Metering & protection

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Calculated residual instantaneous overcurrent50R · SLD / Schematic Calculated residual time-overcurrent51R · SLD / Schematic Capacitive level sensorCAP LVL · Schematic Capacitive VT carrier-coupling boundaryCVCB · Schematic Capacitor voltage transformerCVT / CCVT · SLD / Schematic Checking or interlocking relay3 · SLD / Schematic Circuit-breaker failure protection50BF · SLD / Schematic Combined instrument transformerCT/VT · SLD / Schematic Combined line and phase voltmeter selectorHSW1S92 · Schematic Combined recording wattmeter and varmeterW/var · SLD / Schematic Control power disconnecting device8 · SLD / Schematic Core-balance current transformerCBCT · SLD / Schematic CT multi-ratio tap selection referenceCMTSR · Schematic CT polarity-reference transferCPT · Schematic CT ratio-correction calculation blockCRCB · Schematic CT secondary burden allocation referenceCSBAR · Schematic CT secondary lead-resistance allowanceCSLA · Schematic CT secondary protection-zone crossoverCSPC · Schematic CT secondary shorting-test boundaryCSSB · Schematic CT secondary single-earthing-point referenceCSSR · Schematic CT secondary star-point connectionCSSC · Schematic CT secondary terminal identification boundaryCSTIB · Schematic Current test switch with shorting contactTS · Schematic Current transformerCT · SLD / Schematic Current transformer with primary conductor indicationCT PRI · SLD / Schematic Current transformer with two secondariesCT 2SEC · SLD / Schematic Current unbalance / negative sequence46 · SLD / Schematic Current window monitoring relayI WINDOW · SLD / Schematic Current-measurement merging-unit publisherCMP · Schematic Data communications device16 · SLD / Schematic DC circuit breaker72 · SLD / Schematic DC load-measuring reclosing relay82 · SLD / Schematic DC overcurrent relay76 · SLD / Schematic Dedicated bus-protection CT core interfaceDBCCI · Schematic Dedicated line-protection CT core interfaceDLCCI · Schematic Dedicated transformer-protection CT core interfaceDTCCI · Schematic Definite-time delay qualifier for measuring relayst · Schematic / SLD Density switch or sensor61 · SLD / Schematic Differential protection87 · SLD / Schematic Differential voltmeterDELTA V · SLD / Schematic Differential-current measuring relayI DIFF · SLD / Schematic Digital breaker-command output boundaryDBOB · Schematic Digital secondary test-mode indicationDSTI · Schematic Digital-secondary channel identity cross-referenceDCIC · Schematic Direct transfer-trip receive interfaceDTRI · Schematic Direct transfer-trip send interfaceDTSI · Schematic Direct-operate command interfaceDCI · Schematic Directional ground-overcurrent67G · SLD / Schematic Directional measuring element qualifier→ · Schematic / SLD Directional negative-sequence overcurrent67Q · SLD / Schematic Directional neutral-overcurrent67N · SLD / Schematic Directional overcurrent67 · SLD / Schematic Directional phase-overcurrent67P · SLD / Schematic Directional power32 · SLD / Schematic Directional reactive-power protection32V · SLD / Schematic Directional-comparison blocking interfaceDBI · Schematic Displacement power-factor supervision55D · SLD / Schematic Distance protection21 · SLD / Schematic Disturbance recorderDFR · SLD / Schematic Double frequency meterHz Hz · SLD / Schematic Double voltmeterV V · SLD / Schematic Earth-fault current relayK · Schematic / SLD Earth-fault voltage relayK · Schematic / SLD Electrically operated valve20 · SLD / Schematic Energy meter repeaterkWh · Schematic Energy meter with maximum-demand indicatorkWh/MD · SLD / Schematic Energy meter with pulse transmitterkWh · SLD / Schematic Energy submeterGA · GA / Schematic Equalizer circuit breaker22 · SLD / Schematic Event recorder time-quality flagERTF · Schematic Excess-energy meterkWh> · SLD / Schematic Exciter or DC generator relay53 · SLD / Schematic Fault passage indicatorFPI · SLD / Schematic Field application relay56 · SLD / Schematic Field circuit breaker41 · SLD / Schematic Field ground-fault protection64F · SLD / Schematic Field or loss-of-excitation protection40 · SLD / Schematic Field-changing contactor93 · SLD / Schematic Flame detector28 · SLD / Schematic Flow switch or relay80 · SLD / Schematic Four-point current measurement selectorHSW1S95 · Schematic Frequency meterHz · SLD / Schematic Frequency monitoring relayf MON · SLD / Schematic Frequency protection81 · SLD / Schematic GalvanometerG · Schematic Generator current-unbalance protection46G · SLD / Schematic Generator differential protection87G · SLD / Schematic Generator-voltage synchronising input interfaceGSII · Schematic GOOSE interlock publisher interfaceGIPI · Schematic GOOSE interlock subscriber interfaceGISI · Schematic GOOSE supervision timeout interfaceGSTI · Schematic GOOSE trip publisher interfaceGTPI · Schematic GOOSE trip subscriber interfaceGTSI · Schematic Governor65 · SLD / Schematic Ground detector protection64 · SLD / Schematic Ground distance protection21G · SLD / Schematic Hall-effect current sensorHALL I · Schematic Impulse tachometric transducerHIN1B12 · Schematic Incomplete-sequence relay48 · SLD / Schematic Indicating instrument general symbol* · SLD / Schematic