REX 521 Brochure - ABB Oy Distribution Automation - #2

The REX 521 relay incorporates a large number of supervision functions for con­stant monitoring ofthe relay's operational preparedness. On the relay input side both voltage and current measuring circuits are continuously supervised. On the relay out­put side the trip circuits, including the CB trip coils, are constantly supervised for loss of control voltage or trip circuit dis­continuity. Further, the condition of the circuit breaker can be monitored for me­chanical wear on the main contact. The auxiliary supply of the relay and the internal relay voltages are supervised by the relay's integrated self-supervision system, which also incorporates watchdog functions su­pervising the operation of the relay.

The REX 521 relays are fully integrated into ABB's distribution automation and network management systems. The support for all major communication protocols and stan­dards, including the new IEC 60850 stan­dard, makes the relay a perfect fit for your network control and management system. In addition to protection, REX offers exten­sive measurements including phase cur­rents, neutral current, line voltages, residual voltage, system frequency, power factor, active and reactive power, total harmonic distortion (THD) and power quality. Any doubtful event in the power system can be recorded by the built-in high-sampling-frequency disturbance recorder for subse­quent disturbance or fault analysis.

3-phase non-directional overcurrent protection, 3 stages

3-phase directional overcurrent protection, 2 stages •3I< 37

3-phase undercurrent protection

Non-directional earth-fault protection, 3 stages

Directional earth-fault protection, 3 stages

Residual overvoltage protection, 3 stages

• 3U>, 3U>> 59 3-phase overvoltage protection, 2 stages

• 3U<, 3U<< 27 3-phase undervoltage protection, 2 stages •3I_2f> 68 3-phase transformer inrush and motor start-up current

detector

• AI> 46

Phase discontinuity protection

3-phase thermal overload protection

Auto-reclosefunction (5 shots)

• f</f>, df/dt 81U7810 Underfrequency/overfrequency protection

• SYNC 25 Synchro-check/voltage-checkfunction

Three-phase thermal overload protection for devices •I_s²t n< 48/14/66

Three-phase motor start-up supervision •3I ^,3I^ 46R

Phase reversal protection

Negative phase sequence protection with two stages •U₁<, U₂>, U₁> 27/47/59

Phase sequence voltage protection

Fuse failure protection

Circuit-breaker failure protection Included into every protection function

I<->0 CB1 Circuit breaker control & indication

with adjustable closing delay I<->0IND1-3 Objectlndication I<->0 POS Logic control position selection ALARM1-8 AlarmLEDs1-8

CB wear Circuit-breaker condition monitoring

TCS1 Trip-circuitsupervision

MCS 3I Energizing current circuit supervision

MCS 3U Energizing current circuit supervision

TIME1 Operation time counter

3I 3-phase current measurement

I₀ Neutral current measurement

U₀ Residual voltage measurement

3U 3-phasevoltagemeasurement

f System frequency measurement

E,P,Q,pf 3-phase power and energy (ncl. cos (p) DREC Transient disturbance recorder

AI1 Analog measuring function

THD Current and voltage distortion

measurements(1-13^th harmonics) PQ3Inf Current waveform distortion

measurement

PQ3Unf Voltagewaveformdistortion

measurement

• Non-volatile memory

• Ninedigital inputs

• Four power outputs

• Two signalling outputs

• User-configurable Alarm LEDs

• Internal relay fault output

^CCoE^mC^m0ⁿ7^C0^a-5^o^^CN^on.^^eS^C^A:^ odbus. RTU/ASCII, DNP 3.0, Profibus-DPVI, IEC 61850 (with interface adapter) <

• Connectivity package ;

Width148.8mm(1/3ofa19"rack), i

Height frame 265.9 mm (6U) =

Box 249.8 mm i

Depth 235 mm i

ABBOy

Distribution Automation

P.O. Box 699

FI-65101 VAASA, Finland

Phone: +358 10 22 11

Fax: +358 10 22 41094

www.abb.com/substationautomation