Which of the following safety precautions should be taken when operating an excavator?

Ensuring safety while operating an excavator is paramount, and checking for overhead obstacles and maintaining visibility is a critical precaution. This practice helps to prevent accidents related to overhead wires, branches, or other structures that could pose a danger while the excavator is in operation. By being aware of the surroundings, the operator can avoid potential collisions, which may lead to equipment damage, personal injury, or even fatalities. Good visibility also allows for more effective communication with ground workers, enhancing overall safety on the job site.

The other choices, such as using the excavator only at night, operating with the cabin door open, and ignoring communication with ground workers, all introduce unsafe practices that could endanger the operator and those nearby. Therefore, the focus on checking for overhead obstacles and maintaining visibility is essential for safe excavator operation.