ABB REX 521 Technical Reference Manual, Standard Configurations

Also see for REX 521: Operator's manual Technical Reference Manual, General Technical Reference Manual, General Operating guide Technical Reference Manual, Standard Configurations

Contents

ABB REX 521 Technical Reference Manual, Standard Configurations Manual pdf 123 page image

1MRS 751802-MUM Protection RelayTechnical Reference Manual, Standard ConfigurationsREX 521123overcurrent start signal from the 3I>> stage is routed via Start 1 and then connectedto the signal output 2, SO2. The checksum in this application example for Start 1 is2.9.2.4.3. Earth-fault stage Io>>> to trip the breaker on the HV side of thetransformerThe trip signal from the earth-fault instantaneous stage can be routed to an outputrelay to trip the breaker on the HV side of the transformer. To use the trip signal fromthe earth-fault function, the signal has to be routed viaMain menu\Configuration\Output SWGRP\Trip 2 or \Trip 3.When the trip signal has been routed, the output relay has to be selected inMain menu\Configuration\Output Signals.In this example, the trip signal of the earth-fault stage Io>>> is routed viaTrip 2 and then connected to the power output 2, PO2. The checksum in thisapplication example for Trip 2 is 32.9.2.4.4. Circuit-breaker failure protectionAll of the protection functions in the standard configuration B01 provide a delayedtrip signal CBFP after the trip signal unless the fault has not disappeared during theset CBFP time delay. In the circuit-breaker failure protection, the CBFP output canbe used for operating an upstream circuit breaker.The settings for the breaker failure are set separately for each protection function.For example, to set the CBFP time for 3I>>, go toMain menu\Protection\3I>>\Control setting, where it is possibleto set the “CBFP time” from 100 ms to 1000 ms. The control parameter “Trip pulse”sets the width of the trip output signal, but also of the CBFP output signal.The CBFP signals from the protection functions are routed to the output signals viathe output switchgroups. These settings can be found inMain menu\Configuration\Output SWGRP\CBFP. When the three-stageovercurrent and the two-stage earth-fault protection are selected the checksum forCBFP is 31.The CBFP signal is then connected to any of the output relays, viaMain menu\Configuration\Output Signals\. In this example, thecircuit-breaker failure signal is connected to the power output 1, PO1.9.2.4.5. Disturbance recorderThe disturbance recorder (DREC) can be found inMain menu\Measurement\DREC\. All of the measured current signals as wellas all of the start signals from the protection functions are connected to the DRECin the B01 standard configuration.The recording can be triggered by any of the alternatives listed below:• triggering on the rising or falling edge of the protective start signals• triggering on current measurement• manual triggering via the HMI or with the external input signal• triggering via communication parameter