Protection and disconnection module for two=wire circuits - uses three-terminal overvoltage detector to hold contacts between input and output closed with sockets for test probes built into support

摘要

The module consists of an insulating base and a pair of connecte connecting pins for each circuit (2,3 and 4,5) which are connected to a protection device (18). The centre of the protective device is joined by an open ring clamp (25) mounted on a metal strip (23) which is grounded. The connecting pins are connected to a pair of flexible metal strips (8,9) and to a rigid pair (12,13) which are separated by gaps (14,15) between their ends. When the protective device is inserted the flexible strips are put in contact with the ends of the rigid strips. The flexible strips have dished ends to hold the ends of the protective device. There are two groups of three sockets in the insulating support connected to the pins and to ground for test and measurement probes to be used with or without the device in position. The modules are mounted in groups which can be linked end to end by the earth strip.