1MRS 751802-MUM Protection Relay REX 521 Issued: 27.6.2001 Technical Reference Manual, Standard Configurations Version: C/14.08.2002 Checked: Approved: MK We reserve the right to change data without prior notice. Contents 1. Safety information ..............11 2. Introduction ................12 3. Standard configurations ............17 3.1.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 4.1. Digital inputs ................53 4.1.1. Input selectors ..............54 4.1.2. Input switchgroups (SWGRP) .......... 55 4.1.3. Input signals ..............56 4.2. Function blocks in the overview diagrams of the signal routings 56 4.2.1.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 9.1.5.3. Circuit-breaker failure protection ...... 114 9.1.5.4. Trip-circuit supervision ........115 9.1.5.5. Condition monitoring of the breaker wear ..115 9.1.5.6. Disconnector and earth-switch indication ..115 9.2. Incoming feeder, Basic B01 ............117 9.2.1.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 9.4.6.1. Definite Trip alarm to output relay ....141 9.4.6.2. Digital input to initiate auto-reclosing function ..142 10.Application examples, Medium ...........143 10.1.Outgoing feeder, Medium M01 ..........143 10.1.1.Features .................143 10.1.2.Measurement connections ..........145 10.1.3.Protection ...............145...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 10.3.3.1.Auto-reclosure function ........160 10.3.4.Protection signal routing ..........163 10.3.5.Indication and control connections ........ 163 10.3.6.Implementations ............164 10.3.6.1.Definite trip alarm to output relay ..... 164 10.3.6.2.Digital input to initiate auto-reclosing function . 165 10.3.6.3.Basic angle control by digital input ....
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 11.3.4.1.Protection signal routing ........183 11.3.4.2.Indication and control connections ....183 11.4.Outgoing feeder, High H04 ............184 11.4.1.Features .................184 11.4.2.Measurements ...............186 11.4.3.Measurement connections ..........186 11.4.4.Protection ...............186 11.4.4.1.Non-directional earth-fault protection ....186 11.4.4.2.Auto-reclosure function ........187 11.4.5.Connections ..............187...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 11.6.4.2.Indication and control connections ....198 11.6.5.Implementations ............199 11.6.5.1.Disturbance recorder ........199 11.6.5.2.Power quality ........... 199 12.Symbol notations ..............201 13.References ................203 5HYLVLRQ KLVWRU\ Version C/14.8.2002: - changes in chapters: “Introduction”, “Local/Remote”, “3I2f>”, “Transformer inrush”, “Default set- tings”, “3I>, 3I>>...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Safety information Dangerous voltages can occur on the connectors, even though the auxiliary voltage is disconnected National and local electrical safety regulations must always be followed The device contains components that are sensitive to electrostatic...
Functions (1MRS 750889-MCD) the FB names are used instead of the IEC names. Hardware (HW) versions for the REX 521 are basic, medium, high and sensor. The sensor variant of the standard configuration is indicated as the letter ‘S’ in the “Config.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Table 2.-1 Standard configurations for the REX 521 HW versions Basic Medium High/Sensor Standard configurations B01 B02 M01 M02 H01 H02 H03 H04 H05 H06 IEEE Function FB name...
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PQCU3H PQ 3Unf PQVO3H H01 available only with sensor version of the REX 521 Configured fixedly to the I 0 (1/5 A) channel 3I>-> and 3I>>-> cannot be set to operate as 3I>, 3I>> or 3I>>> 4 Can be used as Io>, Io>> and Io>>> or Uo>, Uo>> and Uo>>> function block with some limitations...
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Table 2.-2 Protection functions available in the different standard configurations of the REX 521 Function Description 3I> Three-phase non-directional overcurrent protection, low-set stage 3I>> Three-phase non-directional overcurrent protection, high-set stage 3I>>>...
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Supervision function of the energizing current input circuit MCS 3U Supervision function of the energizing voltage input circuit Table 2.-6 Power quality monitoring function available in the different standard configurations of the REX 521 Function Description PQ 3Inf Current waveform distortion measurement...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Standard configurations 3.1. HW version: Basic 3.1.1. Standard configuration B01 3.1.1.1. Features • Three-phase non-directional overcurrent protection with three stages • Non-directional earth-fault protection with three stages • Phase discontinuity protection for three phases •...
)LJ %ORFN GLDJUDP RI % 3.1.1.2. Application This standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective short-circuit, time overcurrent and earth-fault protection of radial isolated neutral networks, solidly earthed networks, resistant earthed networks and resonant earthed networks.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations ConfB01 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ % IRU WKH 5(; ...
Technical Reference Manual, Standard Configurations 3.1.2.2. Application The B02 standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective short-circuit protection, time- overcurrent protection, earth-fault protection and automatic reclosing. The...
• Circuit breaker control with indication • Lockout function • Object indication • Logic control position selector • User-configurable I/Os • Interlocking 3I > 50/51 I > CBCM > 3I~harm I > CBFP REX 521 M01 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ 0...
Technical Reference Manual, Standard Configurations 3.2.1.2. Application The M01 standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective short-circuit, time overcurrent and directional earth-fault protection of radial isolated neutral networks, solidly earthed networks, resistant earthed networks and resonant earthed networks.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations ConfM01 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ 0 IRU WKH 5(; ...
• Circuit breaker control with indication • Lockout function • Object indication • Logic control position selector • User-configurable I/Os • Interlocking 3I > 50/51 I > CBCM > 3I~harm I > CBFP REX 521 M02 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ 0...
Technical Reference Manual, Standard Configurations 3.2.2.2. Application The M02 standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective short-circuit protection, time- overcurrent protection, directional earth-fault protection and automatic reclosing.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 3.3. HW version: High/Sensors 3.3.1. Standard configuration H01 (Sensors) 3.3.1.1. Features • Three-phase directional overcurrent protection with three stages • Three-phase transformer inrush and motor start-up current detector • Directional earth-fault protection with three stages •...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 3I> 3I> CBCM I > 3I~harm > I > SYNC CBFP */62 REX 521 H01 )LJ %ORFN GLDJUDP RI VWDQGDUG FRQILJXUDWLRQ +...
Technical Reference Manual, Standard Configurations 3.3.1.2. Application The H01 standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective directional and non- directional short-circuit protection, directional time-overcurrent protection, directional earth-fault protection and automatic reclosing with synchro- and voltage- check functionality.
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Digital Input signals Input SWGRP’s Function blocks Output SWGRP’s Output signals Output relays inputs Ropen SWGRP Open REX 521 Master Trip HSPO1 Io> I<−>Ο CB1 (X4.2.3/4/1/2) Trip 1 ≥1 ≥1 OPEN OOPEN 3I>--> Reset 1 Iub> OPENENA OCLOSE 3I>>--> Lockout 3Ith>...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 3.3.2. Standard configuration H02 3.3.2.1. Features • Three-phase directional overcurrent protection with two stages • Three-phase non-directional overcurrent protection with three stages • Three-phase transformer inrush and motor start-up current detector •...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 3I> 3I> 50/51 CBCM I > 3I~harm > 3U~harm I> CBFP */62 REX 521 H02 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ +...
Technical Reference Manual, Standard Configurations 3.3.2.2. Application The H02 standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective directional and non- directional short-circuit protection, directional and non-directional time-overcurrent protection, directional earth-fault protection and automatic reclosing.
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Digital Input signals Input SWGRP’s Function blocks Output SWGRP’s Output signals Output relays inputs Ropen REX 521 SWGRP Io> I<−>Ο CB1 Open Master Trip HSPO1 OPEN OOPEN (X4.2.3/4/1/2) Trip 1 OPENENA OCLOSE ≥1 ≥1 3I>--> Reset 1 CBFP CLOSE AOPEN Iub>...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 3.3.3. Standard configuration H03 3.3.3.1. Features • Three-phase non-directional overcurrent protection with three stages • Three-phase transformer inrush and motor start-up current detector • Directional earth-fault protection with three stages •...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 3I > 50/51 I > CBCM > 3I~harm I > 3U~harm SYNC */62 CBFP REX 521 H03 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ +...
Technical Reference Manual, Standard Configurations 3.3.3.2. Application The H03 standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective non-directional short-circuit protection, non-directional time-overcurrent protection, directional earth-fault protection and automatic reclosing with synchro- and voltage-check functionality.
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Digital Input signals Input SWGRP’s Function blocks Output SWGRP’s Output signals Output relays inputs Ropen REX 521 SWGRP Open Master Trip HSPO1 3I> I<->O CB1 (X4.2.3/4/1/2) Trip 1 OPEN ≥1 ≥1 3I> Reset 1 OPENENA OOPEN Iub> CBFP 3I>> Lockout...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 3.3.4. Standard configuration H04 3.3.4.1. Features • Three-phase non-directional overcurrent protection with three stages • Three-phase transformer inrush and motor start-up current detector • Directional earth-fault protection with three stages •...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 3I > 50/51 I > CBCM I > 50N/51N 3I~harm > 3U~harm I > CBFP */62 REX 521 H04 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ +...
Technical Reference Manual, Standard Configurations 3.3.4.2. Application The H04 standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective non-directional short-circuit protection, non-directional time-overcurrent protection, directional and non- directional earth-fault protection and automatic reclosing.
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Digital Input signals Input SWGRP’s Function blocks Output SWGRP’s Output signals Output relays inputs Ropen REX 521 SWGRP Open Master Trip HSPO1 3I> I<->O CB1 (X4.2.3/4/1/2) OPEN Trip 1 ≥1 ≥1 3I> OPENENA OOPEN Reset 1 CBFP Iub> 3I>> CLOSE...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 3.3.5. Standard configuration H05 3.3.5.1. Features • Three-phase non-directional overcurrent protection with three stages • Non-directional earth-fault protection with three stages • Three-phase overvoltage protection with two stages • Three-phase undervoltage protection with two stages •...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 3I > 50/51 I > 50N/51N CBCM 3I2f 3I~harm U > 3U~harm 3U> 3U< CBFP */62 REX 521 H05 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ +...
Technical Reference Manual, Standard Configurations 3.3.5.2. Application The H05 standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective non-directional short-circuit protection, non-directional time-overcurrent protection, non-directional earth-fault protection, overvoltage protection, undervoltage protection and residual overvoltage protection.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations ConfH05 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ + IRU WKH 5(; ...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 3.3.6. Standard configuration H06 3.3.6.1. Features • Three-phase non-directional overcurrent protection with two stages • Three-phase overvoltage protection with two stages • Three-phase undervoltage protection with two stages • Residual overvoltage protection with three stages •...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 3I > 50/51 U > CBCM 3U> 3I~harm 3U< 3U~harm f</f> 81U/81O CBFP REX 521 H06 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ +...
Technical Reference Manual, Standard Configurations 3.3.6.2. Application The H06 standard configuration for the REX 521 is designed to be used in single busbar systems using one circuit breaker for selective non-directional short-circuit protection, non-directional time-overcurrent protection, overvoltage protection, undervoltage protection, residual overvoltage protection, underfrequency protection and overfrequency protection.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations ConfH06 )LJ %ORFN GLDJUDP RI WKH VWDQGDUG FRQILJXUDWLRQ + IRU WKH 5(; ...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Reading of the overview diagrams of the signal routings The signals in a standard configuration can be programmed to perform various functions. Digital inputs can be connected to the different input signals (e.g.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Selector Reset 1 Selector Reset 2 Selector Blocking 1 Selector Selector Blocking 2 Selector etc. )LJ 8VH RI LQSXW VHOHFWRUV 4.1.2. Input switchgroups (SWGRP) Switchgroups are used for connecting input signals to the inputs of the function blocks.
CBFP, available in the function. For further information, please refer to the CD- ROM Technical Descriptions of Functions (1MRS 750889-MCD). See also “Introduction” on page 12 for differences between the REX 521 and the RED 500 platform in the function block descriptions of the CD-ROM.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Protection function name Time characteristics 3I>>> CBFP BSOUT Outputs Inputs GROUP START DOUBLE TRIP RESET CBFP CBFP = circuit breaker failure protection )LJ 'HVFULSWLRQ RI IXQFWLRQ EORFN V\PEROV More information concerning function blocks in this manual, refer to section “Function block descriptions”...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 4.4. Other functions described in signal overview diagrams 4.4.1. Lockout function The lockout function is used for increasing the safety when performing control operations. Lockout function can be reset by using the input selector to connect one of the digital inputs (DI1...DI9) to the Lockout reset signal.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Trip signal Lockout Lockout reset Lockout (Normally closed) Close command Lockout2 )LJ 7KH RWKHU RSWLRQ KRZ WR XVH WKH ORFNRXW IXQFWLRQ Note that when the lockout function is in use and an auxiliary power failure occurs, the output relays return to off-state.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations High speed tripping contact 3I> HSPO1 Master trip Open 3I>> (X4.2.3/4/1/2) 3I>>> Io>--> Trip 1 ³1 ³1 Io>>--> Io>>>--> Iub> Lockout 3Ith> HSPO1 Lockout working Lockout reset Lockout 3I>...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Parametrization of the digital inputs Digital inputs can be used for performing different functions like resetting the desired function block by programming the selectors and switchgroups accordingly. Selectors Output...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 5.1.5. Power quality trigger Any of the inputs DI1...DI9 can be used to start the power quality recording measurements. 5.1.6. Master trip An external trip signal can be routed to the heavy duty tripping contact via DI1...DI9.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 5.1.14. AR inhibit, AR on input, start AR Auto-reclosure function O->I can be started, inhibited or turned on via DI1...DI9. 5.1.15. BACTRL (Basic angle control) The basic angle of the directional operation depends on the earthing principle of the network.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Using a digital input directly One of the digital inputs (DI1...DI9) can be selected directly to permit close operations. Use the selector named “Close enable” in the relay menu or the Relay Setting Tool to select the input.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations DC pos. open ≥1 & Interlocking_A DC pos. close ES pos. open & & Interlocking_B ES pos. close )LJ ,QWHUORFNLQJ XVLQJ GLVFRQQHFWRU DQGRU HDUWK VZLWFK VWDWH Using disconnector, earth switch and logical inputs In the cases mentioned above, additional signals, such as SF6 gas low, may be used to block close operations.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Example of customized interlocking DC pos. close = station L/R-switch in remote & ES pos. open = Earth switch open & Interlocking_D = Close enable Logic input 1 = SF6 gas alarm Logic input 2 = Spring not charged &...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Default settings These settings can be found in Main menu\Configuration\. Table 6.-1 Input signals HW versions Basic Medium High/Sensor Standard configuration Input Signals Digital inputs connected Reset 1 Reset 2...
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Table 6.-2 Input SWGRP (Basic and Medium) HW versions Basic Medium Standard configuration Group Iub> Iub> Iub> Iub> 3Ith> 3Ith> 3Ith> 3Ith> Blocking 1 BS1 3I> BS1 3I> BS1 3I>...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Table 6.-3 Input SWGRP (High/Sensor) HW versions High/Sensor Standard configuration BACTRL Table 6.-4 Output SWGRP (Basic and Medium) HW versions Basic Medium Standard configuration Output SWGRP Output Signals Trip 1 3I>...
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Table 6.-4 Output SWGRP (Basic and Medium) HW versions Basic Medium Standard configuration Alarm 1 O<->I CB1 open O<->I CB1 open O<->I CB1 open O<->I CB1 open O<->I CB1 close O<->I CB1 close...
The information in this chapter is adapted from the function block descriptions in the CD-ROM Technical Descriptions of Functions (1MRS 750889-MCD). See also “Introduction” on page 12 for differences between the REX 521 and the RED 500 platform in the function block descriptions of the CD-ROM.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Three-phase non-directional overcurrent protection, low-set stage, 3I> Start current 0.10…5.00 x In Operate time in DT mode 0.05…300.00 s Time multiplier in IDMT mode 0.05…1.00 IEEE time dial in IDMT mode 0.5...15.0...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 7.1.2. Io>, Io>> and Io>>> The non-directional earth-fault protection function blocks are designed for non- directional earth-fault protection whenever the DT characteristic or, as concerns I >, the IDMT (Inverse Definite Minimum Time) characteristic is appropriate.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Non-directional earth-fault protection, low-set stage, Io> Start current 1.0…100.0% of In Operate time in DT mode 0.05…300.00 s Time multiplier in IDMT mode 0.05…1.00 IEEE time dial in IDMT mode 0.5...15.0...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 7.1.3. Io>->, Io>>-> and Io>>>-> The directional earth-fault protection function blocks Io>->, Io>>-> and Io>>>-> are designed to be used for directional or non-directional earth-fault protection whenever the DT characteristic or, as concerns Io>->, the IDMT (Inverse Definite Minimum Time) characteristic is appropriate.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Operation accuracy ±2.5% of set value + 0.0005 x In ±2.5% of set value or + 0.01 x Un Phase angle ±2 ° Start time Injected neutral current > 2.0 x start current and residual voltage >...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 3I> 3I>> CBFP CBFP BACTRL START BACTRL BSOUT TRIP START CBFP TRIP GROUP GROUP CBFP RESET DOUBLE RESET )LJ )XQFWLRQ EORFN V\PEROV RI ,!-> DQG ,!!-> Three-phase directional overcurrent protection, low-set stage, 3I>->...
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Three-phase directional overcurrent protection, high-set stage, 3I>>-> Start current 0.05…40.00 x In Operate time 0.05…300.00 s Operation mode Not in use Definite time Instantaneous Basic angle ϕ 0...90 Oper. Direction...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Three-phase over voltage protection, low-set stage, 3U> Start voltage 0.10...1.60 x Un Operate time 0.05...300.00 s Operation mode Not in use Definite time A curve B curve Time multiplier 0.05...1.00...
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 7.1.6. 3U< and 3U<< Abnormal busbar voltages can be caused by faults in the network or a faulty tap changer or voltage regulator of a power transformer. The function blocks are designed for the single-phase, two-phase and three-phase undervoltage protection whenever the DT characteristic or, as concerns 3U<, the IDMT (Inverse Definite...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 7.1.7. 3I2f> The function block 3I2f> can be used for doubling the set start current of overcurrent protection in a transformer magnetizing inrush situation or at motor start-up. 3I2f>...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Iub> 3∆I> CBFP START TRIP GROUP CBFP RESET )LJ )XQFWLRQ EORFN V\PERO RI ,XE! Phase discontinuity protection, Iub> Start unbalance 10.0…95.0% Operate time 1.0…300.0 s Operation mode Not in use Definite time Note! The values below apply when f/fn = 0.95...1.05...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Three-phase thermal overload protection for cables, 3Ith Time constant for the cable 1…999 min Maximum load current for the cable 1.0…5000.0 A 40.0…150.0 ° C Maximum temperature of conductor -50.0…100.0 °...
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This can be done by selecting O->1 in input SWGRP Reset indications. By default this option is disabled. Note that CB open and CB close have been disabled in the REX 521 via the auto- reclose function. Input SWGRP Output SWGRP O->1 Active...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 7.1.11. Uo>, Uo>> and Uo>>> The residual overvoltage protection function blocks are designed for sensitive earth- fault protection whenever the DT characteristic is appropriate. Suppression of harmonics is possible.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Note: In sensor standard configurations (H01S and H03S) the parameter Control settings\Voltage combine must be enabled and in transformer standard configuration (H03) it must be disabled. The parameter is by default in the correct mode.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 1↔0 CB1 OPEN OOPEN CLOSE OCLOSE CLOSEENA AOPEN BINOPEN ACLOSE BINCLOSE )LJ )XQFWLRQ EORFN V\PERO RI ,!2 &% 7.2.2. I<->O IND1 and I<->O IND2 The object indication function blocks I!O IND1 and I!O IND2 indicate the open, close and undefined states of a disconnector or an earthing switch.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Three-phase current measurement, 3I 0.0…20000.0 A 0.0…20000.0 A 0.0…20000.0 A 0.0…1000.0% In 0.0…1000.0% In 0.0…1000.0% In IL1 demand 0.0…20000.0 A IL2 demand 0.0…20000.0 A IL3 demand 0.0…20000.0 A IL1 demand 0.0…1000.0% In...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Residual voltage measurement, Uo 0…150000 V 0.0…120.0% Un 7.3.4. DREC The transient disturbance recorder DREC is used for recording current waveforms and, when available, voltage waveforms. Furthermore, start and trip signals from the protection functions are recorded.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Transient disturbance recorder, DREC Operation mode Saturation Overwrite Extension Pre-trg time 0…100% Over limit ILx 0.00…40.00 x In Over limit Io 0.00…40.00 x In Over limit Uo 0.00…2.00 x Un AI filter time 0.000…60.000 s...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 7.3.5. The measurement function block 3U measures true RMS phase-to-earth or phase-to- phase voltages. If voltage dividers are used, only phase-to-earth voltages can be measured. If voltage transformers are used, only only phase-to-phase voltages can be measured.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations )LJ )XQFWLRQ EORFN V\PERO RI 34( Three-phase power and energy measurement, PQE P3 (kW) -999999...999999 kW Q3 (kVAr) -999999...999999 kVAr Power factor DPF -1.00...1.00 Power factor PF -1.00...1.00 P3 demand (kW) -999999...999999 kW...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations TCS1 TCSSTATE ALARM )LJ )XQFWLRQ EORFN V\PERO RI 7&6 7.4.3. MCS 3I The supervision function block MCS 3I detects interruptions in energizing circuits. The function block supervises the energizing circuits by comparing the measured phase currents.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 7.5. Power quality 7.5.1. PQ 3Inf The function block PQ 3Inf for current waveform distortion measurement is used for measuring the harmonics and monitoring the power quality in distribution networks.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Current waveform distortion measurement, PQ 3Inf Harmonic limit supervision Limit for THD 0.0... 60.0% Limits for each harmonic 0.0... 40.0% In Recorded data If any limit should be exceeded, the whole harmonic set will be...
Technical Reference Manual, Standard Configurations Example substations All the application examples are designed for typical HV/MV substations like below. 3I > 50/51 > CBCM CBFP 3I~harm REX 521 B01 3I > 50/51 I > 50N/51N CBCM CBFP 3I~harm REX 521 B01 3I >...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 3I > 50/51 U > 59N (67N) CBCM CBFP 3I~harm REX 521 M01 3I > 50/51 3I > 50/51 I > I > CBCM CBCM I > I >...
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Technical Reference Manual, Standard Configurations 3I> 3I> 3I > 50/51 3I > 50/51 CBFP */62 CBFP */62 REX 521 H02 REX 521 H02 Incoming feeder, Incoming feeder, High H02 High H02 3I > 50/51 U > U > 3I >...
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations TRIP circuit breaker CLOSE circuit breaker Blocking signal to the incoming feeder (START 3I>>) Circuit-breaker failure protection Breaker wear alarm Internal relay fault Blocking signal from the residual voltage relay to the Io>...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 9.1.2. Measurement connections The three-phase current transformers are connected to the connector X1.1 on the rear panel. The rated currents of the measuring input are 1 A and 5 A.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations For more information about the phase overcurrent blocking signals between the first and the third application example, please refer to the overview diagram on page 134 (Fig. 9.3.5.-1). The operation of the low-set overcurrent stage 3I> of the relay can be based on a definite- or on an inverse-time characteristic.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations While using the sensitive non-directional earth-fault it is recommended to secure the earth-fault functionality by using the start signal from a residual voltage relay to release blocking of the earth-fault protection. By doing this, unnecessary trips are avoided due to disturbances in the measured earth-fault current.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations highest phase current value. The 3Ith> applies the thermal model of one time- constant for temperature measurement, which means that both the temperature rise and the cooling follow an exponential curve.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations As the HSPO1 is always named as the “Trip 1” output signal, the settings are made directly in Main menu\Configuration\Output SWGRP\Trip 1 where the checksum for the settings is displayed (255 by default).
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 9.1.4.2. Indication and control connections The output signals can be routed to any of the output relays and in this example the circuit breaker close-signal is connected to the power output 3, PO3 (X4.1.17/18).
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations )LJ 6HOHFWLQJ WKH GLJLWDO LQSXW IRU WKH VWDWXV LQGLFDWLRQ RI WKH EUHDNHU LQ WKH 5HOD\ 6HWWLQJ 7RRO In this application example the open and close push buttons are connected to the digital inputs DI7 and DI8.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations selected in the Main menu\Configuration\Output Signals. In this example, the over-current stage 3I>> is routed via Start 1 and then connected to the power output 2, PO2. In this application example, the checksum for the Start 1 is 2.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 9.1.5.4. Trip-circuit supervision The trip-circuit supervision is available for the HSPO1 relay. If the resistance of the trip circuit exceeds a certain limit, for instance due to a bad contact or oxidation, the supervision function will be activated and a trip-circuit supervision alarm signal is provided after an adjustable delay time.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations The status indication signals for the disconnector are named as “DC pos. open” and “DC pos. close” and for the earth-switch as “ES pos. open” and “ES pos. close”. In this example, the disconnector indication signals are connected to the inputs DI3 (open) and DI4 (close).
LV side of the power transformer. 3I > 50/51 I > 50N/51N CBCM CBFP 3I~harm Application Example 2 REX 521 B01 3I > 50/51 I > 50N/51N CBCM I > 3I~harm CBFP Application Example 1...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations TRIP circuit breaker CLOSE circuit breaker Io>>> TRIP to breaker on HV side of transformer Circuit-breaker failure protection OC blocking signal to the HV relay (3I>> START) Internal relay fault...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 9.2.2. Measurement connections The three-phase current transformers are connected to the connector X1.1 on the rear panel. The rated currents of the measuring input are 1 A and 5 A.
A few examples of how the described application can be changed using some of the features of the REX 521 are described below. The back-up protection can be made with the circuit-breaker failure protection function of the protection relay of the outgoing feeder.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations instantaneous trip of the busbar system. On the other hand, it is difficult to find the right setting value since a close-up fault in a feeder can cause the circuit breaker of the in-feeder to trip instead of the feeder protection relay.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations protection function trip signal can be connected or disconnected. When the three- stage overcurrent (3I> 3I>> and 3I>>>), two-stage earth-fault (Io> and Io>>) protection is selected the checksum for Trip 1 is 31.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations overcurrent start signal from the 3I>> stage is routed via Start 1 and then connected to the signal output 2, SO2. The checksum in this application example for Start 1 is 9.2.4.3.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations • periodic triggering Regardless of the triggering type, each recording generates the event E31. The triggering time and reason are included in the recording. Number of recordings can be viewed in Main menu\Measurements\DREC\Control setting\ # records.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations OC-blocking signal to HV-relay (3I>> START) Circuit breaker failure protection OC-blocking signal from outgoing-feeders Io>>> TRIP to breaker on to 3I>>> stage HV side of transformer CLOSE circuit breaker...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 9.3. Transformer feeder, Basic B01 9.3.1. Features This application example describes a transformer feeder including: • overcurrent protection • inrush The application described in this example can serve as a backup protection for a differential protection of the transformer or as main protection for smaller transformers.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 3I > 50/51 > CBCM CBFP 3I~harm Application Example 3 REX 521 B01 3I > 50/51 I > 50N/51N CBCM CBFP 3I~harm Application Example 2 REX 521 B01 3I >...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations TRIP circuit breaker CLOSE circuit breaker Circuit-breaker failure protection Internal relay fault OC blocking signal from the MV relay to the 3I>> stage )LJ &RQQHFWLRQ RYHUYLHZ GLDJUDP RI WKH LQFRPLQJ IHHGHU...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 9.3.2. Measurement connections The three phase current transformers are connected to the connector X1.1 on the rear panel. The rated currents of the measuring input are 1 A and 5 A.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations The high-set overcurrent stage 3I>> is configured to operate in case of a short-circuit in the poles of the LV side. The stage serves also as back-up at short-circuits in the MV busbar system.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations The signal from the inrush function is configured as an input signal to the standard configuration and has to be routed to the overcurrent functions when taken into use.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations timer and the BS2 will block the trip signal. Please refer to the CD-ROM Technical Descriptions of Functions (1MRS 750889-MCD) for more information about the different protection function blocks.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations TRIP circuit breaker CLOSE circuit breaker Blocking signal to incoming feeder (START 3I>>) Circuit-breaker failure protection Definite trip alarm Internal relay fault Blocking signal from the residual voltage relay to the Io>...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 9.4.2. Measurement connections The three-phase current and neutral current transformers are connected to the connector X1.1 on the rear panel. The rated currents of the measuring input are 1 A and 5 A.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations In the following example two auto-reclosures initiated by the start of the protection are carried out. The auto-reclosures are subject to a preset start-delay time initiated from the start signal of the protection.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Instant of fault Start Protection operation time (Trip signal from protection) Circuit breaker Shot 2 Shot 1 Dead time Dead time Close signal Discrimination Time Alarm Definite Trip )LJ $XWRUHFORVH VHTXHQFH ZKHQ $5 LV LQLWLDWHG E\ WKH WULS VLJQDO The reclaim time is always started or restarted at a circuit breaker close operation.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations • go to the Shot 1 setting, select “Initiation mode” as “Trip”, • select “AR1 oper. mode” as “Init Shot” and • set the first “Dead time” as the requirements.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations [↓] push buttons. The checksum for 0->1 Alarm 1 will then be 32. The 0->1 Alarm 1 signal can then be routed to an output contact, in this example SO2, in Main menu\Configuration\Output Signals\.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations TRIP circuit breaker CLOSE circuit breaker Blocking signal to incoming feeder (START 3I>>) Circuit-breaker failure protection Earth-fault TRIP Alarm Overcurrent TRIP Alarm Internal relay fault Control signal for selecting the basic angle of Io>-->...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 10.1.2. Measurement connections The three-phase current, neutral current transformers and residual voltage transformer are connected to the connector X1.1 on the rear panel. The rated currents of the measuring input are 1 A and 5 A and additionally, for earth-fault, 0.2 A. The rated values for voltage are 100 V, 110 V, 115 V and 120 V.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations In this example the digital input DI8 is connected to the input signal BACTRL and then routed to the BACTRL input of the directional earth-fault functions. The BACTRL signal can be found in Main menu\Configuration\Input Signals\BACTRL\ where DI8 is selected.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations The CBFP signal is then connected to any of the output relays via Main menu\Configuration\Output Signals\, and in this example the circuit-breaker failure signal is connected to the power output 1, PO1.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations TRIP circuit breaker CLOSE circuit breaker Uo>> TRIP to the outgoing feeders Circuit-breaker failure protection Uo>> Start to release blocking of outgoing feeders OC blocking signal to the HV relay (3I>> START)
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 10.2.2. Measurement connections The three-phase current transformers and residual voltage transformers are connected to the connector X1.1 on the rear panel. The rated currents of the measuring input are 1 A and 5 A. The rated values for the voltage are 100 V, 110 V, 115 V and 120 V.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 10.2.3.1. Overcurrent protection The overcurrent protection can be implemented as described in the second application example (chapter 9.2.). 10.2.3.2. Residual voltage protection On the busbar, the residual voltage can be measured with a set of voltage transformers in an open-delta connection.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Main menu\Configuration\Input Signals\ Main menu\Configuration\Input SWGRP\ Main menu\Configuration\Output Signals\ Main menu\Configuration\Output SWGRP\. 10.2.5. Implementations In the sections below a few implementation examples for the standard configuration M01 are presented.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations As mentioned above, the start signal from the first high-set overcurrent stage 3I>> can be routed to the first high-set stage 3I>> of the HV relay. To use the start signal from a protection function the signal has to be routed via Main menu\Configuration\Output SWGRP\Start 1 or \Start 2.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations The settings for breaker failure are set separately for each protection function. For example, to set the CBFP time for 3I>> go to Main menu\Protection\3I>>\Control setting where it is possible to set the “CBFP time”...
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Second settings OC-blocking signal to HV-relay (3I>> START) Uo>> Start to release blocking of outgoing feeders Circuit-breaker failure protection OC-blocking signal from outgoing-feeders Uo>> TRIP to outgoing feeders to 3I>>> stage...
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations TRIP circuit breaker CLOSE circuit breaker Blocking signal to incoming feeder (START 3I>>) Circuit-breaker failure protection Definite trip alarm Internal relay fault Control signal for selecting the basic angle of Io>-->...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 10.3.2. Measurement connections The three-phase current, neutral current transformers and residual voltage transformer are connected to the connector X1.1 on the rear panel. The rated currents of the measuring input are 1 A and 5 A and additionally, for earth-fault, 0.2 A. The rated values for voltage are 100 V, 110 V, 115 V and 120 V.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations In the following example two auto-reclosures initiated by the start of the protection are carried out. The auto-reclosures are subject to a preset start-delay time initiated from the start signal of the protection. The first auto-reclosure is delayed only slightly to avoid unwanted auto-reclosures (100 ms).
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations Instant of fault Start Protection operation time (Trip signal from protection) Circuit breaker Shot 2 Shot 1 Dead time Dead time Close signal Discrimination Time Alarm Definite Trip )LJ $Q DXWRUHFORVH VHTXHQFH ZKHQ $5 LV LQLWLDWHG E\ WKH WULS VLJQDO The reclaim time is always started or restarted at a circuit breaker close operation.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations pulse period, the close signal is deactivated. Alarms and action signals are available as three different signals from the auto-recloser. The signals can be found in Main menu\Configuration\Output SWGRP\ and they are named as 0->1 ACTIVE, 0->1 Alarm1 and 0->1 Alarm2.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 10.3.6.2. Digital input to initiate auto-reclosing function If an external start or trip signal is available for initializing the auto-recloser, the signal can be connected to a digital input of the relay. Set the digital input, in this example DI7, for the “0->1 Ext.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations External reclosure initialization signal Definite trip alarm Control signal for selecting the basic angle of Io>--> (BACTRL) Circuit-breaker failure protection Blocking signal to the incoming feeder (START 3I>>) CLOSE circuit breaker...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations TCS1 TRIP1 circuit breaker CLOSE circuit breaker 3I> -> TRIP2 to the HV side circuit breaker Circuit-breaker failure protection OC blocking signal to the HV-side 3I>> stage (3I>>-> START) OC blocking signal to the 3I>>>...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 11.1.2. Measurements Following measurements are supported in this application example: • True RMS measurement of phase currents • True RMS measurement of phase-to-earth voltages • True RMS measurement of residual voltage (calculated value from phase-to-earth voltages) •...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations ∆ • U< dU setting ∆ • f< df setting ∆ ϕ< dphi setting • Before the function block allows the CB closing, it ensures that the phase difference will remain within the setting range until the CB closes.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 11.1.5.2. Circuit-breaker failure protection All of the current-based protection functions in the standard configuration H01 provide a delayed trip signal CBFP after the trip signal unless the fault has not disappeared during the set CBFP time delay.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations TCS1 TRIP1 circuit breaker CLOSE circuit breaker 3I> -> TRIP2 to the HV side circuit breaker Circuit-breaker failure protection OC blocking signal to the HV-side 3I>> stage (3I> START) OC blocking signal to the 3I>>...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 11.2.2. Measurement connections Following measurements are supported in this application example: • True RMS measurement of phase currents • True RMS measurement of phase-to-phase voltages • True RMS measurement of residual voltage •...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations The needed time for blocking includes: Start time of the relay Input delay on the relay + Retardation time Margin (40 ms) to be blocked (30 ms) (20 ms) (10 ms) The set operate time of a back-up protection stage 3I>...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 11.2.4.2. Indication and control connections The connections for indication and control can be implemented as described in the first application example (chapter 9.1.), except the signals for the open and close buttons that in this example are disconnected.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations then connected to any of the output relays via Main menu\Configuration\Output Signals\, and in this example the circuit-breaker failure signal is connected to the power output 1, PO1. 11.2.5.4.
The High H03 variant of the REX 521 is selected to be used in this application because of the synchro-check and voltage-check functionality. This selection makes it possible to extend the automatic supervision functionality in the substation.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations TCS1 TRIP circuit breaker CLOSE circuit breaker Blocking signal to incoming feeder (START 3I>>) Circuit-breaker failure protection Definite trip alarm Internal relay fault TempAlarm Mains ACFail Blocking signal from outgoing...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations 11.3.2. Measurements Following measurements are supported in this application example: • True RMS measurement of phase currents • True RMS measurement of phase-to-phase voltages • System frequency measurement 11.3.3.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations The time grading includes (definite time): 2 X Tolerance of the + Operation time + Retardation time Saturation and delay relays’ operate times of the CB of the relay...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations The command mode is used as a basic control principle of the synchro-check function. In command mode, the synchro-check function directly uses the output signal to close the circuit breaker. The close command e.g. from the HMI is connected to the synchro-check function.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations TCS1 TRIP circuit breaker CLOSE circuit breaker Blocking signal to incoming feeder (START 3I>>) Circuit-breaker failure protection Definite trip alarm Internal relay fault TempAlarm Mains ACFail Control signal for selecting the basic angle of Io>-->...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 11.4.2. Measurements Following measurements are supported in this application example: • True RMS measurement of phase currents • True RMS measurement of neutral current • True RMS measurement of phase-to-phase voltages •...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations EF in phase L2 EF in phase L3 )LJ FURVVFRXQWU\ IDXOW Detection of a cross-country fault can be implemented by non-directional earth-fault protection. In a case where the fault current is lower than the start current level of...
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations TCS1 TRIP circuit breaker CLOSE circuit breaker Io>>> TRIP to breaker on HV side of transformer Circuit-breaker failure protection OC blocking signal to the HV relay (3I>> START) Internal relay fault...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 11.5.2. Measurements Following measurements are supported in this application example. • True RMS measurement of phase currents • True RMS measurement of neutral current • True RMS measurement of phase-to-phase voltages •...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 11.5.4.2. Indication and control connections All the necessary settings for the indication and control signals of the circuit breaker and the disconnector for the incoming feeder can be set as described in the first application example on page 104 onwards for the outgoing feeder (except for the earth-switch).
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations • periodic triggering Regardless of the triggering type, each recording generates the event E31. The triggering time and reason are included in the recording. Number of recordings can be viewed in Main menu\Measurements\DREC\Control setting\ # records.
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1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations TCS1 TRIP1 to the incoming feeder Uo>>>,Uo>> TRIP3 to all outgoing feeders Uo>>>,Uo>>, U<, U<<, U>, U>> and f<< TRIP2 to the load shedding group 1 f< Earth-fault alarm Uo>...
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations 11.6.2. Measurements Following measurements are supported in this application example: • True RMS measurement of phase-to-phase voltages • True RMS measurement of residual voltage • System frequency measurement 11.6.3.
REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations The trip signal (Trip 2) of the underfrequency stage f< protection function is routed to the power output PO2 (x4.2.14/15). The trip signals (Trip 3) of the residual voltage stages Uo>>> and Uo>>, undervoltage, overvoltage and underfrequency stage f<<...
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Main menu\Configuration\Input SWGRP\ Main menu\Configuration\Output Signals\ Main menu\Configuration\Output SWGRP\. 11.6.5. Implementations In the sections below a few implementation examples for the standard configuration H06 are presented. 11.6.5.1. Disturbance recorder The disturbance recorder (DREC) can be found in Main menu\Measurement\DREC\.
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations The function can deliver the alarm signal "PQ 3Unf cum", an output signal for exceeding a setting limit for cumulative probability of a harmonic and the "PQ 3Unf har", an output signals for exceeding a setting limit for a harmonic. The alarm signals can be routed to the output contacts via the switchgroups.
1MRS 751802-MUM Protection Relay REX 521 Technical Reference Manual, Standard Configurations Symbol notations = multiple-stage three-phase overcurrent protection, low-set, high-set and instantaneous 3I > 50/51 stage available = multiple-stage three-phase directional overcurrent protection, low-set, high-set and 3I> instantaneous stage available = multiple-stage earth-fault protection, low-set, high-set and instantaneous stage >...
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REX 521 Protection Relay 1MRS 751802-MUM Technical Reference Manual, Standard Configurations = energy counter, forward or reverse active / reactive energy = measuring circuit supervision = trip circuit supervision = circuit-breaker condition monitoring CBCM = active power measurement, indication and supervision...
• Installation Manual 1MRS 750526-MUM • Technical Descriptions of Functions (CD-ROM) 1MRS750889-MCD 3DUDPHWHU DQG HYHQW OLVWV IRU WKH 5(; • Parameter List for REX 521 1MRS751999-RTI • Event List for REX 521 1MRS752000-RTI • General Parameters for REX 521 1MRS752156-RTI •...