Metal encapsulated high pressure gas insulated bus duct - incorporates internal conducting rings as arcing points to absorb heat before circuit breakers act

摘要

The object is to assist in protecting the duct wall (1) against damage due to arcs between it and the central conductor. For this purpose local rings (2) are fitted to the inside of the duct wall. Each ring is electrically connected to the duct at one point but isolated over the remainder of its periphery. The intention is that an arc starting anywhere in the duct will quickly travel to the nearest arcing ring where the bulk of the heating will take place before the circuit is interrupted by the protection. The risk of burning a hole through the duct wall, and thereby necessitating extensive repairs, is thus greatly reduced.