When conducting a preoperational check on a digger derrick, how should the qualified electrical worker operate the unit?

When conducting a preoperational check on a digger derrick, it is essential for the qualified electrical worker to operate the unit through the range of all functions. This comprehensive approach ensures that all mechanisms are functioning properly and that there are no hidden issues that could potentially lead to safety hazards during operation.

Testing only specific functions does not provide a complete picture of the machine's performance, as it could miss potential problems in other areas. Rotating the unit in just one direction limits the assessment of the equipment's capabilities and may overlook malfunctions that occur in other operational modes. Additionally, quickly turning the unit on and off does not offer any meaningful insight into the performance or safety of the machine.

By operating through the entire range of functions, the worker can verify that all systems are responsive and safe to use, promoting a safer working environment and reducing the risk of malfunctions during actual operations.