SIPROTEC 4 7SJ63 Multifunction Protection Relay - Siemens

5 Overcurrent Protection / 7SJ63FunctionsMeasured valuesThe r.m.s. values are calculated from the acquiredcurrent and voltage along with thepower factor, frequency, active and reactivepower. The following functions are availablefor measured value processing:• Currents I L1 , I L2 , I L3 , I E , I EE (67Ns)• Voltages V L1 , V L2 , V L3 , V L1L2 , V L2L3 , V L3L1• Symmetrical componentsI 1 , I 2 ,3I 0 ; V 1 , V 2 , V 0• Power Watts, Vars, VA/P, Q, S(P, Q: total and phase-selective)• Power factor (cos ϕ)(total and phase-selective)• Frequency• Energy ± kWh, ± kVarh, forward andreverse power flow• Mean as well as minimum and maximumcurrent and voltage values• Operating hours counter• Mean operating temperature of overloadfunction• Limit value monitoringLimit values are monitored using programmablelogicintheCFC.Commandscan be derived from this limit value indication.• Zero suppressionIn a certain range of very low measuredvalues, the value is set to zero to suppressinterference.Metered valuesFor internal metering, the unit can calculatean energy metered value from the measuredcurrent and voltage values. If an external meterwith a metering pulse output is available,the SIPROTEC 4 unit can obtain and processmetering pulses via an indication input.The metered values can be displayed andpassed on to a control center as an accumulationwith reset. A distinction is made betweenforward, reverse, active and reactiveenergy.Measuring transducers• Characteristic with kneeFor measuring transducers it sometimesmakes sense to extend a small range of theinput value, e.g. for the frequency that isonly relevant in the range 45 to 55, 55 to65 Hz. This can be achieved by using aknee characteristic.• Live-zero monitoring4 - 20 mA circuits are monitored foropen-circuit detection.LSP2078-afp.eps5Switchgear cubiclesfor high/medium voltageAll units are designed specifically to meetthe requirements of high/medium-voltageapplications.In general, no separate measuring instruments(e.g. for current, voltage, frequencymeasuring transducer ...) or additionalcontrol components are necessary.Fig. 5/121NX PLUS panel (gas-insulated)Siemens SIP · 20065/127