Which device stops the platform before striking an obstruction?

Which device stops the platform before striking an obstruction?

• A. Top Final Limit Switch
• B. Electrical Limits
• C. Micro Switches
• D. Final Terminal Stopping Devices

Answer: (C)

Micro switches act as obstruction detection sensors on an escalator. They’re positioned to sense anything blocking the path of the step or comb plate, and when they’re actuated, they immediately send a stop signal to the drive controller so the platform halts before contact occurs. This rapid, localized sensing is specifically what protects against hitting a person or object in the run. The other devices serve different purposes: final limit switches and final terminal stopping devices control end-of-travel stopping, not obstructions along the way, and electrical limits refer to general limit-switch functions in the control circuit. So the device that stops the platform before striking an obstruction is the micro switches.

Micro switches act as obstruction detection sensors on an escalator. They’re positioned to sense anything blocking the path of the step or comb plate, and when they’re actuated, they immediately send a stop signal to the drive controller so the platform halts before contact occurs. This rapid, localized sensing is specifically what protects against hitting a person or object in the run. The other devices serve different purposes: final limit switches and final terminal stopping devices control end-of-travel stopping, not obstructions along the way, and electrical limits refer to general limit-switch functions in the control circuit. So the device that stops the platform before striking an obstruction is the micro switches.