Which type of EHV breaker features interrupting contacts that are enclosed in tanks at ground potential?

The dead tank breaker is characterized by its interrupting contacts being housed within a tank that is at ground potential. This design provides several significant advantages. Because the contacts are enclosed in a grounded tank, there's improved safety for workers and reduced risk of electric shock during maintenance tasks. Additionally, the dead tank breaker is less susceptible to environmental conditions, as the enclosed design protects the components from dirt, moisture, and other external factors that could affect performance.

The dead tank breaker operates by isolating the circuit at ground potential, which also aids in minimizing the risk of faults and enhances the overall reliability of the breaker during operation. The construction of the dead tank design means that any potential fault or electrical event is contained within the tank, which helps in preventing arc flash incidents and maintaining safe working environments around high-voltage equipment.