Toshiba GR200 Series Instruction Manual

Also see for GRB200: Instruction manual

6F2S1931 (0.20)Centralized GRB200(Soft: 030, 031, 032, 033, 034)- 22 -(ii) Discriminating-zone-protection (DIFZA to DIFZF)In discriminating-zone-protection, the input signals are currents and the disconnector-open/close-status (DS) signals from feeder bays, transformer bays, bus-sections, and bus-couplers that correspond to the protection zone. The Discriminating-zone-protection issues tripcommands to all circuit breakers (CBs) within its protection-zone.The protection-zone covered by the discriminating-zone-protection depends upon the bus-bar configuration; the boundary of each discriminating-zone-protection is determined usingthe DS signals. The user can utilize a replica setting which identifies which circuit connects towhich protection-zone; and the boundary of the zone-protection mimics the changes in bus-barconfiguration throughout the operation of the bus-bar. Up to six protection-zones are availableusing the relevant input currents and DS signals.Figure 2.1-5 illustrates input-currents and DS contacts received at respective CHs. Theinput-currents are transferred to the DIFZA and DIFZB elements by the DS signal; the input-currents are also transferred to the the DIFCH element.