OVERVOLTAGE PROTECTION DEVICE WITH IMPROVED FOLLOW CURRENT INTERRUPTING CAPACITY

摘要

The invention relates to a device (1) which is used to protect electrical equipment against transient overvoltages, comprising (i) a spark gap having an intrinsic follow current interrupting capacity and (ii) an element (5) for improving the follow current interrupting power, which co-operates with the spark gap (2) such that the resulting follow current interrupting capacity of the protective device (1) is essentially greater than the aforementioned intrinsic capacity. The invention is characterised in that, when the equipment has a suspected short-circuit current that exceeds the intrinsic interrupting capacity of the spark gap (2), the improving element (5) comprises a means (6) for limiting the intensity of the electric current that can pass through the spark gap (2), said limiting means (6) being specifically designed and mounted in relation to the spark gap (2) in order to limit the intensity of the follow current, such that the follow current can be interrupted thanks to the intrinsic follow current interrupting capacity of the spark gap (2). The invention is suitable for overvoltage protection devices.