Which device is used to lower the unit manually?

• A. Platform Control Wiring
• B. Manual Relief Valve
• C. Drive Types
• D. Hoistway Limit Switches

Answer: (B)

When you need to lower the unit without using the normal drive, you rely on a valve that can release hydraulic pressure so the car can descend at a controlled rate. The device designed for this purpose is the manual relief valve, which opens to vent pressure in the hydraulic circuit and allow the hoist to lower even if the drive system isn’t active.

Platform control wiring handles the electrical signals that operate the controls; it doesn’t directly control lowering. Drive types describe how the unit is powered and moved, not how you manually lower it. Hoistway limit switches act as safety stops to prevent overtravel, not to provide manual descent.

So, to lower the unit manually, the manual relief valve is used. This should be operated only by trained personnel following proper procedures.