ABB SPAJ 141 C-AA RS 611 007-AA PROTECTION RELAY

About ABB SPAJ 141 C-AA RS 611 007-AA PROTECTION RELAY

ABB SPAJ 141 C-AA RS 611 007-AA PROTECTION RELAY

The combined overcurrent and earth-fault relayis a secondary relay device to be connected tothe current transformers of the feeder to beprotected. The three-phase overcurrent unit andthe non-directional earth-fault unit continuously measure the phase currents and the neutral current of the protected feeder. In fault situations these units initiate external auto-reclosefunctions or trip the circuit-breaker, dependingon the selected protective scheme.When a phase current exceeds the starting valueof the low-set overcurrent unit, the unit starts, simultaneously starting the corresponding timingcircuit. When the set operating time has elapsed,a circuit-breaker tripping command is delivered.Correspondingly, the high-set stage of the overcurrent unit starts when its starting value is exceeded, starting its timing circuit and performinga tripping when the set time has elapsed.The low-set stage of the non-directional earthfault unit operates in the same way. Dependingon the protective scheme it either signals, performs a tripping or initiates a function of anexternal auto-reclose relay. The input circuitcomprises a low-pass filter, which reduces theamount of harmonics in the neutral currentbefore the signal is measured.The low-set stage of the overcurrent unit may begiven definite time or inverse definite minimumtime (IDMT) characteristics. When the IDMTcharacteristic is to be chosen six curve types areavailable in the relay. Four of the curves typescomply with BS 142 and IEC 60255 and arenamed normal inverse, very inverse, extremelyinverse and long-time inverse. The two additionalcurves are named the RI curve and the RXIDGcurve. The low-set stage of the earth-fault unit isoperating on a definite time basis.By appropriate programming of the trippingrelay matrix, the starting signals of the overcurrent and non-directional earth-fault modules arereceived as contact functions. This contact information is used e.g. for the blocking of cooperating protective relays located upstreams.The relay comprises one external logic controlinput, which is actuated by a control signal ofthe auxiliary voltage level. The influence on therelay by the control input is determined by programming switches in the measuring module.The control input can be used either for blocking one or more of the protective stages, for resetting a latched output relay in the manual reset mode or for selecting a new group of relaysettings by remote control.

Versatile Protection for Distribution Networks

Engineered for demanding electrical environments, the SPAJ 141 C-AA relay delivers reliable protection against overcurrent, earth faults, and phase issues. Its advanced microprocessor design enables accurate fault detection and swift trip responses, minimizing downtime and safeguarding network performance. Built to withstand a wide range of operating conditions, this relay is suited for use in both industrial and utility settings.


Intuitive Monitoring and Control Features

With a clear LCD display and LED indications, users receive instant fault, trip, and event feedback. Manual or automatic reset options and adjustable time delays ensure flexible operation tailored to system needs. Integration with RS-485 or optional RS-232 communication enhances remote monitoring and control capabilities, streamlining maintenance and diagnostics.


Robust Design and Safety Compliance

The relay meets stringent IEC 60255 standards and holds CE certification, affirming its safety and quality. Enclosure protection ratings, high insulation resistance, and durable mechanical construction (over 10 million operations) ensure long service life. Modular panel mount design and screw-type terminals facilitate easy installation and maintenance.