *not fire-rated*. This technical distinction means it is unsuitable for installation on fire-rated door assemblies where a self-closing device without a hold-open function is typically mandated for life safety and compartmentalization strategies. Its integrated hold-open arm, while convenient, further reinforces its application in non-fire-rated scenarios where temporary door retention is desired.
