When is it permissible to leave a telescopic boom crane with the engine running?

Leaving a telescopic boom crane with the engine running is permissible in situations where the operator can observe unauthorized entry. This is primarily to ensure safety and security on the job site. If the crane is left running, it enables the operator to respond quickly to any potential threats or intrusions, helping to prevent accidents or unauthorized access to the crane’s operating area.

In scenarios such as refueling, load testing, or maintenance, it's generally not advisable to leave the engine running due to safety concerns. Refueling poses a fire hazard, load testing requires focused attention, and maintenance often involves working closely with the machine, both of which typically necessitate the engine being turned off to ensure the safety of personnel and the equipment itself.