What precaution is essential when doubling an EHV breaker?

Ensuring good communication with the tester is essential when doubling an EHV (Extra High Voltage) breaker because this process involves high-stakes operations where safety is paramount. Effective communication helps to coordinate actions between team members, ensuring that everyone is aware of their roles, the current state of the system, and any potential hazards that may arise during the process. This becomes particularly crucial in a high-voltage environment, where misunderstandings can lead to dangerous situations, including electrical accidents or equipment failure.

The other options do not provide the necessary safety measures required during this complex operation. Relying solely on safety glasses does not account for the full range of personal protective equipment needed to safeguard against electrical hazards. Basic PPE only may not offer the comprehensive protection required when working with high voltage systems, where specialized gear is often mandatory. Furthermore, ignoring barricade tape signs would contravene safety protocols and increase the risk of unauthorized access to dangerous areas, further jeopardizing the safety of personnel involved in the task.