NEIEP Mechanics Practice Exam

What must be done before checking pump drive belts on a hydraulic elevator?

1. Close the hydraulic fluid valve

2. Pull the main disconnect switch

3. Activate the emergency stop button

4. Disconnect power to the pump motor

The correct answer is: Pull the main disconnect switch

To ensure safety and compliance with established procedures before inspecting pump drive belts on a hydraulic elevator, it is essential to pull the main disconnect switch. This action effectively ensures that all electrical power to the elevator system is completely turned off, which is critical for preventing accidental activation of the hydraulic system during maintenance. When the main disconnect switch is pulled, it protects the technician from electrical hazards and the risk of the elevator inadvertently moving or the pump operating while the technician is working on the belts. Proper lockout/tagout procedures are vital when servicing any equipment to eliminate the possibility of energy release that could cause injury. While closing the hydraulic fluid valve, activating the emergency stop button, or disconnecting power to the pump motor may have their own safety implications, they do not provide the comprehensive disconnection from all electrical power sources that pulling the main disconnect switch ensures. This makes it the most important step before any maintenance work is performed on the hydraulic elevator's drive system.