Toshiba GR200 Series Instruction Manual

Also see for GRB200: Instruction manual

6F2S1931 (0.20)Centralized GRB200(Soft: 030, 031, 032, 033, 034)- 32 -Figure 2.1-11 shows each CH generates trip and transfer-trip signals. The DIF relay canuse Fail-safe signal for the decision of DIF trip issuing; the Fail-Safe function can monitor thesystem voltages and issues a permissive signal on the detection of a fault. Note that a faultwill be detected when either an under voltage occurs (phase-phase/phase-neutral faults) or anover voltage occurs in the residual monitored voltage (phase-earth fault).To augment to generate the trip commands, PLC connection points are provided inrespective zones. For instance of the zone A, the PLC connection point “ADD.DIF.TP-ZA” isprovided in front of the issuing stage of the signal “DIF.OPT-ZAX”. Accordingly, if the tripsignal “DIF.OPT-ZAX” should be generated upon occurrence of the trip command “DIF.OPT-ZB”, it is possible to issue the one when the user programs to connect the trip command“DIF.OPT-ZA” with the PLC connection point “ADD.DIF.TP-ZA”.For the operation of the “check zone and discriminating zone protection”, it is requiredthat there are no failures in both CT circuits and for differential current monitoring (For moreinformation of CTF and IDSV, see section 2.1.8 and 2.1.9).(ii) DIF settingTable 2.1-3 shows the setting elements necessary for DIF together with the respective settingranges.Table 2.1-3 DIF setting switchSetting items Mode / range Unit Contents DefaultDIF-EN Off – Blocking DIF protection OnOn Enabling DIF protectionDIFCH-I 10 – 20,000 A Minimum operating current in DIFCH 2,000DIFCH-Slope 0 – 90 % Id-Ir characteristic percentage slope inDIFCH 30CTSCCH-EN Off – Blocking CTSC in DIFCH OnOn Enabling CTSC in DIFCHDIFDZ-I 10 – 20,000 A Minimum operating current inDIFZA,DIFZB, and others 2,000DIFDZ-Slope 0 – 90 % Id-Ir characteristic percentage slope inDIFZA,DIFZB, and others 30CTSCDZ-EN Off – Blocking CTSC in DIFDZ OnOn Enabling CTSC in DIFDZDIFTP-FORMCH&DZ–Operation in both Check-zone andDiscriminating-zone CH&DZCH Operation in Check-zone onlyDZ Operation in Discriminating-zone onlyDIFTP-FS Off – DIF trip issued without FS operation OffOn DIF trip issued with FS operationNote: For the DIF operation, the user should set values concerning to ‘CT primarycurrents’ and ‘CT ratios’ on the VCT. For more information about the VCTsettings, see ChapterTechnical description: Transformer module for AC analog