Abstract: A contact arrangement for a Pre-Insertion Resistor (PIR) wherein a control rod is arranged to move a movable contact, against the force of a biasing member, into temporary connection with a PIR. The control rod comprises a tulip with a plurality of resilient fingers and having a first diameter where it is able to mechanically couple to a latching ring on the movable contact, and a second diameter where the tulip is deformed with the fingers deflected inwards, once the resistance to movement exceeds a predetermined value, wherein the latching ring is able to pass over the tulip to decouple the movable contact from the control rod. The contact arrangement is particularly suited for a PIR arranged for connection in parallel to the interrupter of a gas-insulated switchgear (GIS) circuit breaker.

Abstract: The invention concerns a contact arrangement (50) for a Pre-Insertion Resistor (PIR) wherein a control rod (20) is arranged to move a movable contact (30), against the force of a biasing member (18), into temporary connection with a PIR. The control rod (20) comprises a tulip (21) with a plurality of resilient fingers (24) and having a first diameter where it is able to mechanically couple to a latching ring (31) on the movable contact (30), and a second diameter where the tulip (21) is deformed with the fingers (24) deflected inwards, once the resistance to movement exceeds a predetermined value, wherein the latching ring (31) is able to pass over the tulip (21) to decouple the movable contact (30) from the control rod (20). The contact arrangement (50) is particularly suited for a PIR arranged for connection in parallel to the interrupter of a gas-insulated switchgear (GIS) circuit breaker.