GB355013A - Improvements in or relating to protective connections with excess current and direction relays - Google Patents

Abstract

355,013. Protective cut-out arrangements. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. Aug. 8, 1930, No. 23824. Convention date, Aug. 10, 1929. [Class 38 (v).] Relay groups I, II, disposed one on each side of the section or apparatus to be protected, are interconnected by auxiliary lines L over which current normally flows from the left-hand + pole, through closed contact H<12>, relay coils H<13> H<23> closed contacts H<22> and back to the - pole. On a fault occurring in the section, one or other or both overload relays A<10>, A<20> close their contacts and energize relay coil or coils H<10>, H<20> and graded time relay or relays Z<1>, Z<2>. The relay coils H<10>, H<20> break the circuit at H<12>, H<22> of the lines L, thereby disengaging the coils H<13>, H<23> and giving a visual signal at 13, 23. The relays Z<1>, Z<2> close their contacts 14, 24 to energize the coils of energydirectional relays R<1>, R<2> which close their contacts R<11>, R<12> and R<21>, R22 to energize again the coils H<13>, H<23>, which energize the trip-coils 15, 25 to cut out the section or apparatus. If the section is fed on one side only, say the left side, the relays of group II remain idle, but those of group I operate as described. The circuit of the coils H<13>, H<23> is however made over the closed contacts H<22> instead of contacts R<21>, R<22>. In the event of a straight-through fault, the relays R<1>, R<2> operate in the same direction so that contacts R<11>, R<12> and R<21>, R<23>, for instance, close and tripping is not effected. Tripping will, however, be effected after a time-delay dependent on the distance of the fault, and assuming the latter has not been disconnected elsewhere, by the overload relays operating in conjunction with the time-relays which close their contacts 16, 25 to energize the tripcoils 15, 25. The signals 13, 23 serve also to indicate a fault in the lines L.