{"product_id":"abb-spcd-3c21-biased-single-phase-differential-relay-module-for-phase-l1","title":"ABB SPCD 3C21 Biased Single-Phase Differential Relay Module for Phase L1","description":"\u003ch3\u003eDescription\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eABB SPCD 3C21\u003c\/strong\u003e is a biased single-phase differential relay module designed for phase L1 transformer differential protection.\u003c\/p\u003e\n\u003cp\u003eThe module measures the high-voltage and low-voltage side currents of the protected transformer. It calculates differential and stabilizing currents for protection decisions.\u003c\/p\u003e\n\u003cp\u003eTransformer vector-group matching is configured through front-panel selector switches. Separate correction settings compensate for current-transformer ratios on the HV and LV sides.\u003c\/p\u003e\n\u003cp\u003eThe biased differential stage provides adjustable basic starting and stabilizing settings. An additional instantaneous high-set stage provides operation for high differential currents.\u003c\/p\u003e\n\u003cp\u003eSecond-harmonic restraint automatically blocks the differential stage when transformer inrush current is detected. The module also supports blocking inputs, trip outputs, event recording, self-supervision, and SPA bus communication.\u003c\/p\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eBiased single-phase differential protection\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eDesigned for transformer phase L1\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHV and LV current measurement\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eDifferential current measurement\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eStabilizing current calculation\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eTransformer vector-group matching\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eIndependent CT ratio correction for HV and LV sides\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eAdjustable basic differential starting value\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eAdjustable starting ratio\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eInstantaneous high-set differential stage\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSecond-harmonic inrush restraint\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eExternal blocking input\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eBlocking signal output\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eLatched trip option\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eFront-panel measured-value display\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSelf-supervision alarm\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eRecorded trip and disturbance information\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSPA bus communication\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eApplications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003ePower transformer differential protection\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eThree-phase transformer protection using one module per phase\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHV\/LV current comparison\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eTransformer inrush discrimination\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSubstation protection systems\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSPACOM protection and control systems\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eReplacement of installed SPCD 3C21 relay modules\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eABB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eSPCD 3C21\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eDifferential Relay Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProtection Principle\u003c\/td\u003e\n\u003ctd\u003eBiased single-phase differential\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProtected Phase\u003c\/td\u003e\n\u003ctd\u003eL1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAssociated Phase L2 Module\u003c\/td\u003e\n\u003ctd\u003eSPCD 3C22\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAssociated Phase L3 Module\u003c\/td\u003e\n\u003ctd\u003eSPCD 3C23\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMain Measurements\u003c\/td\u003e\n\u003ctd\u003eHV current, LV current, differential current\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication\u003c\/td\u003e\n\u003ctd\u003eSPA bus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSelf-Supervision\u003c\/td\u003e\n\u003ctd\u003eIntegrated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eBiased Differential Stage\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBasic Starting Value p\u003c\/td\u003e\n\u003ctd\u003e20 to 50% of In\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStarting Ratio s\u003c\/td\u003e\n\u003ctd\u003e10 to 50%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHV-side CT Ratio Correction I1\/In\u003c\/td\u003e\n\u003ctd\u003e0.5 to 1.0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLV-side CT Ratio Correction I2\/In\u003c\/td\u003e\n\u003ctd\u003e0.5 to 1.0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecond-Harmonic Restraint Threshold\u003c\/td\u003e\n\u003ctd\u003e10 to 20% x Id\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Accuracy\u003c\/td\u003e\n\u003ctd\u003e±5% of set value\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Time\u003c\/td\u003e\n\u003ctd\u003e20 to 50 ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eHigh-Set Differential Stage\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eStarting Current Id\u0026gt;\u0026gt;\u003c\/td\u003e\n\u003ctd\u003e20 to 30 x In\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Accuracy\u003c\/td\u003e\n\u003ctd\u003e±5% of maximum setting-range value\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Time\u003c\/td\u003e\n\u003ctd\u003e10 to 20 ms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eProtection Functions\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eFunction\u003c\/th\u003e\n\u003cth\u003eDescription\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBiased Differential Protection\u003c\/td\u003e\n\u003ctd\u003eOperates from differential current with stabilizing-current restraint\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHigh-Set Stage\u003c\/td\u003e\n\u003ctd\u003eFast operation at high differential current\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecond-Harmonic Blocking\u003c\/td\u003e\n\u003ctd\u003eRestrains operation during transformer magnetizing inrush\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExternal Blocking\u003c\/td\u003e\n\u003ctd\u003eBS IN can block the differential stage\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlocking Output\u003c\/td\u003e\n\u003ctd\u003eBS OUT provides blocking to associated phase modules\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTrip Signal\u003c\/td\u003e\n\u003ctd\u003eTS output provides trip indication\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLatching\u003c\/td\u003e\n\u003ctd\u003eSelectable through switch SG1\/7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSelf-Supervision\u003c\/td\u003e\n\u003ctd\u003eInternal relay fault monitoring and alarm indication\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eFront-Panel Settings\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSetting\u003c\/th\u003e\n\u003cth\u003eRange \/ Function\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ep\u003c\/td\u003e\n\u003ctd\u003eBasic differential starting value, 20 to 50% of In\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003es\u003c\/td\u003e\n\u003ctd\u003eStarting ratio, 10 to 50%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eI1\/In\u003c\/td\u003e\n\u003ctd\u003eHV-side CT ratio correction, 0.5 to 1.0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eI2\/In\u003c\/td\u003e\n\u003ctd\u003eLV-side CT ratio correction, 0.5 to 1.0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSG1\u003c\/td\u003e\n\u003ctd\u003eVector-group matching, latching, blocking mode, and related selections\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSTEP\u003c\/td\u003e\n\u003ctd\u003eDisplay navigation and setting access\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRESET\u003c\/td\u003e\n\u003ctd\u003eReset of indications and recorded information\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eMeasured Data\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eIndicator\u003c\/th\u003e\n\u003cth\u003eMeasured Value\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eI1\u003c\/td\u003e\n\u003ctd\u003eHV-side load current as a multiple of relay rated current\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eId\u003c\/td\u003e\n\u003ctd\u003eDifferential current as a multiple of relay rated current\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eI2\u003c\/td\u003e\n\u003ctd\u003eLV-side load current as a multiple of relay rated current\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eRecorded Information\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eRegister\u003c\/th\u003e\n\u003cth\u003eRecorded Data\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003ctd\u003eDifferential current at the moment of tripping\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003ctd\u003eStabilizing current at the moment of tripping\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e3\u003c\/td\u003e\n\u003ctd\u003eMaximum stabilizing current after latest reset\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003ctd\u003eMaximum second-harmonic current after latest reset\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e5\u003c\/td\u003e\n\u003ctd\u003eFilter calibration register\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e0\u003c\/td\u003e\n\u003ctd\u003eBlocking-mode status\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eA\u003c\/td\u003e\n\u003ctd\u003eModule communication address\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eCommunication Data\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication System\u003c\/td\u003e\n\u003ctd\u003eSPA bus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModule Address\u003c\/td\u003e\n\u003ctd\u003e1 to 254\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eData Transfer Rate\u003c\/td\u003e\n\u003ctd\u003e4800 or 9600 baud\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEvent Reporting\u003c\/td\u003e\n\u003ctd\u003eSupported\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRemote Reading\u003c\/td\u003e\n\u003ctd\u003eSupported\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRemote Setting\u003c\/td\u003e\n\u003ctd\u003eSupported with password\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePassword Range\u003c\/td\u003e\n\u003ctd\u003e1 to 999\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eEvent Codes\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eCode\u003c\/th\u003e\n\u003cth\u003eEvent\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eE1\u003c\/td\u003e\n\u003ctd\u003eHarmonics blocking\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eE2\u003c\/td\u003e\n\u003ctd\u003eHarmonics blocking reset\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eE3\u003c\/td\u003e\n\u003ctd\u003eTripping\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eE4\u003c\/td\u003e\n\u003ctd\u003eTripping reset\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eE50\u003c\/td\u003e\n\u003ctd\u003eRestarting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eE51\u003c\/td\u003e\n\u003ctd\u003eEvent-register overflow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eE52\u003c\/td\u003e\n\u003ctd\u003eTemporary data communication disturbance\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eE53\u003c\/td\u003e\n\u003ctd\u003eNo response from module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eE54\u003c\/td\u003e\n\u003ctd\u003eModule responds again\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eTransformer Vector-Group Matching\u003c\/h3\u003e\n\u003cp\u003eThe SPCD 3C21 provides selectable transformer vector-group matching through switchgroup \u003cstrong\u003eSG1\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eThe relay compensates for phase displacement between HV and LV currents without requiring external interposing transformers for the supported configurations.\u003c\/p\u003e\n\u003cp\u003eThe setting must match the actual transformer vector group and CT connection arrangement.\u003c\/p\u003e\n\u003ch3\u003eInstallation \u0026amp; Commissioning\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eVerify that \u003cstrong\u003eSPCD 3C21\u003c\/strong\u003e is used for phase L1.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eConfirm SPCD 3C22 and SPCD 3C23 assignments where a three-phase scheme is used.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eRecord all SG1 selector positions before replacing an existing module.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eConfirm transformer vector group and CT connection before setting SG1.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSet HV and LV CT ratio corrections according to the installed current transformers.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eVerify the basic starting value, starting ratio, harmonic restraint, and high-set settings.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCheck BS IN, BS OUT, TS, and self-supervision functions before service.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eVerify SPA communication address and baud rate where remote communication is used.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eReplacement Notes\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eMatch the exact \u003cstrong\u003eSPCD 3C21\u003c\/strong\u003e phase designation during replacement.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSPCD 3C21, SPCD 3C22, and SPCD 3C23 are assigned to phases L1, L2, and L3 respectively.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003ePreserve SG1 vector-group and blocking selections from the original installation.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003ePreserve protection settings and SPA communication parameters before removing the existing relay.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ABB","offers":[{"title":"Default Title","offer_id":53755718009195,"sku":"SPCD3C21","price":99.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0953\/3227\/0443\/files\/SPCD-3C21_003_1200x1200_b3d8f7f4-c752-452f-a5e0-bd606b20e95a.jpg?v=1787403447","url":"https:\/\/www.plcprotech.com\/products\/abb-spcd-3c21-biased-single-phase-differential-relay-module-for-phase-l1","provider":"PLC ProTech Ltd.","version":"1.0","type":"link"}