What condition can lead to catastrophic failure in an EHV breaker?

The potential for catastrophic failure in an Extra High Voltage (EHV) breaker is primarily linked to the loss of insulating medium. EHV breakers rely on insulating media, such as gas or oil, to maintain proper functioning and to prevent electrical arcing. When this insulating medium is compromised—due to leaks, degradation, or other failures—the risk of electrical breakdown significantly increases. This can lead to arcs forming within the breaker, causing severe damage to the equipment and potentially resulting in system-wide failures.

Without the necessary insulation, components within the breaker can short-circuit, causing excessive heat and leading to further mechanical failures. In scenarios where the insulating medium is lost, the entire system can disrupt service and create dangerous conditions for both equipment and personnel.

Other factors such as using old connectors, low power supply, or overheating tank heaters contribute to operational inefficiencies or maintenance issues but do not directly result in catastrophic failures like the loss of insulating medium does. The loss of insulation fundamentally threatens the safety and reliability of the breaker in handling high voltage operations.