Which device operates before the normal stopping device obstruction?

• A. Platform Hand
• B. Top Terminal Limit Switch
• C. Obstruction Sensing Device
• D. Masonry Anchors

Answer: (B)

The Top Terminal Limit Switch is the device that stops the escalator as the car reaches the upper landing. It is tied to the machine’s position, so it acts as part of the normal stopping sequence before any obstruction-related action would be engaged. In other words, it halts the drive train based on reaching the top, which can prevent an obstruction scenario altogether. Obstruction Sensing Device only responds to something blocking the steps, and would come into play if an obstacle is present, but the top terminal limit switch acts earlier in the stopping sequence. Masonry anchors and platform-related components aren’t part of this pre-stop safety act.