Which device is not required for direct-plunger or roped hydraulic lifts?

• A. Stopping Devices
• B. Obstruction Sensing Device
• C. Top Terminal Limit Switch
• D. Interlock Wiring

Answer: (A)

Direct-plunger and roped hydraulic lifts manage travel primarily through hydraulic control and end-of-travel limits, rather than a separate stopping mechanism. The safety features that are required at a minimum include an obstruction-sensing device to prevent door closure if someone or something is in the doorway, a top terminal limit switch to prevent the car from exceeding its designed travel, and interlock wiring to ensure doors and gates stay coordinated with the car’s position. A separate stopping device isn’t needed for these lift types because the hydraulic control system and end-of-travel devices already handle stopping and travel termination. So, stopping devices are not required.