Siemens Argus 7SR21 Technical Manual

Also see for Argus 7SR21: Installation guide Manual Manual Manual Manual

Contents

7SR210 & 7SR220 Description of OperationUnrestricted Page 66 of 94 ©2018 Siemens Protection Devices Limited4.9 SynchronisingThe optional Synchronising function is used to check that the voltage conditions, measured by the voltagetransformers on either side of the open circuit breaker, indicate that it is safe to close without risk of damage tothe circuit breaker of disturbance to the system. The timing of closure, for charging lines which are dead followingfault clearance, is controlled to co-ordinate with other devices.The window of time in which voltage conditions must be met is applied as a setting or can be disabled such thatan indefinite period is allowed.4.9.1 Reclosure ModesThe Synchronising element can be set to allow the autoreclose sequence to proceed for various system voltageconditions. The voltage conditions selected must be met within the Synch Close Window time if this is Enabled,this time can be set and starts at the end of the deadtime for autoreclose or the receipt of a Close CB command.The voltage applied to the V4 input is considered to be the BUSBAR voltage and the voltages applied to inputsV1,V2 & V3 are the LINE voltage.79 Dead Bar Charge, when set to Enabled, allows AR to proceed when the Line voltage is live and the Busbar isdead.Manual Close DBC, when set to Enabled, allows MC to proceed when the Line voltage is live and the Busbar isdead.79 Dead Line Charge, when set to Enabled, allows AR to proceed when the Busbar voltage is live and the Line isdead.Manual Close DLC, when set to Enabled, allows MC to proceed when the Busbar voltage is live and the Line isdead.79 Dead Line & Dead Bar Close, when set to Enabled, allows AR to proceed when the Line voltage and theBusbar voltage are dead.Manual Close DLDB, when set to Enabled, allows MC to proceed when the Line voltage and the Busbar voltageare dead.79 Check Sync Close, when set to Enabled, allows AR to proceed when both the Line and Busbar areconsidered live AND other synchronising requirements are met.Manual Close CS, when set to Enabled, allows MC to proceed when both the Line and Busbar are consideredlive AND other synchronising requirements are met.79 Unconditional Close, when set to Enabled, allows AR to proceed regardless of the voltage condition of theBus or Line.Unconditional Manual Close, when set to Enabled, allows MC to proceed regardless of the voltage condition ofthe Bus or Line.Separate Enable/Disable settings are thus provided for each option for Autoreclose and Manual Close.4.9.2 Charge DelaysSeparate autoreclose delay settings are provided for Dead Line Charge and Dead Bus Charge closure by the 79DLC Delay and 79 DBC Delay settings. These are applied after the autoreclose Dead Time when voltageconditions are checked and met, at the Close Inhibit stage of the sequence. This feature effectively allows thedead time to be set differently for faults on each side of the recloser.4.9.3 Voltage monitoring elementsThe single phase voltage source used for synchronising can be selected as any phase-to-phase or phase-to-earthvoltage for flexibility. The voltage is compared to the corresponding voltage from the three-phase arrangement onthe other side of the circuit-breaker. Voltage settings are set as a percentage of the nominal voltage specified inthe CT/VT Config menu.