SURGE ARRESTER WITH OVERVOLTAGE SENSITIVE GROUNDING SWITCH

摘要

A surge arrester for protecting power distribution equipment from overvoltages has a varistor as the active surge-arresting element. In the event of a persistent overvoltage, an amorphous conductor electrically in series with the varistor heats up to or above a critical temperature at which its tensile strength substantially decreases. The amorphous metal conductor breaks, triggering a series of events including the closing of a switch creating a permanent short to ground, operating the network overcurrent protection to deenergize the arrester and associated protected equipment, and protecting the electrical network equipment from insulation damage and/or failure because of a sustained or permanent power frequency overvoltage condition.