Schweitzer Engineering Laboratories SEL-251C-1 Instruction Manual Download

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Summary of Contents for SEL-251C-1

Page 1: ...UND OVERCURRENT RELAY SELECTABLE SETTING GROUPS CIRCUIT BREAKER MONITOR SELOGIC CONTROL EQUATIONS INSTRUCTION MANUAL SCHWEITZER ENGINEERING LABORATORIES INC 2350 NE HOPKINS COURT PULLMAN WA USA 99163 5603 TEL 509 332 1890 FAX 509 332 7990 Courtesy of NationalSwitchgear com ...

Page 2: ...spective holders Schweitzer Engineering Laboratories SELogic Connectorized Job Done SEL PROFILE SEL 5030 ACSELERATOR and SEL are registered trademarks of Schweitzer Engineering Laboratories Inc The English language manual is the only approved SEL manual Copyright SEL 1993 1994 1995 1996 1997 2000 2002 All rights reserved Printed in USA This product is covered by U S Patent Numbers 5 041 737 5 477 ...

Page 3: ...or any damage resulting from unauthorized access Warning Cet equipement est expedie avec des mots de passe par defaut A Installation les mots de passe par defaut devront etre changes pour des mots de passe confidentiels Dans le cas contraire un acces non autorise a I equipement pourrait etre possible SEL decline toute responsabilite pour tout dommage resultant de cet acces non autorise ATTENTION 2...

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Page 5: ...on section has been created to begin a record of revisions to this manual All changes will be recorded in this Summary of Revisions table This revision includes the following changes Replaced Standard Product Warranty page with warranty statement on cover page Appendix A Updated Firmware Version information 20020212 This revision includes the following changes Reissued entire manual Section 2 Adde...

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Page 7: ...LICATIONS SECTION 6 INSTALLATION MAINTENANCE AND TESTING SECTION 7 APPENDICES SECTION 8 Appendix A Firmware Versions Appendix B Main Board Jumper Connector and Socket Locations Appendix C Onebus Program to Compute Test Set Settings for Testing Distance Relays Table of Contents SEL 251C 1 Instruction Manual Date Code 20020212 Courtesy of NationalSwitchgear com ...

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Page 9: ...INTRODUCTION TABLE OF CONTENTS l l Getting Started Overview General Description 1 1 1 2 Table of Contents SEL 251C 1 Instruction Manual Date Code 20000515 i Courtesy of NationalSwitchgear com ...

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Page 11: ...ements Undervoltage logic detects high side transformer fuse operations Six selectable setting groups cover all bus protection contingencies Circuit breaker monitor sums interrupted current in each pole to aid maintenance Selectively backup distribution feeder relays Eleven cycle event report simplifies fault and system analysis Comprehensive voltage current power unbalance and demand metering Con...

Page 12: ...ge torque control of phase overcurrent elements adds security Choose between three phase and single phase pair phase distance or undervoltage torque control Ground Residual overcurrent elements detect ground faults and external inputs can torque control selected overcurrent elements There are two reset characteristic choices for the time overcurrent elements One choice resets the elements if curre...

Page 13: ...nts information you need to understand relay and circuit breaker perfor mance as well as stress on the protected system for every fault Comprehensive Metering Supports Protection Operation and Demand Analysis The relay measures phase and zero sequence voltage and current as well as MW and MVAR Demand and peak demand values for current MW and MVAR are also available Metering also supports protectio...

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Page 15: ...ort Time Overcurrent Element Curve Timing and Time Delay Reset Equations 2 4 2 8 2 14 2 15 2 16 2 16 2 16 2 17 2 19 2 19 2 20 2 23 2 24 2 25 TABLES 2 8 Trip Circuit Monitor Alarm TCMA Truth Table SEL 251C 1 Relay Word Setting Group Selection Input Truth Table Power Supply Self Test Limits Self Test Summary TCI Settings Table 2 1 Table 2 2 Table 2 3 Table 2 4 Table 2 5 Table 2 6 2 11 2 15 2 17 2 19...

Page 16: ...re 2 11 Inverse Curves Figure 2 12 Very Inverse Curves Figure 2 13 Extremely Inverse Curves Figure 2 14 SEL 251C 1 Phase Overcurrent Logic Diagrams Figure 2 15 SEL 251C 1 Ground Residual Overcurrent Logic Diagrams Figure 2 16 SEL 251C 1 Overcurrent and Undervoltage Elements Figure 2 17 SEL 251C 1 Overcurrent and Distance Elements Figure 2 18 SEL 251C 1 Transformer Fuse Blown Detection Logic Figure...

Page 17: ... nominal control voltage is applied 24 Vdc 15 30 Vdc 48 Vdc 30 60 Vdc 250 Vdc 150 300 Vdc Fixed Level Sensitive inputs are provided on relays with 125 Vdc optoisolated inputs The 125 Vdc optoisolated input each draw 6 mA when nominal voltage is applied The inputs operate as shown below 125 Vdc on for 100 150 Vdc off below 75 Vdc 48 V 125 V 250 V Optoisolated Inputs 24 48 Volt 20 60 Vdc 125 250 Vol...

Page 18: ...simulate keying IEC 68 2 1 Fifth Edition 1990 Environmental testing Part 2 Tests Test Ad Cold Severity Level 16 hours at 40 C IEC 68 2 2 Fourth Edition 1974 Environmental testing Part 2 Tests Test Bd Dry heat Severity Level 16 hours at 85 C IEC 68 2 30 Second Edition 1980 Basic environmental testing procedures Part 2 Tests Test Db and guidance Damp heat cyclic 12 12 hour cycle Severity Level 55 C ...

Page 19: ...mated with 200 frequency steps per octave IEC 801 2 Second Edition 1991 04 Electromagnetic compatibility for industrial process measurement and control equipment Part 2 Electrostatic discharge requirements Severity Level 3 IEC 801 3 Electromagnetic compatibility for industrial process measurement and control equipment Part 3 Radiated electromagnetic field requirements Severity Level lOV m Exceptio...

Page 20: ... LEDs BKR EN ALRM INST A B C G o o o o o o o o TARGET RESET FAULT TYPE STATUS DWG 1026 i02c Figure 2 1 SEL 251C 1 Relay Inputs Outputs and Targets Diagram FUNCTIONAL SPECIFICATIONS Phase Overcurrent Elements for Phase and Three Phase Faults See Figures 2 14 2 16 and 2 17 Phase Time Overcurrent Element 51T Curve families moderately inverse inverse very inverse extremely inverse Time dial 0 5 to 15 ...

Page 21: ... respective currents IBc and ICA Supervises the phase distance element 2IP on a per phase to phase basis 50CAB supervises 21AB 50CBC supervises 21BC 50CCA supervises 21CA Can internally torque control other phase overcurrent elements TCI setting Ground Residual Overeurrent Elements for Ground Faults See Figure 2 15 51NT Ground Residual Time Overcurrent Element Curve families moderately inverse inv...

Page 22: ... three phase or phase to phase distance element Single zone self polarized mho Voltage Element for Healthv Low Voltage Indication or Internal Control 127 See Figure 2 16 27AB 27BC 27CA Phase to Phase Undervoltage Elements Setting Range 0 to 250 V line to line secondary 5 1 V Two setting limits 27H and 27L high and low respectively 27 element asserts only if voltage is between 27H and 27L User sele...

Page 23: ...re 2 21 A close failure timer monitors the length of time the CLOSE output contact remains asserted If CLOSE output contact assertion exceeds the CFT time setting the close attempt is unsuccessful The relay opens the CLOSE output contact and the CF bit in the Relay Word asserts The CF bit asserts for 60 cycles Use the CF bit to alarm for close failures or slow close conditions and to trigger event...

Page 24: ...ited or stuck closed 1 1 0 52ATC short circuited or stuck closed or there is an abnormal open circuit in the 52A input circuit path 1 0 1 0 1 1 60 CYCLES 52A TCMA RELAY WORD BIT TCM INPUT 60 CYCLES DWG A7 0823A Figure 2 4 Trip Circuit Monitor Alarm TCMA Logic Besides alarming for an abnormal open circuit in the trip circuit the TCMA bit provides 52A input verification It effectively compares the c...

Page 25: ... assign to INI only 552 Setting Group Selection Input 2 assign to IN2 only 553 Setting Group Selection Input 3 assign to IN3 only TCP External Torque Control Phase Elements TCP inverted sense of TCP TCG External Torque Control Residual Overcurrent Elements TCG inverted sense of TCG 52A Circuit Breaker Status 52A inverted sense of 52A DC Direct Close Trip Circuit Monitor External Trigger of Event R...

Page 26: ...Y BITS IN R 1 R2 R3 AND R4 TZ Z ANY BITS A THROUGH L ANY BITS A THROUGH L R6 ZT AND AND V LAST PART W X AND Y SIMILAR ANY BITS IN R 1 R2 R3 AND R4 ANY BITS IN R1 R2 R4 AND R6 OR TR RC AND ER SIMILAR A2 SIMILAR ANY BITS IN R1 R3 R4 AND R6 ANY BITS IN R2 R3 R4 AND R6 OR A3 f close TRIP output contacts TR A1 close A1 output contact trigger event report ER close A4 output contact A4 DWG 1013 ZO9 Figur...

Page 27: ...ement Phase instantaneous overcurrent element 51T 50LT 50MT 51NT 50NLT 50H Single zone self polarized mho phase distance element for internal torque control Phase instantaneous overcurrent element operates on phase to phase difference currents Phase undervoltage element for internal torque control and blown fuse detection Time delayed 52A Inverse of 52AT Input IN6 bit asserts for control voltage a...

Page 28: ...ayed Variables ST KT and ZT Relay Word variables ST KT and ZT are outputs from time delay pickup dropout timers TS TK and TZ respectively TS and TK are driven by any OR combination of Relay Word elements inRl R3 and R1 R4 respectively Any AND combination of Relay Word elements A through L may drive timer TZ TS ST RELAY WORD BIT S TK KT RELAY WORD BIT K TZ ZT RELAY WORD BIT Z DWG A7 0824 Figure 2 6...

Page 29: ...perations ALARM The ALARM output closes for the following conditions Three unsuccessful Level 1 access attempts 1 second pulse Any Level 2 attempt 1 second pulse Self test failures permanent contact closure or 1 second pulse depending on which test fails see Table 2 5 The ALARM output closes momentarily when relay settings setting groups or passwords are changed It also closes when a date is enter...

Page 30: ...d the 5IP pickup setting at the time of trip The residual current indicator G similarly shows if residual current exceeds the 51NP pickup setting at time of trip The last three indicators BKR EN ALRM show the state of the breaker illuminated if breaker closed and the relay enabled normal operation or system alarm INST A B C G RS CY LO FAULT TYPE 79 DWG 1076 106 Figure 2 8 SEL 25I 1 Relay Front Pan...

Page 31: ...nly SSI assigned GROUP command selection determines settings to use if the input assigned to SSI is not asserted If the input is asserted setting Group 1 is used For example to switch between Group 1 and Group 5 program input INI to SSI and use the GROUP command to select Group 5 With IN1 asserted the relay uses Group 1 With IN1 deas serted it uses Group 5 When the status of any assigned setting g...

Page 32: ...sum of the interrupted current in each circuit breaker pole for relay and external trips Running sums for relay trips use the current present one cycle after the trip output contacts assert Running sums for external trips use the currents present when the circuit breaker status input 52A or 52A indicates that the circuit breaker has opened You can access the circuit breaker operation data using th...

Page 33: ...he relay disables the breaker control functions and places its output driver port in an input mode No outputs may be asserted when the instrument is in this configuration The relay runs all self tests on power up and before enabling new settings During normal operation it performs self tests at least every few minutes Offset The relay measures the offset voltage of each analog input channel and co...

Page 34: ... by the microcomputer The ADC test verifies converter function by checking conversion time The test fails if conversion time is excessive or a conversion starts and never finishes There is no warning state for this test While an ADC failure disables protective functions control functions remain intact The relay transmits a STATUS message and closes the ALARM relay contacts Master Offset The master...

Page 35: ...100 pulses and divided into fields The relay decodes second minute hour month and day fields and sets the relay clock accordingly When IRIG B data acquisition is activated either manually with the IRIG command or automatically the relay reads two consecutive frames The older frame is updated by one second and the two frames are compared If they do not agree the relay considers the data erroneous a...

Page 36: ...ontrolled Ground residual overcurrent elements can only be externally torque controlled External Torque Control The ETC l setting selects overcurrent elements to be externally torque controlled Only overcurrent elements in Relay Word row R1 can be selected As an example 51P 50NL and consequently 51T and 50NLT are selected for external torque control External Torque Control Phase Overcurrent Elemen...

Page 37: ...controls phase overcurrent elements selected in the ITC l setting 51P and 50M and consequently 51T and 50MT in this example If 27 asserts the selected phase overcurrent elements are enabled with respect to internal torque control If you set TCI equal to 3 the phase overcurrent elements selected in the ITC l setting 51P and 50M and consequently 51T and 50MT in this example are torque controlled by ...

Page 38: ...ase voltages all go to zero If a VT secondary fuse blows while the transformer bank is otherwise operating normally two of the phase to phase voltages presented to the relay drop to 0 58 per unit of nominal If two VT secondary fuses operate one phase to phase voltage measured by the relay goes to zero while the other two drop to 0 58 per unit With these facts in mind the logic described below is e...

Page 39: ...IC Control Equations for tripping or programmable output contact operation DEMAND AMMETERS The SEL 251C 1 Relay provides demand ammeters for phase and zero sequence ground residual currents Peak demands are saved The demand ammeters behave much like low pass filters responding to gradual trends The demand ammeter time constant is used for all three demand ammeters The time constant is settable fro...

Page 40: ...lay element states outputs and inputs using a simple process making the report compact and easy to interpret Use the EVENT command to access the eleven cycle event reports Use the HISTORY command to list summary event reports See Section 3 COMMUNICATIONS for more information on these commands Event Report Triggering Set the variable ER 1246 to any OR combination of elements in Relay Word rows Rl R...

Page 41: ...dial setting the percentage of disc travel and the amount of current between zero and pickup The time delay reset equations tr are given below tM curve operating time in seconds reset time in seconds for time delay reset TD time dial setting M multiples of pickup For curve operating time tM M 1 For reset time tr M 1 Curve 1 Moderately Inverse see Figure 2 10 tr 0 668 TD 0 157 1M TD tr 0 949 0 936M...

Page 42: ...0 40 40 30 30 1500 1260 1500 1250 20 20 8S BOO 500 10 800 500 10 a 8 8 6 300 250 G 300 250 6 S z ss 4 A IT L v V g 3 g A v N 150 126 10 150 126 linAXSI CIS S XV i 2 2 jg s S VS S 15 00 8 8 V s NS N s 02 CQ A 12 00 10 00 N sSs s N s s s 5 S n jp X s 60 60 80 60 s E 5 s 03 r B 00 J A E v 5 s o V 16 00 p 5 s 8 00 5 00 8 8 12 00 10 00 S I rx 30 25 5 I 5 5 30 25 S 6 1 4 00 k v 8 00 5 V v V XN 3 00 3 6 ...

Page 43: ...C S K 1 51T 0 SK 1 f9 51TD TCP ETC 51T TRIP THRESHOLD f2 51TD 2 TCI ITC IMAX 50LT TCP I 50L AND OR 50LT 3 4 ETC 0 TCI ITC SETTABLE TIMER 50H 50LT RELAY WORD BITS SHOWN IN BOLD IMAX TCP AND 50H 4 ETC TCI ITC DWG A7 0845 Figure 2 14 SEL 251C 1 Phase Overcurrent Logic Diagrams Date Code 20000515 Specifications SEL 251C 1 Instruction Manual 2 27 Courtesy of NationalSwitchgear com ...

Page 44: ...NC S t K 1 ETC 51NT f 51NTD 0 SK 1 51NT TRIP THRESHOLD f 2 51NTD 50NL 50NLT 50NL IR AND 50NLT 2 0 TCG ETC 50NH SETTABLE TIMER 50NLT IR AND RELAY WORD BITS SHOWN IN BOLD 50NH 3 TCG OR 4 ETC DWG A7 0844 Figure 2 15 SEL 251C 1 Ground Residual Overcurrent Logic Diagrams Date Code 20000515 Specifications SEL 251C 1 Instruction Manual 2 28 Courtesy of NationalSwitchgear com ...

Page 45: ...7C NOTE 27 IS ALSO AN OPTIONAL INTERNAL TORQUE CONTROL ELEMENT FOR THE PHASE OVERCURRENT ELEMENTS VIA THE TCI SETTING RELAY WORD BITS SHOWN IN BOLD DWG A7 0873 Figure 2 16 SEL 251C 1 Overcurrent and Undervoltage Elements Date Code 20000515 Specifications SEL 251C 1 Instruction Manual 2 29 Courtesy of NationalSwitchgear com ...

Page 46: ... 50C 2 BC AND 21CA AND 4 21 PC 3 4 3 50CCA SETTABLE CONDITION NOTE 50C AND 21PARE ALSO AN OPTIONAL INTERNAL TORQUE CONTROL ELEMENT FOR THE PHASE OVERCURRENT ELEMENTS VIA THE TCI SETTING 21PC RELAY WORD BITS SHOWN IN BOLD DWG A7 0872 Figure 2 17 SEL 251C 1 Overcurrent and Distance Elements Date Code 20000515 Specifications SEL 251C 1 Instruction Manual 2 30 Courtesy of NationalSwitchgear com ...

Page 47: ...27L SETTAB1 F CONDITION 27C RELAY WORD BITS SHOWN IN BOLD DWG A7 0873A Figure 2 18 SEL 251C 1 Transformer Blow Fuse Detection Logic Date Code 20000515 Specifications SEL 251C 1 Instruction Manual 2 31 Courtesy of NationalSwitchgear com ...

Page 48: ...HOWN B PHASE AND C PHASE LOGIC SIMILAR 1 NDEM threshold setting NDEM threshold exceeded GROUND RESIDUAL DEMAND CURRENT METER D ND t IR GROUND RESIDUAL PEAK DEMAND CURRENT METER D PND PEAK DETECTOR RESET PND ND t METER RP RESET ND t 0 METER RD OR setting group change setting DEMR Y AND 3 3 SETTABLE TIME CONSTANT DATC RELAY WORD BITS SHOWN IN BOLD DWG 1076 112 Figure 2 19 SEL 251C 1 Demand Ammeters ...

Page 49: ...SEL 251C 1 Programmable Trip Logic Diagram close CLOSE output contact RECLOSING RELAY OPEN INTERVAL TIME OUT OR close and seal in CLOSE output contact AND 2 OR CLOSE COMMAND DC DIRECT CLOSE INPUT 1 1 open CLOSE output contact close and seol in TRIP output contacts see SEL 251 1 and Programmable Trip Logic Diagram 52A derived from 52A I52A 52AR or I52AR input CLOSE FAILURE TIMER assert when CFT 0 C...

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Page 51: ...escriptions SEL 251C 1 Relay Command Summary 3 1 3 1 3 3 3 5 3 7 3 33 TABLES Table 3 1 Table 3 2 SEL 251C 1 Relay Serial Port Connector Pin Assignments Target LED Assignments 3 3 3 18 FIGURES Figure 3 1 9 Pin Connector Pin Number Convention 3 2 Date Code 20000515 Table of Contents SEL 251C 1 Instruction Manual 1 Courtesy of NationalSwitchgear com ...

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Page 53: ...er case brackets ENTER Note Relay output appears boxed and in the following format Date 12 01 93 Time 01 01 01 Example 21 6 kV distribution bus SERIAL PORT CONNECTIONS AND CONFIGURATIONS Port 1 and Port 2 are EIA 232 serial data interfaces Port 1 is located on the rear panel and is generally used for remote communications via a modem or the SEL PRTU Port 2 has connectors on both the front and rear...

Page 54: ...0 baud and Port 2F 2R set to 2400 baud Caution The serial data format is Eight data bits Two stop bits E2 model or one stop bit E1 model No parity This format may not be changed Figure 3 1 shows the pin number convention for the EIA 232 data ports 5 4 3 2 1 o o o o o o o o o 9 8 7 6 0 female chassis connector as viewed from outside panel Figure 3 1 9 Pin Connector Pin Number Convention Table 3 1 l...

Page 55: ...tors CTS and transmits characters only if CTS is asserted Ground for ground wires and shields 7 RTS RTS 8 CTS CTS 9 GND GND COMMUNICATIONS PROTOCOL Communications protocol consists of hardware and software features Hardware protocol includes the control line functions described above The following software protocol is designed for manual and automatic communications 1 All commands received by the ...

Page 56: ... should terminate at the end of the message in progress when XOFF is received and may resume when the relay sends XON 4 You can use an XON XOFF procedure to control the relay during data transmission When the relay receives XOFF during transmission it pauses until it receives an XON character If there is no message in progress when the relay receives XOFF it blocks transmission of any message pres...

Page 57: ...evel 2 with the 2ACCESS command and second password The Level 2 password is factory set to TAIL and may be changed with the PASSWORD command Startup Immediately after power is applied the relay transmits the following message to the port s designated automatic Date 12 01 93 Time 01 01 01 Example 21 6 kV distribution bus SEL 251C 1 The ALARM relay should pull in The represents the Access Level 0 pr...

Page 58: ... 21 6 kV distribution bus Date 12 01 93 Time 01 03 32 Level 2 You can enter any command at this prompt Command Format Commands consist of three or more characters only the first three characters of any com mand are required You may use upper or lower case characters without distinction except in passwords You must separate arguments from the command by spaces commas semicolons colons or slashes Yo...

Page 59: ...evel 1 If you enter incorrect passwords during three consecutive attempts the relay pulses the ALARM contact closed for one second This feature can alert personnel to an unauthorized access attempt if the ALARM contact is connected to a monitoring system Access Level 1 Commands 2ACCESS 2ACCESS allows you to enter Access Level 2 The password is required unless you install jumper JMP103 The second p...

Page 60: ...coinciding change in circuit breaker auxiliary contact input status 52A drops out or 52B asserts and the absence of relay TRIP output contact assertion For trips the relay measures interrupted current in each pole one cycle after the rising edge of TRIP contact assertion For external trips the relay measures interrupted current in each pole when the status of the circuit breaker auxiliary contact ...

Page 61: ...er trips and interrupted currents cannot be accumulated BREAKERR BREAKER R resets sets to zero the circuit breaker trip counters and interrupted current sums The relay also stores reset date and time l BREAKER R ENTER Reset Trip Counters and Current Sums Are you sure Y N Y ENTER Date 12 01 93 Time 09 10 30 Example 21 6 kV distribution bus Rly Trips 0 IA 0 00 From 4 2 91 IC 0 00 09 10 30 KA IB 0 00...

Page 62: ...1 and the relay displays the newest event report You can control transmissions from the relay with the following keystrokes CTRL S CTRL Q CTRL X Pause transmission Continue transmission Terminate transmission The following incidents clear the event buffers Control power interruption Changing any relay setting via the SET commands Changing any relay setting group via the COPY command Switching sett...

Page 63: ...Simply calculate the time difference between the first report generated at fault inception and the second report generated at the TRIP The EVENT column provides an abbreviated indication of the event type The following incidents trigger an event report TRIP output contact assertion ER Event Report trigger programmable variable assertion Input assigned to ET External Trigger function assertion TRIG...

Page 64: ...internal clock calendar time and date to the time code reading and the relay transmits a message with relay ID string date and time IRIG ENTER Example 21 6 kV distribution bus Date 12 01 93 Time 01 45 40 If no IRIG B signal is present or the code cannot be read successfully the relay sends the error message IRIGB DATA ERROR Normally it is not necessary to synchronize using this command because the...

Page 65: ...ws in the opposite direction Q is positive when three phase reactive power flows from the bus and into the line net load on the line has a lagging power factor If Q is negative three phase reactive power flows in the opposite direction net load on the line has a leading power factor If Q 0 no net reactive power is flowing past the relay net load on the line has a unity power factor The optional pa...

Page 66: ...y is interrupted the demand and peak demand values reset to zero METER RD METER RD resets demand values to zero r n METER RD ENTER Reset Demand Meter Are you sure Y N Y ENTER Example 21 6 kV distribution bus Date 12 01 93 Time 09 14 15 DEM IA 0 B 0 C 0 R 0 P 0 000 Q o ooo PK IA 412 B 410 C 414 R 15 P 14 701 Q 1 280 L J The demand values automatically reset if an active setting group change is made...

Page 67: ...event unauthorized access Control returns to Access Level 0 automatically after a settable interval of no activity see the TIME1 and TIME2 settings of the SET command QUIT ENTER Date 12 01 93 Time 01 45 40 Example 21 6 kV distribution bus _f SHOWSET n SHOWSET n displays the relay and logic settings for setting Group n n 1 2 3 4 5 or 6 You cannot enter or modify settings with this command The SET c...

Page 68: ... 30 50NL 50 00 51NP 0 50 50L 21 99 51P 2 80 27C 2 TCI Z 51NRS N 51RS N 52ADO 0 TKDO 0 TSPU 0 TZPU 0 TSDO 0 TZDO 0 PRESS RETURN ENTER SELogic Equations S 123 A 12 B 12 51NT C 12 D 12 E 34 F 34 IN6 G 34 H 34 J 1234 K 1234 LC1234 A1 1234 TF A2 1234 NDEM PRESS RETURN ENTER V 56 B F W 56 X 56 Y 56 ZC56 A3 1346 A4 2346 TR 1246 51T 50LT V ER 1246 51P 51NP TF ETC 1 ITC 1 51P Global settings DEMR Y ITT 5 I...

Page 69: ...og channels An out of tolerance offset is indicated by a W warning or F failure following the displayed offset value The PS row indicates power supply voltages in volts for the three power supply outputs If a RAM or ROM test fails the IC socket number of the defective part replaces OK The A D self test checks analog to digital conversion time The MOF test checks dc offset in the MUX PGA A D circui...

Page 70: ...Word row R3 TRIP Relay Word row R4 Relay Word row R5 Relay Word row R6 Inputs ALRM Output Contacts 2 21P 50C 27 3 PDEM CLOS NDEM TF 4 B A C D E F G H 5 KT L J V W X Y ZT 6 IN6 IN5 IN4 IN3 IN2 INI 7 TRIP CLOSE A1 A2 A3 A4 8 These selections are useful in testing checking contact states and reading targets remotely 1 indicates an asserted element 0 indicates a deasserted element The optional command...

Page 71: ...ss the front panel TARGET RESET button to clear the TAR 0 data and illuminate all target LEDs for a one second lamp test If you place the relay in service with a target level other than Level 0 it automatically returns to target Level 0 when an automatic message transmits to a timed out port While this feature prevents confusion among station operators and readers it can be inconvenient if the rel...

Page 72: ...ss ENTER Separate the hours minutes and seconds with colons semicolons spaces commas or slashes To set the clock to 23 30 00 enter n r TIME 23 30 00 ENTER 23 30 00 J L A quartz crystal oscillator provides the time base for the internal clock You can set the clock automatically through the relay time code input with a source of demodulated IRIG B time code TRIGGER TRIGGER generates an event record ...

Page 73: ...atus input 52A or 52A indicates an open circuit breaker and the TRIP outputs are not asserted The CLOSE output relay then remains closed until the circuit breaker status input indicates that the circuit breaker has closed or until the close failure timer CFT expires To close the circuit breaker with this command type CLOSE ENTER The relay responds with the message Close BREAKER Y N Y ENTER yields ...

Page 74: ...designates the Group Variable This variable specifies which setting group to use when no Setting Group Selection inputs are assigned or all assigned inputs are deasserted n 1 2 3 4 5 or 6 You can execute this command at any time but the setting group changes only when no Setting Group Selection inputs are assigned or all assigned inputs are deasserted Otherwise the current setting group remains ac...

Page 75: ...mper JMP104 is installed on the main board TRIP output contacts remain closed for at least the duration of TDUR you must enter a TDUR setting starting with the rising edge of the trip output The TRIP outputs drop out only if none of the overcurrent element pickups in Relay Word row R1 are picked up or if you push the TARGET RESET button on the front panel To open the power circuit breaker by comma...

Page 76: ...mple shows T r1 PASSW0RD ENTER 1 OTTER 2 TAIL J L To change the password for Access Level 1 to BIKE enter the following n r PASSW0RD 1 BIKE ENTER Set J L The relay sets the password pulses the ALARM relay closed and transmits the response Set After entering new passwords type PASSWORD ENTER to inspect them Make sure they are what you intended and record the new passwords Passwords can be any lengt...

Page 77: ...t to retain the old setting press ENTER and proceed to the next group setting The logic variable expressions should contain the name of each Relay Word bit e g 51P and the correct delimiter for OR logic ITC l torque control logic variables Enter the logic expression with no spaces between the Relay Word bits and the delimiters Some examples for AND logic and for the ETC l and M I1 OR logic variabl...

Page 78: ...gs the relay enables them and clears the event buffer If the active group is the same as the one you are setting the ALARM output pulses closed A list of relay settings follow Setting ranges and explanations have been added SET 1 ENTER SET clears events CTRL X cancels SEL 251C 1 R400 Group Settings Group 1 Active group 1 Enter data or ENTER for no change Range 39 characters Example 21 6 kV distrib...

Page 79: ...for ground residual definite time overcurrent element 50NLT Setting range dependent on 51NP setting 0 125 100 00 50NL A sec 0 16000 0 Time delay for ground residual definite time overcurrent element 50NLT 9 50NLT Dly eye 50 00 Pickup for ground residual instantaneous overcurrent element 50NH Setting range dependent on 51NP setting 0 125 100 00 50NH A sec 0 25 12 00 0 50 51NP A sec Pickup for groun...

Page 80: ... overcurrent element 51NT If N 51T resets 1 cycle after 51P drops out A sec Pickup for phase definite time overcurrent element 50MT 50M 100 00 0 50 100 00 Dly eye 50MT 0 Time delay for phase definite time overcurrent element 50MT 0 16000 52APU 52A PU eye Time delay pickup for 52AT 0 0 16000 52ADO 52A DO eye Time delay dropout for 52AT 0 0 16000 TSPU Tmr PU eye Timer TS time delay pickup timer TS o...

Page 81: ...r TK TK output is Relay Word bit KT Input into an inverter output is Relay Word bit L A1 output contact setting A2 output contact setting K 1234 L 1234 Al 1234 TF A2 1234 NDEM 9 The following settings V 56 through Z 56 can be set to equal any AND combination of Relay Word bits A through L which are in Relay Word row R5 and the first three bits of row R6 V 56 B F W 56 X 56 Y 56 Z 56 9 9 9 Input int...

Page 82: ...e starts at the first global setting DEMR The relay prompts you for each global setting and checks entries against established limits as it does during group setting entry see SET n p in this section For the programmable contact inputs INI to IN6 if no function is desired type NA ENTER Type END ENTER after the last setting change The relay displays the new global settings and the active group sett...

Page 83: ...RINGS Rings 1 30 Number of rings after which modem on Port 1 answers Inputs INI through IN6 can be assigned to one of the following functions Setting Group Selection Input 1 assign to INI only Setting Group Selection Input 2 assign to IN2 only Setting Group Selection Input 3 assign to IN3 only SSI SS2 SS3 External Torque Control Phase Overcurrent Elements inverted sense of TCP TCP TCP External Tor...

Page 84: ...the AUTO setting must direct automatic messages to that port The following table shows the effect of each possible setting AUTOMATIC MESSAGE DESTINATION PORT AUTO SETTING 1 1 2 2 3 1 and 2 Event summaries and self test warning and failure reports are automatically transmitted from port s designated automatic regardless of access level if the designated port is not timed out Enter zero as the timeo...

Page 85: ...KER R DATE m d y EVENT n Shows DATE TIME EVENT LOCAT location SHOT TARGETS and CURR maximum fault current for the last twelve events HISTORY Forces immediate attempt to synchronize internal relay clock to time code input Displays present phase and residual current values present real and reactive power values and present line to neutral line to line and zero sequence voltage values Optional n disp...

Page 86: ...ts pulse closed after password entry PAS 1 OTTER sets Level 1 password to OTTER PAS 2 TAIL sets Level 2 password to TAIL Initiates setting procedure for setting group n n 1 2 3 4 5 or 6 Option p directs the relay to begin the setting procedure for setting group n at setting p e g if p 5IP the setting procedure starts at setting 5IP bypassing all settings before 5IP If no optional p is entered the ...

Page 87: ...erpreting Voltage and Current Data Relay Element Output Contact and Input Data Example Event Reports Firmware Identification 4 1 4 2 4 2 4 4 4 5 4 10 TABLES Table 4 1 4 1 Event Report Triggering Actions Date Code 20000515 Table of Contents SEL 251C 1 Instruction Manual 1 Courtesy of NationalSwitchgear com ...

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Page 89: ...o eliminate multiple records for boundary faults Triggering is recorded to the nearest quarter cycle and referenced to the 16th row of data in the report All reports trigger at row 16 This system allows you to determine the total duration of a long fault which triggers two event reports Simply calculate the time difference between the report generated at fault inception by ER the programmable even...

Page 90: ...arter cycles of pre fault fault and post fault voltage and current information For each quarter cycle of information the relay also records the states of all fault measuring elements outputs and inputs The report also includes settings active during the event This information is useful in reviewing fault inception and duration relay element response fault evolution and breaker reaction time The la...

Page 91: ...peak amplitude of 1 Now consider two samples one taken at t 0 the other taken 90 later They have values 0 and 1 respectively By the above rules the phasor components are X Y 1 0 Now consider a cosine function Its samples taken at t 0 and t 90 are 1 and 0 its phasor representation is 0 1 The phasor 0 1 leads the phasor 1 0 by 90 This coincides with a 90 lead of the cosine function over the sine fun...

Page 92: ...1 P 1 T 1 50LT 50L 50L 50L 50NL 50NLT 0 0 not possible 0 1 0 0 not possible 0 0 1 1 P T 1 0 1 1 P 1 1 T 50MT 50M 50M 50H 50NH 0 0 not possible 1 0 0 0 1 1 P P T 1 1 Internal torque control I Demand current thresholds TCI 50C 27 21P 0 DEM PDEM QDEM NDEM 0 0 0 1 V 0 0 0 0 0 0 I 1 N 1 0 0 0 1 3 0 0 Q 1 1 0 not possible not possible 0 1 0 0 1 3 1 0 0 1 1 0 P 1 0 6 1 5 1 1 0 1 1 7 0 6 1 1 1 1 1 1 1 7 2...

Page 93: ...easing the relay for service Example Event Report 1 shows the first cycle of an event report triggered under normal oper ating conditions for a 21 6 kV distribution bus The report was generated with the TRIGGER command In this excerpt you can immediately see that load currents are balanced by the lack of significant current in the residual current column IR Also note that the line breaker is close...

Page 94: ... Event Report 2 shows all eleven cycles of a fault triggered event report The first three cycles show pre fault conditions The event report was triggered when the 51P element picked up on a BC fault 51P is set to trigger event reports via the programmable event report trigger variable ER 1246 51P is not set to initiate tripping Tripping is initiated if 51T times out 51T is set to initiate tripping...

Page 95: ...lay STATION __ SWITCH NO INSTALLATION EQUIPMENT ROUTINE X OTHER LOAD CONDITIONS STATION READINGS SEL READINGS MW OUTXIN MW0 J MVAR OUTXIN MVAR VOLTS AMPS 11 401 1 987 AS SEEN ON SCREEN la Vb Ic Va Vc COMPANY NOTATION fe Kb l c V b VfeO V c 1st LINE CHOSEN Y COMPONENT 310 171 141 12377 4872 7505 2nd LINECHOSEN CX COMPONENT 9959 11479 16 262 276 1520 CALCULATED R O MAGNITUDE w 310 310 313 12470 1247...

Page 96: ...1440 i i 2500 1920 4558 11398 10613 6178 p 6 pp P 6 pp p 6 pp p 6 pp p 6 pp p 6 pp p 6 pp P 6 pp 1 5 1 5 1 5 1 5 5 580 1710 230 2700 8690 10 1440 2540 1740 1960 4565 10519 2729 6077 0 580 270 11390 8654 10 1440 2540 1960 4572 11390 10498 6055 0 1 5 1 5 1 5 1 5 580 1740 290 2736 8654 5 1440 2540 1740 1970 4579 10498 2736 6048 5 580 290 11390 8654 Phase time overcurrent element 51T is timing to trip...

Page 97: ...2 TCI Z 51NRS N 51RS N TSPU 0 TZPU 0 TSDO 0 TZDO 0 SELogic Equations S 123 A 12 B 12 51NT C 12 D 12 E 34 F 34 IN6 G 34 H 34 J 1234 K 1234 L 1234 A1 1234 TF A2 1234 NDEM V 56 B F W 56 X 56 Y 56 Z 56 A3 1346 A4 2346 TR 1246 51T 50LT V ER 1246 51P 51NP TF ETC 1 ITC 1 51P Input IN6 functions as a permissive trip input for the 51NT Programmable tripping conditions Programmable event report trigger cond...

Page 98: ...Phase Nominal Volts per Phase Fault Locator type Phase Sequence of Power System Recloser Target LEDs Ground OC Elements Voltage Connection extended w fast operate Fast Meter Command A 1 5 B 6 C D n none positive negative none enable and alarm ground E p n 0 F G e H g I wye y b J EEPROM version specifications are interpreted as follows E ER E Z Specifier Specifier Meaning Option Description Option ...

Page 99: ...d Driven Setting Group Selection 5 3 5 5 5 6 5 7 5 8 5 9 5 10 5 10 5 11 5 12 5 12 FIGURES 5 1 50C Delayed by TSPU Time Effect of 52APU and 52ADO Settings on Relay Word Bits 52AT and 52BT 5 2 Minimum Response Time Using Ground Residual Elements Input IN5 Qualified by Time TKPU Element 27 Qualified by Time TKPU Underfrequency or Undervoltage Trip Condition Time Duration Limit Distribution Feeder Rel...

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Page 101: ...mentations are possible One scheme uses the 50C Relay Word bit the other uses the 52AT Relay Word bit Blocking Scheme for Cold Load Inrush Using the 50C Bit 50C can assert with the presence of load current or deassert in its absence With this setting 50C indicates whether the circuit breaker is closed or open This scheme is not 52A depen dent To block an overcurrent element for cold load inrush fo...

Page 102: ...es If a fault occurred during minimum load times 50L would be delayed from operating for the fault for TSPU time Blocking Scheme for Cold Load Inrush Using the 52AT Bit The 52APU and 52ADO settings affect Relay Word bits 52AT and 52BT as follows 52A 52AD0 52APU Relay Word bits 52AT 52BT Figure 5 2 Effect of 52APU and 52ADO Settings on Relay Word Bits 52AT and 52BT Note that 52BT is the inverse of ...

Page 103: ...p block trip or torque control inputs You can apply the principles in the following examples to other elements Disable Grnnnd Residual Overcurrent Elements with Permissive Trip Input When a permissive trip input is energized selected overcurrent elements are enabled for tripping When a permissive trip input is de energized selected overcurrent elements are disabled for tripping Inputs IN5 and IN6 ...

Page 104: ... Residual Overcurrent Elements with Torque Control Input When a torque control input is energized selected overcurrent elements are enabled for operation When a torque control input is de energized selected overcurrent elements are disabled from operation In such a state selected instantaneous overcurrent elements do not pick up if current exceeds their pickup settings Selected definite time overc...

Page 105: ...bles saved to implement other schemes as needed MINIMUM RESPONSE TIME FOR TIME OVERCURRENT ELEMENTS For time overcurrent element coordination problems at higher fault current levels you can incorporate a minimum response time into the time overcurrent element Such a time overcurrent element cannot operate until a set minimum time passes A ground residual time overcurrent element example appears be...

Page 106: ...DDING INPUT Relay Word inputs IN5 and IN6 can be used as time qualified underfrequency load shedding inputs The output of an underfrequency relay is wired into IN5 or IN6 Using SELOGIC Control Equations TP K 1234 INS TKPU KT RELAY WORD BIT K TKDO Relay Word Bits K 1234 IN5 TKPU TKDO KT Figure 5 4 Input IN5 Qualified by Time TKPU Applications SEL 251C 1 Instruction Manual Date Code 20000515 5 6 Cou...

Page 107: ...lay Word bit Using SELOGIC Control Equations TK K 1234 27 TKPU KT RELAY WORD BIT K TKDO Relay Word Bits K 1234 27 TKDO TKPU KT Figure 5 5 Element 27 Qualified by Time TKPU The TKPU time qualifies the undervoltage condition Continuing with SELOGIC Control Equations TR is the programmable trip condition TR 1246 KT close TRIP output contacts TR A system undervoltage condition is a three phase phenome...

Page 108: ...frequency or undervoltage load shedding applications close TRIP output contacts TR 1246 In this example a false breaker failure operation can occur if KT remains asserted long enough for the trip failure timer to expire This problem can be overcome if trip condition KT is qualified by the presence of load current or limited in duration Qualify Trip Condition with Presence of Load Current Phase ins...

Page 109: ...tage application L limits the duration of KT TR is the programmable trip condition KT L close TRIP output contacts TR S 123 and KCI234 IN5 or 27 TKPU KT TSPU L ST L NOT ST V 56 KT L TFT TFT TSPU TKPU Figure 5 6 Underfrequency or Undervoltage Trip Condition Time Duration Limit RESIDUAL CURRENT UNBALANCE ALARM The NDEM bit asserts when current exceeds ground residual demand threshold setting NDEM Us...

Page 110: ...CKUP FEEDER RELAYS WITH A BUS RELAY Use one SEL 251C 1 Relay to backup the SEL 251 Relays installed on individual feeders The feeder relay ALARM contact can supervise a trip from the bus relay because backup is required only when the feeder relay fails Because of this supervision the bus relay TRIP output contacts can be set to operate simultaneously with feeder relay TRIP output contacts both att...

Page 111: ... REVISION A MAIN BOARDS ONLY Figure 5 7 Distribution Feeder Relay Backup Scheme BUS RELAY SETTING CHANGES Bus relays back up feeder relays If feeder relay protection settings are changed bus relay settings may also need to be changed for coordination purposes Save bus relay setting groups for different feeder relay backup scenarios Bus sections can be paralleled for bus breaker maintenance or othe...

Page 112: ...elect appropriate settings DEMAND DRIVEN SETTING GROUP SELECTION Trigger a change to less sensitive settings when demand phase negative sequence or ground residual encroaches on relay settings thus avoiding nuisance trips Set an alarm so problems can be investigated Applications SEL 251C 1 Instruction Manual 5 12 Date Code 20000515 Courtesy of NationalSwitchgear com ...

Page 113: ... 27 V 1 1 sec 0 250 High Set Limit for Undervoltage Element 27 V 1 1 sec 0 250 Select whether 27 is Phase to Phase 2 Three Phase 3 or Enable High Side Blown Fuse Protection 4 Internal Torque Control Conditions 0 None V 27 I 50C 3 27 50C Z 21P 5 21P 27 6 21P 50C 7 all 50C 27L 27H 27C TCI Residual Ground Definite Time Instantaneous Overcurrent Elements Residual Ground Definite Time Overcurrent Picku...

Page 114: ...4 Extremely Inverse Electromechanical Reset Y N 51P _ 51TD 51C 5IRS Phase Definite Time 50MT Overcurrent Element Phase Definite Time Overcurrent Pickup A sec 0 50 100 00 Phase Definite Time Overcurrent Time Delay cycles 0 16000 50M _ 50MT 52A Time Delay Data Time Delay Pickup for 52AT cycles 0 16000 Time Delay Dropout for 52AT cycles 0 16000 52APU 52ADO General Purpose Timers Timer TS Time Delay P...

Page 115: ...bit B B 12 C 12 Relay Word bit C C 12 D 12 Relay Word bitD D 12 E 34 Relay Word bit E E 34 F 34 Relay Word bit F F 34 G 34 Relay Word bit G G 34 H 34 Relay Word bit H H 34 J 1234 Relay Word bit J J 1234 K 1234 Input into Timer TK Output is Relay Word bit KT K 1234 L 1234 Input into an Inverter Output is Relay Word bit L L 1234 Al 1234 Output Contact A1 Al 1234 A2 1234 Output Contact A2 A2 1234 Dat...

Page 116: ... Z 56 SELOGIC OR Variables OR combination of Relay Word rows in parentheses A3 1346 Output Contact A3 A3 1346 A4 2346 Output Contact A4 A4 2346 TR 1246 Programmable Tripping Conditions TR 1246 ER 1246 Programmable Event Report Trigger Conditions ER 1246 Torque Control Elements ETC l Externally Torque Controlled Elements in Relay Word row R1 e g ETC l 51P 50NL ETC l ITC l Internally Torque Controll...

Page 117: ... TGR __ ITT TIME1 TIME2 AUTO RINGS Assignable Inputs INI IN2 IN3 IN4 IN5 IN6 Input Setting Choices Setting Group Selection Input 1 assign to INI only Setting Group Selection Input 2 assign to IN2 only Setting Group Selection Input 3 assign to IN3 only External Torque Control Phase and Negative Sequence Elements inverted sense of TCP External Torque Control Residual Overcurrent Elements inverted se...

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Page 119: ...munications and Clock Connections One Unit at One Location Remote Communications Local Display and Clock Connections Multiple Relay Units at One Location SEL Relay Communications Diagram for Connection to the SEL DTA SEL 251C 1 Relay Typical AC External Current and Voltage Connections SEL 251C 1 Relay Typical DC External Connections Figure 6 1 Figure 6 2 Figure 6 3 Figure 6 4 Figure 6 5 Figure 6 6...

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Page 121: ...ower system current transformer secondaries The four wire wye potential from potential transformer secondaries is optional It is used for fault locating voltage and MW MVAR metering and undervoltage torque control Control Circuits The control inputs are dry For example to assert the IN5 input you must apply control voltage to the IN5 input terminals Each input is individually isolated and a termin...

Page 122: ...he top cover or front panel Jumpers JMP3 and soldered wire jumpers JMP4 through JMP11 are toward the back of the main board and are accessed by removing the top cover EIA 232 Jumpers J6 provides EIA 232 baud rate selection Available baud rates are 300 600 1200 2400 4800 and 9600 To select a baud rate for a particular port place the jumper so it connects a pin labeled with the desired port to a pin...

Page 123: ...ge devices approved by SEL The power is available on either Port 1 or Port 2R Port 2F located on the front of the relay does NOT have power available To install jumpers for supplying power through the rear EIA 232 ports perform the following steps 1 Remove the relay top cover or withdraw the main circuit board 2 Locate jumpers JMP12 5 Vdc JMP13 12 Vdc and JMP14 12 Vdc near the AUX INPUT connector ...

Page 124: ...or 9 Pin Male D Subconnector 5 GND 2 RXD 3 TXD 7 RTS 8 CTS 1 DCD 4 DTR 6 DSR GND 5 TXD 3 RXD 2 CTS 8 DTE Data Terminal Equipment Computer Terminal Printer etc SEL 251C to Modem Cable C222 DCE Device SEL 251C Relay 25 Pin Male D Subconnector 9 Pin Male D Subconnector 7 GND 2 TXD IN 20 DTR IN 3 RXD OUT 8 CD OUT 1 GND GND 5 TXD 3 RTS 7 RXD 2 CTS 8 GND 9 DCE Data Communications Equipment Modem etc Dat...

Page 125: ...y SEL 2020 9 Pin Male D Subconnector 9 Pin Male D Subconnector 3 TXD 2 RXD 5 GND 8 CTS 7 RTS 2 IRIG 3 IRIG RXD 2 TXD 3 GND 5 RTS 7 CTS 8 IRIG 4 IRIG 6 Port 2R J203 rAUX Input J201 Cable C272A Data Only SEL 251C Relay SEL 2020 9 Pin Male D Subconnector 9 Pin Male D Subconnector 3 TXD 2 RXD 5 GND 8 CTS 7 RTS RXD 2 TXD 3 GND 5 RTS 7 CTS 8 cz 6 5 Installation SEL 251C 1 Instruction Manual Date Code 20...

Page 126: ... is updated by one second and the two frames are compared If they do not agree the relay considers the data erroneous and discards it The relay reads the time code automatically about once every five minutes The relay stops IRIG B data acquisition ten minutes before midnight on New Year s Eve so the relay clock can implement the year change without interference from the IRIG B clock Ten minutes la...

Page 127: ...rol voltage Apply nominal control voltage to each input and make sure the corresponding LED illuminates When the test is complete type TAR R ENTER to reset and clear the front panel target LEDs 5 Proceed to Access Level 2 with the 2ACCESS command and second password Be sure the ALARM relay contacts close and open when the relay executes the 2ACCESS command The ALARM pulse will not be detectable if...

Page 128: ... input IN5 and observe Al A2 A3 and A4 output contact assertion 9 Use the STATUS command to inspect the self test status You may wish to save the reading as part of an as left record When local checkout is complete check communications with the instrument via a remote interface if used Make sure the automatic port is properly assigned and that desired timeout intervals are selected for each port A...

Page 129: ...0 3 J202 J201 IN5 ALARM IN1 IN2 IN3 IN4 IN6 TRIP CLOSE A1 A2 A3 A4 TRIP PORT 1 s 4 3 2 1 PORT 2R 5 4 3 2 1 AUX INPUT 5 4 3 2 1 3 E 9 9 6 7 6 9 8 7 6 9 6 7 6 D A N G E R 1 9 IN 2 0 2 1 IN 2 2 2 3 IN 2 4 2 5 IN 2 6 2 7 I N 2 8 15OUT16 17 IN 1 8 9 our10 11our 12 13our1 4 1 our 2 3 OUT 4 5 OUT 6 7 our 8 CONTACT WITH INSTRUMENT TERMINALS MAY CAUSE ELECTRICAL SHOCK WHICH CAN RESULT IN INJURY OR DEATH 3 ...

Page 130: ...TWO I O BOARD 4U MAIN BOARD ONLY 2U DIMENSION 6 97 1 77 0mm 3 47 88 1mm 5 22 1 32 6mm A 3 00 76 2mm 1 75 44 5mm optional 2 25 57 2mm 4 00 101 6mm B NOTE 1 ALL TOLERANCES ARE 0 020 0 51mm 2 TO DETERMINE THE CUTOUT DIMENSIONS CONSIDER BOTH SEL S SPECIFIED TOLERANCE AND THE CUSTOMER S ALLOWED TOLERANCE 3 DRAWING NOT TO SCALE DWG D367 2K DATE 03 MAR 2000 Figure 6 3 SLP Relay Dimensions and Drill Plan ...

Page 131: ...79 AND SEL 279H b 1 AMP VERSIONS SEL 251 SEL 251C AND SEL 267 4 Dwg 200_panelmount 02 08 00 Figure 6 4 Panel Cutout Diagram for Panel Mount Relays MODEM TO TELEPHONE LINE PORT 1 RELAY PORT 2R OR 2F LOCAL PRINTER TIME CLOCK WITH AUX DEMODULATED IRIG B OUTPUT PORT DWG 1005 101 Figure 6 5 Communications and Clock Connections One Unit at One Location Installation SEL 251C l Instruction Manual 6 11 Dat...

Page 132: ...R 4 5 6 SEL IDM 7 8 9 10 1 1 DWG A7 0852 Figure 6 6 Remote Communications Local Display and Clock Connections Multiple Relay Units at One Location SEL DTA TERMINAL EOR INITIAL SETUP ONLY DATA PORT 1 SEL RELAY NOTE DATA PORT 2 PORT 2 8 VOLTAGE AND 8 CURRENT ANALOG OUTPUTS TO SCADA RTU OR OTHER ANALOG MONITORING EQUIPMENT ANALOG OUTPUTS MODEM PORT 1 Figure 6 7 SEL Relay Communications Diagram for Co...

Page 133: ...ent and Voltage Connections OR 4 4 07 09 Q 11 013 015 03 05 017 019 021 023 025 027 0 44 0 1 _L TRIP _L TRIP __ CLOSE __A1 __ A2 __ A3 A4 PS IN5 IN6 ALARM IN3 IN4 IN1 IN2 2 1 08 010 012 014 016 046 Q 45 06 018 020 022 024 026 028 02 04 OPTIONAL CONNECTIONS OPTIONAL CONNECTIONS 52T1 52T2 52C ANNUNCIATOR OR RTU __ 52a ZZ 52a 52a 52b OR 4 4 4 Note CLOSE output contact operation requires a 52A or 52A ...

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Page 135: ...N la lb Va Ic Vb Vc K i i v v COMPANY NOTATION 1st LINE CHOSEN Y COMPONENT 2nd LINE CHOSEN X COMPONENT CALCULATED R 0 MAGNITUDE w 2 Y 1 ANGLE IN DEGREES ARCTAN Y X VALUE OF Va DEGREES TO SUBTRACT TO OBTAIN Va DEGREES 0 R Va DEGREES 0 ANGLE USED TO DRAW PHASOR DIAGRAM o w 2 USE THE VALUES IN ROWS 1 AND 2 ABOVE TO DRAW PHASOR DIAGRAMS BELOW 120 1 20 0 0 120 120 CURRENTS VOLTAGES Courtesy of National...

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Page 137: ...SCREEN lb Ic Va Vb Vc la V V l V l COMPANY NOTATION 1st LINE CHOSEN Y COMPONENT 2nd LINE CHOSEN X COMPONENT CALCULATED R 0 MAGNITUDE w 1 ANGLE IN DEGREES ARCTAN Y X VALUE OF Va DEGREES TO SUBTRACT TO OBTAIN Va DEGREES 0 R Va DEGREES 0 ANGLE USED TO DRAW PHASOR DIAGRAM o w 2 USE THE VALUES IN ROWS 1 AND 2 ABOVE TO DRAW PHASOR DIAGRAMS BELOW 120 1 20 0 120 VOLTAGES CURRENTS Courtesy of NationalSwitc...

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Page 139: ...able 7 4 Current Quantities for 51NT Timing Test Example Phase Phase Mho Test Voltages and Currents BC Fault Phase Phase Mho Test Quantities at MTA 45 Contact Inputs and Terminal Numbers 7 17 7 23 7 24 7 25 FIGURES Figure 7 1 Low Level Test Interface Figure 7 2 Relay Part Number and Hardware Identification Sticker Figure 7 3 Communications Interface Setup Figure 7 4 Three Phase Voltage and Current...

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Page 141: ...p and dropout condition in much the same manner as an output contact See Section 3 COMMUNICATIONS for more informa tion about the TARGET command TARGET Command By employing the target LEDs for testing you need not change the relay settings for testing purposes The relay generates an eleven cycle event report in response to a trip condition or other user selected conditions Each event report contai...

Page 142: ...t module and the inputs to the processing module relay main board You can test the relay processing module using signals from the SEL RTS Low Level Relay Test System Never apply voltage signals greater than 20 volts peak peak to the low level test interface Figure 7 1 shows the signal scaling factors You can test the input module two different ways Measure the outputs from the input module with an...

Page 143: ...ents confusion among station operators and readers it can be inconvenient if the relay tester does not want targets to revert to level 0 To simplify testing using targets set the relay AUTO setting equal to the port which you intend to use Also set that port TIME setting equal to zero This prevents automatic message transmission to a port which may be timed out Remember to reset these settings and...

Page 144: ...nd Descriptions in Section 3 COMMUNICATIONS and Section 4 EVENT REPORTING for a complete understanding of the relay capabilities Equipment Required The following equipment is necessary for initial checkout 1 Terminal with EIA 232 serial interface 2 Interconnecting cable between terminal and relay 3 Source of control power 4 Source of three phase voltages and currents 5 Ohmmeter or contact opening ...

Page 145: ...od MODEL NUMBER MODEL SCHWEITZER ENGINEERING LABORATORIES PULLMAN WASHINGTON USA SEL 251C 1 fsEQ SERIAL NUMBER S N 93336004 PART NUMBER AND HARDWARE ID 4 125 VAC DC POWER SUPPLY 5 67 120 VAC SECONDARY INPUT VOLTAGE 251C001 4556XHNB PART U 125 VAC DC 14 WATTS POWER SUPPLY 125 VDC LOGIC INPUT 5 5A SECONDARY INPUT CURRENT ROTATION HERTZ V D AMPS SECONDARY INPUT 6 60 HZ SYSTEM FREQUENCY ABC 5 60 0 150...

Page 146: ...Section 6 INSTALLATION for cable pinout listing Communications cable may be connected to PORT 1 or 2 Verify baud rate settings to ensure proper communications and COMPUTER W SERIAL EIA RS 232 C PORT OR PRINTING TERMINAL W SERIAL EIA RS 232 C PORT Figure 7 3 Communications Interface Setup Step 4 Purpose Establish control power connections Method Connect a frame ground to terminal 46 on the rear pan...

Page 147: ...curs turn off the power and refer to Trouble shooting later in this section The prompt indicates that communications with the relay are at Access Level 0 the first of three levels The only command accepted at this level is ACCESS which opens communications on Access Level 1 If you are using a battery simulator be sure the simulator voltage level is stabilized before turning the relay on Note Step ...

Page 148: ...he terminal Method r T Example 21 6 kV distribution bus Date 12 1 93 Time 01 04 56 SELF TESTS W Warn F Fail IR IA IB IC VA VB VC 0 0 0 0 0 0 0 5 08 RAM ROM A D OS 14 92 14 99 MOF SET PS OK OK OK OK OK j Maintenance and Testing SEL 251C 1 Instruction Manual Date Code 20000515 7 8 Courtesy of NationalSwitchgear com ...

Page 149: ... 2 27H 0 00 50NH 50 00 51NC 3 50H 99 99 51C 3 27C 2 TCI Z 51NRS N 51RS N TSDO 0 TZDO 0 TSPU 0 TZPU 0 PRESS RETURN ENTER SELogic Equations S 123 A 12 B 12 51NT C 12 D 12 E 34 F 34 IN6 G 34 H 34 J 1234 K 1234 L 1234 A1 1234 TF A2 1234 NDEM PRESS RETURN ENTER V 56 B F U 56 X 56 Y 56 Z 56 A3 1346 A4 2346 TR 1246 51T 50LT V ER 1246 51P 51NP TF ETC 1 ITC 1 51P s Global settings DEMR Y ITT 5 INI SS1 IN5 ...

Page 150: ... Three Phase Voltage and Current Source Test Connections Step 10 Purpose Verify correct voltage and current connections and levels Method Use the METER command to measure the voltages and currents applied in Step 9 With applied voltages of 69 V per phase and a potential transformer ratio of 180 1 the displayed line to neutral voltages should be 12420 V With applied currents of 2 0 A per phase and ...

Page 151: ...e under standing of relay capabilities study Functional Description in Section 2 SPECIFICATIONS the Command Descriptions in Section 3 COMMUNICATIONS and Section 4 EVENT REPORTING For more test procedures see the Full Functional Test portion of this section FULL FUNCTIONAL TEST This procedure allows you to test the protective and control functions of the relay more fully than the initial checkout p...

Page 152: ...ange the ground residual time overcurrent element pickup from 0 5 A secondary to 0 9 A secondary Type SET 1 51NP and press ENTER Following the 51NP prompt type 0 9 and press ENTER 3 To complete the setting procedure type END and press ENTER Type Y ENTER at the prompt OK Y or N The relay computes internal settings and compares them against fixed limits If all settings are within acceptable ranges t...

Page 153: ...three inputs The phase angle of the voltage and current source should be set to 0 3 Use the METER command to inspect measured voltages currents and power Voltages VA VB and VC should equal the applied voltage times the potential transformer ratio setting With the Example 21 6 kV distribution feeder settings you should obtain 4 50 V 180 9000 V 0 5 vA vB vc Voltages VAB VBC and VCA should read less ...

Page 154: ...rd listed above 2 Disable all external and internal torque control on the overcurrent elements Using the SET command enter NA for the ETC l and ITC l settings These settings specify the overcurrent elements in Relay Word row R1 you want externally and internally torque controlled none in this case 3 Apply current to one phase and observe the pickup and dropout of each element Record the results No...

Page 155: ...ettings These settings specify the overcurrent elements in Relay Word row Rl you want externally and internally torque controlled respectively none in this case 2 Set a programmable output A1 A4 to follow a definite time overcurrent element pickup e g 50NL Use the assertion of this output open to close to start an external timer 3 Set another programmable output to follow definite time overcurrent...

Page 156: ... controlled respectively none in this case 2 Set a programmable output A1 A4 to follow a time overcurrent element pickup e g 51NP Use the assertion of this output open to close to start an external timer 3 Set another programmable output to follow time overcurrent element timeout via the 5INT bit in the Relay Word 51NP drives 51NT Use the assertion of this output to stop the external timer Calcula...

Page 157: ...ements respond to 3x1c current Thus for this test all overcurrent elements see 3 45 A 6 Optional You may want to repeat this test with various multiples of pickup current e g M 3 5 and 7 and various time dial settings e g TD 1 5 and 10 for each of the four curve indexes 7 Repeat these tests for the phase time overcurrent element 51T DEMAND AMMETER TIMING TESTS Purpose Verify the operating time of ...

Page 158: ...lt lo 3 PA IB F Icl 5 5 A Z 0 0 A Z 0 0 A L0 1 67 A Z 0 The residual demand threshold elements respond to 3XIQ current Thus for this test all demand threshold elements see 5 A 4 If the current remains constant at 5 00 A the programmable output contact assigned to the NDEM element asserts 15 minutes after you apply current when DATC 15 5 Repeat these tests for the phase demand threshold alarm PDEM ...

Page 159: ... that the circuit breaker is open Connect the A4 output contact to the same external timer to stop the timer when the A4 output contact asserts A4 contact assertion indicates that the relay failed to close the circuit breaker within the time allotted by the CFT setting CFT 120 cycles A4 CF close failure condition Assert the relay CLOSE output contact using the CLOSE Command or by energizing the IN...

Page 160: ... 1246 50L trip failure condition ETC l NA ITC l NA The setting entry NA not applicable leaves the designated variable blank e g ETC 2 Using the SET G command G signifies the global setting group settings common to all setting groups enter the example settings 5 trip duration time cycles trip failure time cycles TDUR 30 TFT Connect a TRIP output contact to an external timer so that TRIP output cont...

Page 161: ...s after you turn the current off PHASE PHASE MHO ELEMENT TESTS Purpose Determine the pickup of the single zone self polarized mho distance element 21P at three points on the mho characteristic MTA MTA 45 and MTA 45 Method 1 Use the SET command to program a single output relay A1 A4 to follow the distance element 21P Make the following settings CTR CT ratio PT ratio Reach for 21P secondary ohms Max...

Page 162: ...ct dotted relay IC current input to common current source return of current Source B Terminal 33 to source common current return c IA IB IC G VA o G o G o 29 31 33 IA O IB IC IA G VB O G G G 30 32 34 IB G VA VB VC N G VC G G G G G G 40 37 38 39 IC G Figure 7 6a Three Phase Voltage and Two Phase Current Source Test Connections for Phase Phase Mho Test Maintenance and Testing SEL 251C 1 Instruction ...

Page 163: ...tings appear in Table 7 2 Table 7 2 Phase Phase Mho Test Voltages and Currents BC Fault VA VB VC IA IB IC 67 00 57 24 57 24 0 00 1 86 1 86 0 0 125 8 125 8 0 0 163 17 Volts Amps Degrees 4 Adjust the test set voltages and currents to the values in Table 7 2 Do not turn on the currents at this point 5 Turn on the voltage sources VA VB and VC 6 Apply current to the relay and ramp the current source ma...

Page 164: ...TA PTR 25 0Q Z 73 9 00 Z 73 primary CTR Where PTR 180 and CTR 500 Find two other convenient test points Consider a square inscribed in a mho circle with one diagonal being the diameter along the MTA The two corners of that square on the other diagonal are reached by increas ing the current by a factor of 1 414 at angles of 45 from the angle obtained using the ONEBUS program 7 For our phase phase e...

Page 165: ...23 24 25 26 27 28 INI IN2 IN3 IN4 IN5 IN6 SERIAL PORTS TEST Purpose Verify operation of serial Port 1 The initial checkout procedure assumes you connected a terminal to Port 2F on the relay front panel Set the baud rate of Port 1 to match that of Port 2 and switch your terminal from Port 2F to Port 1 Be sure you can communicate through this port Method IRIG B TIME CODE INPUT TEST Purpose Verify op...

Page 166: ...ns are the read points Pin 5 Pin 9 Pin 1 Pin 4 Pin 6 Ground Ground 5 Vdc if JMP12 installed 12 Vdc if JMP13 installed 12 Vdc if JMP14 installed 5 4 3 2 1 0 0 0 0 0 o o o o 9 8 7 6 female chassis connector as viewed from outside panel Figure 7 7 9 Pin Connector Pin Number Convention 3 Compare the 5 volt readings from the status report and voltmeter The voltage difference should be less than 50 mV a...

Page 167: ...nications port Troubleshooting Table All Front Panel LEDs Dark 1 Power is off 2 Blown power supply fuse 3 Input power not present 4 Self test failure 5 Target command improperly set Note For 1 2 3 and 4 the ALARM relay contacts should be closed System Does Not Respond to Commands 1 Communications device not connected to system 2 Relay or communications device at incorrect baud rate or other commun...

Page 168: ...e other than zero 6 Board failure System Does Not Respond to Faults 1 Relay improperly set Review your settings with the SHOWSET command 2 Improper test settings 3 PT or CT input cable wiring error 4 Analog input cable between transformer termination and main board loose or defective 5 Check self test status with STATUS command 6 Check input voltages and currents with METER command and TRIGGER and...

Page 169: ...erance See STATUS command 2 A D converter failure Self Test Failure Offset 1 Offset drift Adjust offsets 2 A D converter drift Self Test Failure ROM Checksum 1 EPROM failure Replace EPROM s Self Test Failure RAM 1 Static RAM IC failure Replace RAM s Self Test Failure A D Converter 1 A D converter failure 2 RAM error not detected by RAM test Alarm Contact Closed 1 Power is off 7 29 Maintenance and ...

Page 170: ...an see the aluminum drawout chassis The main board is attached to the top of the drawout chassis The power supply and transformer assembly are attached to the bottom of the relay chassis 2 Disconnect the power supply and transformer secondary cables from the underside of the drawout assembly 3 Caution This procedure requires that you handle electrostatic discharge sensitive com ponents If your fac...

Page 171: ...h breaker control disabled turn relay power on and enter your settings Execute the STATUS METER and TRIGGER commands to ensure that all functions are opera tional Set and record your Access Level 1 and 2 passwords and the date and time The relay is now ready to resume protective functions 8 FACTORY ASSISTANCE If you have any questions regarding the performance application or repair of this or any ...

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Page 173: ...ons Appendix A l Appendix B Internal Diagram Appendix B l Appendix C One Bus Program to Compute Test Set Settings for Testing Distance Relays Appendix C l Date Code 20020212 Table of Contents SEL 251C 1 Instruction Manual Courtesy of NationalSwitchgear com ...

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Page 175: ...L 251C l R405 This firmware differs from previous versions as follows Added high side blown fuse logic with new 27C setting option Improved operation of Fast Meter and Fast Operate SEL 251C 1 R404 251C 1 60 Hz 5 A base model extended Fast Meter Fast Operate SEL 251C l R403 251C l 60 Hz 5 A base model extended Fast Meter SEL 251C 1 R402 251C l 60 Hz 5 A base model extended Fast Meter SEL 251C 1 R40...

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Page 177: ...a 5 00 n 1 0 0 PO ft O Q 22 ZZZZ n a a a a o 0 cv O cc o cn I OJ gn i OldW Oldnr 009S N 0096 c 2008 N 008 00 Z N 00 Z r OOZi oi 3oozi 009 N 009 r oor H 00C r C a s 1 5 LU in a 2J D S i By LU CD in 2 sEzD EzD 02 o I EID 02 fO O ClP 0 o I c t d w r p 3 ol l i wn i TTT TTT IZldflri oo o o O0 sEl CN sEID ClD LO sen Figure B l SEL 251C 1 Shallow Main Board Troubleshooting Test Points and Jumper Locatio...

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Page 179: ...e ground fault computations Enter source impedance as a per unit value with a base of the previously entered transmission line data For example if the radial system has a source impedance of about ten percent of the entered line impedance enter 0 1 for the per unit distance from the source to the bus Specify the distance from the bus to the fault as a fraction of the total line length To obtain th...

Page 180: ...JA TH VA AR IB AI JB GOSUB 3000 IB RH JB TH VA AR IC AI JC GOSUB 3000 IC RH JC TH VA 80 REM REM ENTER BUS LOC FROM SOURCE INPUT DIST SOURCE TO BUS PU OF LINE M S INPUT DIST BUS TO FAULT PU OF LINE F 1010 90 1020 100 1030 120 1040 130 REM REM PHASE A TO GROUND REM COMPUTE POS SEQ CURRENT 2000 140 2010 150 X R0 2 R1 Y S0 2 S1 R3 Rl RO AR 1 S F 2020 160 S3 Sl SO 2030 170 AI 0 2040 180 BI Y 2050 190 B...

Page 181: ...ER R DATE m d y EVENT n Shows DATE TIME EVENT LOCAT location SHOT TARGETS and CURR maximum fault current for the last twelve events HISTORY Forces immediate attempt to synchronize internal relay clock to time code input Displays present phase and residual current values present real and reactive power values and present line to neutral line to line and zero sequence voltage values Optional n displ...

Page 182: ...cts pulse closed after password entry PAS 1 OTTER sets Level 1 password to OTTER PAS 2 TAIL sets Level 2 password to TAIL Initiates setting procedure for setting group n n 1 2 3 4 5 or 6 Option p directs the relay to begin the setting procedure for setting group n at setting p e g if p 5IP the setting procedure starts at setting 5IP bypassing all settings before 5IP If no optional p is entered the...

Page 183: ...AKER R DATE m d y EVENT n Shows DATE TIME EVENT LOCAT location SHOT TARGETS and CURR maximum fault current for the last twelve events HISTORY Forces immediate attempt to synchronize internal relay clock to time code input Displays present phase and residual current values present real and reactive power values and present line to neutral line to line and zero sequence voltage values Optional n dis...

Page 184: ...ts pulse closed after password entry PAS 1 OTTER sets Level 1 password to OTTER PAS 2 TAIL sets Level 2 password to TAIL Initiates setting procedure for setting group n n 1 2 3 4 5 or 6 Option p directs the relay to begin the setting procedure for setting group n at setting p e g if p 5IP the setting procedure starts at setting 5IP bypassing all settings before 5IP If no optional p is entered the ...

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