GE Multilin F60 Feeder Protection System 5-1055 SETTINGS 5.4 SYSTEM SETUP5Figure 5–41: PMU RECORDING• PMU 1 RECORDING RATE: This setting specifies the recording rate for the record content. Not all recording rates areapplicable to either 50 or 60 Hz systems (for example, recording at 25 phasors a second in a 60 Hz system). The relaysupports decimation by integer number of phasors from the nominal system frequency. If the rate of 25 is selected forthe 60 Hz system, the relay would decimate the rate of 60 phasors a second by round (60 / 25) = 2; that is, it wouldrecord at 60 / 2 = 30 phasors a second.• PMU 1 NO OF TIMED RECORDS: This setting specifies how many timed records are available for a given logicalPMU. The length of each record equals available memory divided by the content size and number of records. Thehigher the number of records, the shorter each record. The relay supports a maximum of 128 records.• PMU 1 TRIGGER MODE: This setting specifies what happens when the recorder uses its entire available memorystorage. If set to “Automatic Overwrite”, the last record is erased to facilitate new recording, when triggered.If set to “Protected”, the recorder stops creating new records when the entire memory is used up by the old un-clearedrecords. Refer to chapter 7 for more information on clearing PMU records.The following set of figures illustrate the concept of memory management via the PMU 1 TRIGGER MODE setting.Figure 5–42: “AUTOMATIC OVERWRITE” MODEFigure 5–43: “PROTECTED” MODETRIGGERREC847709A2.CDRRecord1Record2Record3FreememoryFreememory Other logical PMUsMemory available for the logical PMUTotal memory for all logical PMUsRecord1Record2Record3FreememoryRecord4 Other PMUslogicalRecord1Record2Record3 Other PMUslogicalRecord4Record5Record6Record2Record3 Other PMUslogicalRecord4Record5847705A1.CDR847706A1.CDRRecord1Record2Record3FreememoryFreememory Other PMUslogicalMemory available for the logical PMUTotal memory for all logical PMUsRecord1Record2Record3FreememoryRecord4 Other logical PMUsRecord1Record2Record3 Other PMUslogicalRecord4Record5No further recording after all allocated memory is used
