| 摘要 |
<p>The excess voltage protection system for an electrical supply with distributor rails and a potential equalising rail, has the protective switch and the protective conductor in a common housing. This has connecting wires and a plug attached for connection to the supply and connecting wires and a socket for attachment to the equipment. There is also an earth connection, and an individual switch is not required. The device must not result in faulty disconnections as a result of surge currents applied to the protection element or conductor. Switching off does not occur before 10ms after a relatively high series current has been applied to the element. The device may include a spark gap with a protective voltage dependent resistive device such as a varistor disc in series with it. Another device incorporates electrodes separated by an insulating material which releases extinction gas when subjected to heat.</p> |
