When are terminal slowdown devices required on a personnel hoist?

Terminal slowdown devices are essential safety features on personnel hoists, primarily designed to reduce the speed of the hoist as it approaches its terminal landing. The requirement for these devices is primarily informed by the operational speed of the hoist, as higher speeds can increase the risk of accidents during the stopping phase.

When a personnel hoist operates at speeds exceeding 150 feet per minute, the kinetic energy and momentum involved when approaching a stop become significant. At higher speeds, the need for a controlled deceleration becomes critical to ensure the safety of the passengers and to prevent mechanical stress on the hoist structure and landing skids. The terminal slowdown devices engage as the hoist nears its final destination, effectively reducing speed and allowing for a smoother and safer stop.

This understanding aligns with safety regulations which specifically stipulate that the installation of terminal slowdown devices is necessary at this threshold, making the answer particularly relevant for ensuring compliance and safety in elevator operations.