Identify a safety protocol when conducting routine maintenance on elevator door operators.

When conducting routine maintenance on elevator door operators, one of the most critical safety protocols is disconnecting power before starting any maintenance work. This step is essential to ensure the safety of maintenance personnel by eliminating the risk of electric shock, which could occur if the equipment were inadvertently activated while someone is working on it. Disconnecting power isolates the electrical components and creates a safe working environment.

This protocol also helps prevent accidental movement of the elevator door or other mechanical parts, which could lead to injuries. By prioritizing this safety measure, maintenance professionals can perform their tasks with reduced risk, allowing them to focus on the maintenance itself without constant concern for potential hazards associated with powered equipment.

The other options, while they may contribute to overall safety and efficiency, do not have the same level of immediate impact on preventing accidents or injuries during maintenance work.