Which device prevents the mast from being lowered or raised?

• A. Lock pin
• B. Pressure (anti jog) switch
• C. Mast brake
• D. Interlock relay

Answer: (B)

The action being tested is how the system blocks accidental mast movement and ensures that raising or lowering only happens with deliberate input. The pressure (anti jog) switch is designed to gate mast movement by requiring continuous, intentional pressure on the control to energize the drive. If the pressure is released or not sustained, the circuit opens and the mast stops, preventing any unintended raising or lowering from momentary touches, electrical noise, or tiny jog inputs. That focused control is why this device best prevents mast movement.

Other devices serve different roles. A lock pin is a manual lock that physically blocks movement when in place, not part of the normal control safety during operation. A mast brake provides a holding force to keep the mast from moving when engaged, but it doesn’t continuously gate motion the way an anti-jog switch does. An interlock relay enforces safe sequencing or prerequisite conditions, but it isn’t the specific mechanism that stops every lift or descent on a momentary input.