5-54 L60 Line Phase Comparison System GE Multilin5.2 PRODUCT SETUP 5 SETTINGS5The FAULT REP 1 SYSTEM Z0 MAG and FAULT REP 1 SYSTEM Z0 ANGLE settings are used only when the VT SUBSTITUTION set-ting value is “I0”. The magnitude is to be entered in secondary ohms. This impedance is an average system equivalentbehind the relay. It can be calculated as zero-sequence Thevenin impedance at the local bus with the protected line/feederdisconnected. The method is accurate only if this setting matches perfectly the actual system impedance during the fault. Ifthe system exhibits too much variability, this approach is questionable and the fault location results for single-line-to-groundfaults shall be trusted with accordingly. It should be kept in mind that grounding points in vicinity of the installation impactthe system zero-sequence impedance (grounded loads, reactors, zig-zag transformers, shunt capacitor banks, etc.).5.2.9 OSCILLOGRAPHYa) MAIN MENUPATH: SETTINGS PRODUCT SETUP OSCILLOGRAPHYOscillography records contain waveforms captured at the sampling rate as well as other relay data at the point of trigger.Oscillography records are triggered by a programmable FlexLogic operand. Multiple oscillography records may be capturedsimultaneously.The NUMBER OF RECORDS is selectable, but the number of cycles captured in a single record varies considerably based onother factors such as sample rate and the number of operational modules. There is a fixed amount of data storage for oscil-lography; the more data captured, the less the number of cycles captured per record. See the ACTUAL VALUES RECORDS OSCILLOGRAPHY menu to view the number of cycles captured per record. The following table provides sam-ple configurations with corresponding cycles/record. The minimum number of oscillographic records is three.A new record may automatically overwrite an older record if TRIGGER MODE is set to “Automatic Overwrite”. OSCILLOGRAPHYNUMBER OF RECORDS:15Range: 1 to 64 in steps of 1MESSAGE TRIGGER MODE:Automatic OverwriteRange: Automatic Overwrite, ProtectedMESSAGE TRIGGER POSITION:50%Range: 0 to 100% in steps of 1MESSAGE TRIGGER SOURCE:OffRange: FlexLogic operandMESSAGE AC INPUT WAVEFORMS:16 samples/cycleRange: Off; 8, 16, 32, 64 samples/cycleMESSAGE DIGITAL CHANNELSMESSAGE ANALOG CHANNELSTable 5–3: OSCILLOGRAPHY CYCLES/RECORD EXAMPLERECORDS CT/VTS SAMPLERATE DIGITALS ANALOGS CYCLES/RECORD3 1 8 0 0 146633 1 16 16 0 69458 1 16 16 0 34728 1 16 16 4 28688 2 16 16 4 16918 2 16 63 16 12218 2 32 63 16 7498 2 64 63 16 42232 2 64 63 16 124
