UFES retrofit delivers ultra-fast ARC-FAULT PROTECTION

摘要

DAVID HUGHES, OF ABB POWER PRODUCTS, EXPLAINS HOW THE ULTRA-FAST EARTHING SWITCH (UFES) COMBINES THE ADVANTAGES OF VACUUM INTERRUPTER AND IS-LIMITER TECHNOLOGY TO ENABLE MEDIUM-VOLTAGE SWITCHGEAR TO BE RETROFITTED WITH ULTRA-FAST, ACTIVE, ARC-FAULT PROTECTION. IN RARE CASES, a failure inside a medium-voltage switchgear cabinet, due to a defect, exceptional service condition or incorrect operation can cause an internal arc which presents a significant hazard. This is due to the instantaneous increase in temperatures at the fault location to around 20,000℃, well above the melting point of steel, copper and insulation materials. Internal components are vaporised and the sudden release of heat and plasma (ionised gas) creates an explosive blast. Should an arc-fault occur, protecting any personnel in the vicinity is the main priority. It is much better though to take active measures to prevent such an event from happening in the first place. This not only eliminates any risk for personnel, it also offers protection against damage and even destruction of system components. There is now a solution in the form of the ultra-fast earthing switch (UFES) internal arc protection system that combines ABB's fast acting vacuum interrupter and the world's fastest limiting and switching device - the Is-limiter.