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Sel 551 Instruction Manual

Sel 551 Instruction Manual

Overcurrent relay reclosing relay
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SEL-551 Relay
Overcurrent Relay
Reclosing Relay
Instruction Manual
20110408
*PM551-01-NB*

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  • Page 1 SEL-551 Relay Overcurrent Relay Reclosing Relay Instruction Manual 20110408 *PM551-01-NB*...
  • Page 2 © 1998–2011 by Schweitzer Engineering Laboratories, Inc. All rights reserved. All brand or product names appearing in this document are the trademark or registered trademark of their respective holders. No SEL trademarks may be used without written permission. SEL products appearing in this document may be covered by US and Foreign patents.

  • Page 3: Table Of Contents

    Section 2: Installation Overview ................................. 2.1 Relay Mounting ............................... 2.1 Rear-Panel Connections ..........................2.5 SEL-551 AC/DC Connection Diagrams for Example Applications ............... 2.9 EIA-485 Rear-Panel Adapter......................... 2.14 Circuit Board Jumpers and Battery ....................... 2.15 Section 3: Relay Elements and Logic Relay Word Bits and SEL Control Equations..................
  • Page 4 Instruction Manual ............................A.3 Appendix B: Firmware Upgrade Instructions EPROM Firmware Upgrades .......................... B.1 Flash Firmware Upgrades ..........................B.5 Appendix C: SEL Distributed Port Switch Protocol Overview................................. C.1 Settings................................C.1 Operation ................................ C.1 Appendix D: Configuration, Fast Meter, and Fast Operate Commands Overview.................................D.1...
  • Page 5 Table of Contents Appendix E: Compressed ASCII Commands Overview .................................E.1 CASCII Command—General Format ......................E.1 CASCII Command—SEL-551........................E.3 CSTATUS Command—SEL-551 ........................E.3 CHISTORY Command—SEL-551 .........................E.4 CEVENT Command—SEL-551 ........................E.4 Appendix F: Setting Negative-Sequence Overcurrent Elements Setting Negative-Sequence Definite-Time Overcurrent Elements ..............F.1 Setting Negative-Sequence Time-Overcurrent Elements ................F.1 Coordinating Negative-Sequence Overcurrent Elements ................
  • Page 6 This page intentionally left blank...

  • Page 7: List Of Tables

    Overcurrent Elements......................1.6 Table 2.1 Required Control Voltage Jumper Positions for Applied Nominal Control Voltage (SEL-551 With the Conventional Terminal Blocks Option) ..........2.15 Table 2.2 Required Position of Jumper JMP13 for Desired Output Contact OUT4 Operation... 2.17 Table 3.1 Processing Order of SEL Control Equation Operators...........
  • Page 8 Table G.13 10h Preset Multiple Registers Command ................G.9 Table G.14 64h Scattered Register Read Command ................G.10 Table G.15 SEL-551 Modbus Command Region...................G.11 Table G.16 Modbus Command Codes....................G.11 Table G.17 Assign Event Report Channel Using Address 00B2 ............G.13 Table G.18 Modbus Map ........................
  • Page 9 Relay Dimensions and Drill Plan for Mounting Two SEL-500 Series Relays Together Using Mounting Block (SEL P/N 9101) ................2.3 Figure 2.3 Relay Dimensions and Drill Plan for Mounting an SEL-551 With Rack Mount Bracket 9100 (Bracket on Right Side in Front View)..............2.4 Figure 2.4 SEL-551 Fitted with Mounting Bracket (SEL P/N 9100) for Mounting in 19-Inch Rack ........................
  • Page 10 Local Control Switch Configured as an ON/OFF/MOMENTARY Switch......6.7 Figure 7.1 Example Event Summary .......................7.3 Figure 7.2 Example SEL-551 Standard 15-Cycle Event Report (1/8-Cycle Resolution)......7.14 Figure 7.3 Derivation of Event Report Current Values and RMS Current Values From Sampled Current Waveform ......................7.15 Figure 7.4...

  • Page 11: Preface

    Describes how to enter and record settings. Section 5: Serial Port Communications and Commands. Describes how to connect the SEL-551 to a PC for communication; shows serial port pinouts; lists and defines serial port commands. Section 6: Front-Panel Interface. Explains the features and use of the front panel, including front-panel command menu, default displays, and automatic messages.

  • Page 12: Conventions

    Examples This instruction manual uses several example illustrations and instructions to explain how to effectively operate the SEL-551. These examples are for demonstration purposes only; the firmware identification information or settings values included in these examples may not necessarily match those in the current version of your SEL-551.

  • Page 13: Section 1: Introduction And Specifications

    Transformer Banks—includes connections for a separate Retrofits neutral current transformer ➤ Other Power System Apparatus—capacitors, reactors, circuit breakers, etc. Differences Between The SEL-551C Relay differs from the SEL-551 Relay in the following major areas: the SEL-551/SEL-551C ➤ Different I/O mix. Relays SEL-551...

  • Page 14: Sel-551 Model Changes

    Trip Industrial Distribution Feeder Protection t Figure 2.14; w see Figure 2.11; e see Figure 2.13; r see Figure 2.9; t see Figure 2.10. Figure 1.1 SEL-551 Relays Applied Throughout the Power System SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 15: Hardware Overview

    See Figure 2.8; w see Figure 2.10; e see Figure 2.11; r see Figure 2.12; t see Figure 2.9, Figure 2.13, and Figure 2.14. Figure 1.2 SEL-551 Inputs, Outputs, and Communications Port Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 16: Specifications

    4 mA of current. Ripple: 100% Conventional Terminal Blocks Option 48/125 Vdc or 125 Vac Note: The conventional terminal blocks model of the SEL-551 can be ordered with either jumper-selectable voltage optoisolated Range: 36–200 Vdc or 85–140 Vac inputs or level-sensitive optoisolated inputs.
  • Page 17 Object Penetration Routine Dielectric Strength Object Penetration: IEC 60529:1989 IP 30, IP 54 from the AC current inputs: 2500 Vac for 10 s front panel using the SEL-9103 Power supply, front- cover dust and splash optoisolated inputs, protection and output contacts:...

  • Page 18: Overcurrent Elements

    Figure 1.4 Figure 1.5 show pickup and reset time curves applicable to all the instantaneous overcurrent elements in the SEL-551 (60 Hz or 50 Hz Overcurrent Element relays). These times do not include output contact operating time and, thus, Pickup and Reset are accurate for determining element operating time for use in internal control equations.

  • Page 19: Ct Saturation Protection

    Introduction and Specifications CT Saturation Protection Minimum Maximum Applied Current (Multiples of Pickup Setting) Figure 1.4 SEL-551 Instantaneous Overcurrent Element Pickup Time Curve Minimum Maximum Applied Current (Multiples of Pickup Setting) Figure 1.5 SEL-551 Relay Instantaneous Overcurrent Element Reset Time...

  • Page 20: Timer Specifications

    Combining the two filters provides an elegant solution for ensuring dependable phase instantaneous overcurrent element operation. Timer Specifications The SEL-551 has reclosing relay timers, programmable timers, and other timers (see Section 4: Setting the Relay). All timers are set in cycles, in 1/8 cycle (0.125 cycle) increments.

  • Page 21: Section 2: Installation

    ) wiring. This section also includes information on configuring the relay for your application. Relay Mounting Rack Mount A single SEL-551 Relay is roughly half the size of a standard 19-inch rack (see Figure 2.1 Figure 2.5). To mount the relay in a standard 19-inch rack follow these steps: Step 1.

  • Page 22: Figure 2.1 Sel-551 Dimensions, Panel Cutout, And Drill Plan

    Installation Relay Mounting Figure 2.1 SEL-551 Dimensions, Panel Cutout, and Drill Plan SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 23: Figure 2.2 Relay Dimensions And Drill Plan For Mounting Two Sel-500 Series Relays Together Using Mounting Block (Sel P/N 9101)

    Installation Relay Mounting Figure 2.2 Relay Dimensions and Drill Plan for Mounting Two SEL-500 Series Relays Together Using Mounting Block (SEL P/N 9101) Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 24: Figure 2.3 Relay Dimensions And Drill Plan For Mounting An Sel-551 With Rack Mount Bracket 9100 (Bracket On Right Side In Front View)

    Installation Relay Mounting Figure 2.3 Relay Dimensions and Drill Plan for Mounting an SEL-551 With Rack Mount Bracket 9100 (Bracket on Right Side in Front View) Figure 2.4 SEL-551 Fitted with Mounting Bracket (SEL P/N 9100) for Mounting in 19-Inch Rack...

  • Page 25: Rear-Panel Connections

    Installation Rear-Panel Connections Figure 2.5 SEL-551 Front Panel, Rack-Mount Version (Half-Rack Width) Figure 2.6 SEL-551 Front Panel, Panel-Mount Version Rear-Panel Connections We provide two options for secure connection of wiring to the relay rear panel. One of these is the conventional terminal block, in which you use size #6-32 screws to secure rear-panel wiring.

  • Page 26: Figure 2.7 Sel-551 Rear Panel (Conventional Terminal Blocks Option)

    However, as stated below, SEL strongly recommends the use of ring or fork terminals. Two types of screw terminal are provided on the SEL relays, one with a washer (Phillips screw head - standard) and one without (slotted screw head, optional).

  • Page 27: Figure 2.8 Sel-551 Rear Panel (Plug-In Connectors Option)

    Installation Rear-Panel Connections Connectorized To use the Connectorized version of the SEL-551, ask your SEL sales or customer service representative for the appropriate Model Option Table and order wiring harness kit WA05510WxXyA, where x designates wire size and y designates wire length. You can find the Model Option Table on the SEL website at http://www.selinc.com.
  • Page 28 The arc suppressors in the SEL-551 are different from the SEL-9501 Contact Arc Suppressor. The high-current interrupting output contacts in the SEL-551 have the same interrupt rating as the SEL-9501, but typically have less than 1 µA of leakage current, and exhibit virtually none of the let-through exhibited...

  • Page 29: Ac/Dc Connection Diagrams For Example Applications

    Installation SEL-551 AC/DC Connection Diagrams for Example Applications SEL-551 AC/DC Connection Diagrams for Example Applications SEL-551 Relay (-) Trip Circuit OUT1 Trip Coil Close Circuit OUT2 Close Coil Breaker Failure OUT3 Lock Trip Circuit to Bus Relay (Fast Bus Trip Scheme)

  • Page 30: Figure 2.10 Sel-551 Provides Overcurrent Protection For An Industrial Distribution Feeder (Core-Balance Current Transformer Connected To Current Input Channel In)

    OUT4 to Annunciator or RTU ALARM Figure 2.10 SEL-551 Provides Overcurrent Protection for an Industrial Distribution Feeder (Core-Balance Current Transformer Connected to Current Input Channel IN) A core-balance current transformer is often referred to as a zero-sequence, ground fault, or window current transformer.

  • Page 31: Figure 2.11 Sel-551 Provides Overcurrent Protection For A Delta-Wye Transformer Bank

    SEL-551 Relay (-) Trip Circuit OUT1 Trip Coil Breaker Failure OUT2 Lock Trip Circuit OUT3 OUT4 to Annunciator or RTU ALARM (low-side) Figure 2.11 SEL-551 Provides Overcurrent Protection for a Delta-Wye Transformer Bank Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 32: Figure 2.12 Sel-551 Provides Overcurrent Protection For A Transformer Bank With A Tertiary Winding

    Circuit OUT1 Trip Coil Breaker Failure OUT2 Lock Trip Circuit OUT3 OUT4 to Annunciator or RTU ALARM (tertiary) (low-side) Figure 2.12 SEL-551 Provides Overcurrent Protection for a Transformer Bank with a Tertiary Winding SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 33: Figure 2.13 Sel-551 Provides Overcurrent Protection For A Distribution Bus (Includes Fast Bus Trip Scheme)

    ALARM from Feeder Relays (Fast Bus Trip Scheme) Figure 2.13 SEL-551 Provides Overcurrent Protection for a Distribution Bus (Includes Fast Bus Trip Scheme) The fast bus trip scheme is often referred to as a reverse interlocking or zone interlocking scheme.

  • Page 34: Eia-485 Rear-Panel Adapter

    Annunciator or RTU ALARM Breaker Failure Initiate Figure 2.14 SEL-551 Provides Dedicated Breaker Failure Protection EIA-485 Rear-Panel Adapter Cable C675 is used with the EIA-485 rear-panel serial communications port option to bring the pins from the 9-pin serial communications connector (see Figure 5.1) out to a terminal block for ease of wiring.

  • Page 35: Circuit Board Jumpers And Battery

    Step 9. Replace the relay front panel. Step 10. Reenergize the relay. Table 2.1 Required Control Voltage Jumper Positions for Applied Nominal Control Voltage (SEL-551 With the Conventional Terminal Blocks Option) For use with relays equipped with the jumper-selectable control input voltage option only. Not supported in the level-sensitive control input option.

  • Page 36: Figure 2.15 Input And Output Jumper Locations (Sel-551 Relay With The Conventional Terminal Blocks With Jumper-Selectable Control Input Voltage Option)

    JMP10 JMP11 JMP7 JMP8 Figure 2.15 Input and Output Jumper Locations (SEL-551 Relay With the Conventional Terminal Blocks With Jumper-Selectable Control Input Voltage Option) Password and Password and Breaker jumpers are on the front edge of the relay main board between the front-panel LEDs and the control pushbuttons.

  • Page 37: Table 2.2 Required Position Of Jumper Jmp13 For Desired Output Contact Out4 Operation

    Some initial shipments of Figure 3.23. If jumper JMP13 is in position ALARM and both output contacts SEL-551 relays did not have this OUT4 and ALARM are the same output contact type (a or b), they will be in the jumper JMP13 feature.
  • Page 38 Step 9. Replace the relay front panel and reenergize the relay. Step 10. Set the relay date and time via serial communications port or front panel (see Section 5: Serial Port Communications and Commands Section 6: Front-Panel Interface, respectively). SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 39 SHO Command (Showset) for a OGIC listing of the factory SEL control equation settings shipped with the relay. OGIC Create traditional or advanced custom schemes with SEL control OGIC equations. control equation settings are written in Boolean algebra logic, OGIC combining Relay Word bits together with different operators.

  • Page 40: Section 3: Relay Elements And Logic Relay Word Bits And Sel Ogic Control Equations

    Table 3.1. OGIC Up to 16 total rising-edge and falling-edge detects can be used in SEL OGIC control equations settings for the SEL-551 relay. Processing Order and The relay elements and logic (and corresponding SEL...

  • Page 41: Optoisolated Inputs

    Figure 3.1 for the optoisolated inputs available with the SEL- 551 relay. This figure gives an example of an energized and de-energized optoisolated input and corresponding Relay Word bit states. Note the built-in pickup and dropout times of 0.25 cycles for energization or de-energization debounce.
  • Page 42 Optoisolated inputs IN1–IN2 receive their function by how their corresponding Relay Word bits IN1–IN2 are used in SEL control equations. OGIC Factory Settings Relay Word bit IN1 is used in the factory settings for the SEL control OGIC equations circuit breaker status setting: Example 52A = Connect input IN1 to a 52a circuit breaker auxiliary contact.

  • Page 43: Local Control Switches

    The output of the local control switch in Figure 3.2 is a Relay Word bit (local bit LBn, n = 1–8). These local bits are used in SEL control equations. For OGIC a given local control switch, the local control switch positions are enabled by making corresponding label settings.

  • Page 44: Table 3.4 Correspondence Between Local Control Switch Types And Required Label Settings

    Interface. Additional Settings Other application ideas for local bits are: ➤ Examples ground relay enable/disable ➤ remote control supervision ➤ sequence coordination enable/disable Local bits can be applied to almost any control scheme. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 45: Remote Control Switches

    5.22). The output of the remote control switch in Figure 3.3 is a Relay Word bit (remote bit RBn, n = 1–8). These remote bits are used in SEL control OGIC equations. Any given remote control switch can be put in one of the following three positions: ➤...

  • Page 46: Instantaneous Overcurrent Elements

    (setting 79SKP). Control Equation Variables/Timers on page 3.38 to create OGIC definite-time overcurrent elements with SEL control equations OGIC (combining instantaneous overcurrent elements with timers.) Phase Instantaneous Six phase instantaneous overcurrent elements (50P1–50P6) are available (see...

  • Page 47: Figure 3.4 Phase Instantaneous Overcurrent Elements 50P1-50P6

    50C logic is the maximum phase C adaptive current algorithm. If 50ABCP = 35 A, the I input into 50A logic is the maximum phase A current output of cosine filter algorithm, the I input Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 48: Figure 3.5 Single-Phase Instantaneous Overcurrent Elements 50A, 50B, And 50C

    If pickup setting 50N1P is set to 50N1P = OFF, then element 50N1 is disabled. Relay Word bit 50N1 equals logical 0 at all times. The second neutral ground instantaneous overcurrent element (50N2) operates similarly. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 49: Figure 3.7 Residual Ground Instantaneous Overcurrent Elements 50G1 And 50G2

    If pickup setting 50Q1P is set to 50Q1P = OFF, then element 50Q1 is disabled. Relay Word bit 50Q1 equals logical 0 at all times. The second negative-sequence instantaneous overcurrent element (50Q2) operates similarly. Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 50: Time-Overcurrent Elements

    Setting 51P2TC Controls the Torque Control Switch OGIC Torque Control Setting 51P2TC State Switch Position 51P2RS = Reset Timing Logical 1 Closed Electromechanical Logical 0 Open 1 Cycle Figure 3.9 Phase Time-Overcurrent Elements 51P1T and 51P2T SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 51 51P1TC = logical 1; deassert local bit LB2 via the front- panel pushbuttons/display, resulting in 51P1TC = logical 0 Many other torque control setting ideas are available with the flexibility of control equations. OGIC Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 52 Applications for Time-Overcurrent Element Relay Word Bits Relay Relay Word Bit Word Application Definition 51P1 pickup indication Primarily for testing or other SEL control OGIC equation applications. See Trip Logic on page 3.17 (setting ULTR). See Reclosing Relay on page 3.22 (setting 79BRS).

  • Page 53: Figure 3.10 Neutral Ground Time-Overcurrent Element 51N1T

    Figure 3.11 for the residual ground time- overcurrent element (51G1T), follow the explanation given for Figure 3.9 the first phase time-overcurrent element (51P1T), substituting I for I like settings and Relay Word bits. Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 54: Figure 3.12 Negative-Sequence Time-Overcurrent Elements 51Q1T And 51Q2T

    (51Q1T and 51Q2T), follow the explanation given for Figure 3.9 for the first phase time-overcurrent element (51P1T), substituting for I and like settings and Relay Word bits. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 55: Trip Logic

    Relay Elements and Logic 3.17 Trip Logic Trip Logic The trip logic in Figure 3.13 provides flexible tripping with SEL control OGIC equation settings: TR . Trip Conditions ULTR . Unlatch Trip Conditions and setting: TDURD Minimum Trip Duration Time...
  • Page 56 RESET} pushbutton and the TAR R (Target Reset) serial port command is also available as Relay Word bit TRGTR. Factory Settings The factory settings for the trip logic SEL control equation settings are: OGIC 51P1T + 51G1T + 50P1*SH0 + LB3 (trip conditions)
  • Page 57 TRIP Relay Word bit deasserts to logical 0. Program an Output In the factory settings, the resultant of the trip logic in Figure 3.13 is routed to output contact OUT1 with the following SEL control equation: OGIC Contact for Tripping TRIP OUT1 = Output Contacts on page 3.39...

  • Page 58: Close Logic

    Relay Elements and Logic Close Logic Close Logic The close logic in Figure 3.14 provides flexible circuit breaker closing/auto reclosing with SEL control equation settings: OGIC (close conditions, other than automatic reclosing or CLOSE command) ULCL. (unlatch close conditions, other than breaker status, close failure, or...
  • Page 59 The circuit breaker closes (52A = logical 1), ➤ Or the reclose initiation condition (79RI) makes a rising edge (logical 0 to logical 1) transition. Factory Settings The factory settings for the close/reclose logic SEL control equation OGIC settings are: Example...

  • Page 60: Reclosing Relay

    3.14. The CLOSE Relay Word bit can be assigned to an output contact and provide automatic reclosing, in addition to closing via the CLOSE command or the SEL OGIC control equation setting CL. Up to four (4) automatic reclose attempts (shots) can be made.

  • Page 61: Table 3.5 Relay Word Bit And Front-Panel Correspondence To Reclosing Relay States

    Respectively)]. ➤ Open Command (OPE) is executed and SEL control OGIC equation setting 79RI = TRIP + …). [Early SEL-551 firmware versions do not have this feature (see Appendix A: Firmware and Manual Versions). To effectively incorporate this feature into these firmware versions, set SEL...
  • Page 62 Close Logic on page 3.20 for more discussion on SEL control equation settings 52A and CL. Also see OGIC Optoisolated Inputs on page 3.3 for more discussion on SEL control OGIC equation setting 52A. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 63: Figure 3.16 Reclosing Sequence From Reset To Lockout With Factory Settings

    79RSLD 300.000 reset time from lockout state The operation of these timers is affected by SEL control equation settings OGIC discussed later in this section. Also see the setting sheets in Section 4: Setting Relay.
  • Page 64 The setting of 79RSD and 79RSLD is independent (setting 79RSLD can even be set greater than setting 79RSD, if desired). SEL control equation OGIC...

  • Page 65: Table 3.6 Shot Counter Correspondence To Relay Word Bits And Open Interval Times

    1). Input IN1 is connected to a 52a breaker auxiliary contact and, thus, the circuit breaker has to be closed when the TRIP Relay Word bit asserts in order to initiate open interval timing. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 66 (79RI) includes input IN1, that is connected to a 52a breaker auxiliary contact. !IN1 79RI = If a 52b breaker auxiliary contact is connected to input IN1, the reclose initiate setting (79RI) would be set as follows: 79RI = SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 67 79DLS, Respectively) (see preceding discussions on last shot determination and the shot counter). NOTE : See OPE Command (Open) for a possible 79DTL setting for SEL-551 relays with early firmware versions. Factory Settings Example The drive-to-lockout factory setting is: 79DTL =...
  • Page 68 79DTL = 0 (numeral 0) 79DLS = With settings 79DTL and 79DLS inoperative, the SEL-551 will still end up in the Lockout State (and at last shot) if an entire automatic reclose sequence is unsuccessful. Overall, settings 79DTL or 79DLS are needed to take the SEL-551 to the Lockout State (or to last shot) for immediate circumstances.
  • Page 69 (79STL = logical 1 still), the 79SKP setting is still processed. Once the trip condition goes away (Relay Word bit TRIP = logical 0), open interval timing can proceed. Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 70: Figure 3.17 Voltage Relay (27/59) Provides Reclose Block Signal To Sel-551

    27/59 SEL-551 27/59 Figure 3.17 Voltage Relay (27/59) Provides Reclose Block Signal to SEL-551 The contact from the voltage relay indicates the presence or absence of voltage. If line voltage is present, open interval timing is stalled. If line voltage is not present, open interval timing proceeds.
  • Page 71 1. Thus, the factory 79BRS setting can function to block reset timing if time-overcurrent pickup 51P1 or 51G1 is picked up while the relay is in the Reclose Cycle State. This helps prevent repetitive “trip-reclose” cycling. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 72 This assertion/ deassertion indicates that a downstream device (e.g., line recloser—see Figure 3.18) has operated to clear a fault. Incrementing the shot counter keeps the SEL-551 “in step” with the downstream device, as is shown in the following Additional Settings Example 1 Additional Settings Example 2 on page 3.36.

  • Page 73: Figure 3.18 Sequence Coordination Between The Sel-551 And A Line Recloser

    Fault occurs beyond line recloser; w fault cleared by line recloser fast curve; e line recloser recloses into fault; r fault cleared by line recloser slow curve. Figure 3.19 Operation of SEL-551 Shot Counter for Sequence Coordination With Line Recloser (Additional Settings Example 1)
  • Page 74 3.36 Relay Elements and Logic Reclosing Relay If the SEL-551 is in the Reset State (79RS = logical 1) and then a permanent fault beyond the line recloser occurs (fault current I Figure 3.18), the line recloser fast curve operates to clear the fault. The SEL-551 also sees the fault.

  • Page 75: Figure 3.20 Operation Of Sel-351 Relay Shot Counter For Sequence Coordination With Line Recloser (Additional Setting Example 2)

    Refer to Figure 3.20. If the SEL-551 is in the Reset State (79RS = logical 0) with the shot counter reset (shot = 0; SH0 = logical 1) and then a permanent fault beyond the line recloser occurs (fault current I Figure 3.18), the line recloser fast curve...

  • Page 76: Sel Ogic Control Equation Variables/Timers

    Variable Timer examples make use of = 2 cycles). The output of the timer (Relay Word bit SV5T) operates output output contacts. Output Contacts on contact OUT3 (SEL-551 factory setting only). page 3.39 shows what output contacts are available in the SEL-551...

  • Page 77: Output Contacts

    (Breaker Failure SV7D0 Trip) 50P1 OUT3 50N1 OUT4 Figure 3.22 Dedicated Breaker Failure Scheme Created With SEL OGIC Variables/Timers Note that the above SEL control equation setting SV7 creates a seal-in OGIC logic circuit (as shown in Figure 3.22) by virtue of SEL...

  • Page 78: Figure 3.23 Logic Flow For Example Sel-551 Output Contact Operation

    OGIC Variables/Timers on page 3.38) 0 (output contact OUT4 not used-set to logical 0) OUT4 = Figure 1.2 shows the factory configuration of the output contacts for the SEL- 551 relay. Operation of Output Contacts for Different Output Contact Types...

  • Page 79: Demand Ammetering

    (energized or de-energized) and output contact types (a or b) are demonstrated. See Output Contact Jumpers (SEL-551 With the Conventional Terminal Blocks Option) on page 2.15 for output contact type options.

  • Page 80: Figure 3.24 Response Of Thermal Demand Ammeter To A Step Input (Setting Dmtc = 15 Minutes)

    3.42 Relay Elements and Logic Demand Ammetering The SEL-551 provides demand and peak demand ammetering for the following values: Currents Input currents (A primary) A,B,C,N Residual ground current (A primary; IG = 3I0 = IA + IB + IC) Negative-sequence current (A primary) These demand and peak demand values are thermal demand values.

  • Page 81: Table 3.7 Demand Ammeter Settings And Settings Range

    (bottom) is at 90 percent (0.9 per unit) of full applied value (1.0 per unit) after a time period equal to setting DMTC = 15 minutes, referenced to when the step current input is first applied. The SEL-551 updates thermal demand values approximately every two seconds. Demand Ammeter Table 3.7 Demand Ammeter Settings and Settings Range...

  • Page 82: Figure 3.26 Demand Current Logic Outputs

    51G1T. This is accomplished Pickup for Unbalance with the following settings from Table 3.7, pertinent residual ground Current overcurrent element settings, and SEL control equation torque control OGIC setting 51G1TC (see Figure 3.27). DMTC = GDEMP = 1.50...

  • Page 83: Figure 3.27 Raise Pickup Of Residual Ground Time-Overcurrent Element For Unbalance Current

    I G(DEM) below corresponding demand pickup GDEMP = 1.00 A secondary, and Relay Word bit GDEM is deasserted to logical 0. This results in SEL control OGIC equation torque control setting 51G1TC being in the state:...
  • Page 84 Figure 6.2. Demand Ammetering The SEL-551 updates demand values approximately every two seconds. Updating and Storage The relay stores peak demand values to nonvolatile storage once per day (it overwrites the previous stored value if it is exceeded). Should the relay lose control power, it will restore the peak demand values saved by the relay at 23:50 hours on the previous day.

  • Page 85: Front-Panel Target Leds

    Front-Panel Target LEDs Refer to Figure 2.5 for the arrangement of the target LEDs on the front panel of the SEL-551 relay. Table 3.8 SEL-551 Front-Panel Target LED Definitions Definition Relay Enabled—see subsection Relay Self-Tests on page 8.16 INST Instantaneous trip—see further details following Phase A involved in the fault—see further details following...
  • Page 86 (the TAR R serial port command can also be effectively operated via Modbus protocol, too—see Appendix G: Modbus RTU Communications Protocol). Relay Word bit TRGTR asserts to logical 1 for as long as the {TARGET RESET} pushbutton is pressed. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 87: Overview

    Settings Changes Via the Serial Port Section 5: Serial Port Communications and Commands for information on serial port communications and relay access levels. To change a specific setting, enter the command: SET n s Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 88: Time-Overcurrent Element Setting Reference Information

    Answer Y <Enter> to enable the new settings. For about one second, while the active settings are updated, the relay is disabled and the ALARM output contact closes for the SEL-551 (assuming b- type output contact; see Figure 3.23).

  • Page 89: Table 4.3 Equations Associated With U.s. Curves

    ⎠ • C4 (Long-Time Inverse) Figure 4.9 ⎝ ⎠ – – ⎛ 0.05 ⎞ ⎛ ⎞ 4.85 ---------------------- • ---------------- • ⎝ ⎠ C5 (Short-Time Inverse) Figure 4.10 ⎝ ⎠ 0.04 – – Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 90: Figure 4.1 U.s. Moderately Inverse Curve: U1

    3.00 30 (25) 2.00 15 (12.5) 1.00 6 (5) 0.50 3 (2.5) .5 .6 .7 .8 .9 1 5 6 7 8 9 Multiples of Pickup Figure 4.1 U.S. Moderately Inverse Curve: U1 SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 91: Figure 4.2 U.s. Inverse Curve: U2

    4.00 3.00 30 (25) 2.00 15 (12.5) 1.00 6 (5) 0.50 3 (2.5) .5 .6 .7 .8 .9 1 5 6 7 8 9 Multiples of Pickup Figure 4.2 U.S. Inverse Curve: U2 Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 92: Figure 4.3 U.s. Very Inverse Curve: U3

    30 (25) 4.00 3.00 15 (12.5) 2.00 1.00 6 (5) 0.50 3 (2.5) .5 .6 .7 .8 .9 1 5 6 7 8 9 Multiples of Pickup Figure 4.3 U.S. Very Inverse Curve: U3 SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 93: Figure 4.4 U.s. Extremely Inverse Curve: U4

    6.00 15 (12.5) 5.00 4.00 3.00 6 (5) 2.00 3 (2.5) 1.00 0.50 .5 .6 .7 .8 .9 1 6 7 8 9 Multiples of Pickup Figure 4.4 U.S. Extremely Inverse Curve: U4 Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 94: Figure 4.5 U.s. Short-Time Inverse Curve: U5

    30 (25) 8.00 6.00 5.00 15 (12.5) 4.00 3.00 2.00 6 (5) 1.00 3 (2.5) 0.50 .5 .6 .7 .8 6 7 8 9 Multiples of Pickup Figure 4.5 U.S. Short-Time Inverse Curve: U5 SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 95: Figure 4.6 Iec Class A Curve (Standard Inverse): C1

    30 (25) 0.20 15 (12.5) 0.10 0.05 6 (5) 3 (2.5) .5 .6 .7 .8 .9 1 5 6 7 8 9 Multiples of Pickup Figure 4.6 IEC Class A Curve (Standard Inverse): C1 Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 96: Figure 4.7 Iec Class B Curve (Very Inverse): C2

    15 (12.5) 0.50 0.40 0.30 6 (5) 0.20 3 (2.5) 0.10 0.05 .5 .6 .7 .8 .9 1 6 7 8 9 Multiples of Pickup Figure 4.7 IEC Class B Curve (Very Inverse): C2 SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 97: Figure 4.8 Iec Class C Curve (Extremely Inverse): C3

    0.80 0.70 0.60 3 (2.5) 0.50 0.40 0.30 0.20 0.10 0.05 .5 .6 .7 .8 .9 1 6 7 8 9 Multiples of Pickup Figure 4.8 IEC Class C Curve (Extremely Inverse): C3 Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 98: Figure 4.9 Iec Long-Time Inverse Curve: C4

    1500 (1250) 600 (500) 300 (250) 1.00 0.90 0.80 0.70 0.60 150 (125) 0.50 0.40 0.30 60 (50) 0.20 30 (25) 0.10 0.05 Multiples of Pickup Figure 4.9 IEC Long-Time Inverse Curve: C4 SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 99: Figure 4.10 Iec Short-Time Inverse Curve: C5

    15 (12.5) 0.70 0.60 0.50 0.40 6 (5) 0.30 0.20 3 (2.5) 0.10 0.05 .5 .6 .7 .8 .9 6 7 8 9 Multiples of Pickup Figure 4.10 IEC Short-Time Inverse Curve: C5 Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 100: Relay Word Bit Setting Reference Information

    TRGTR TAR 14 Row 0 used for front-panel LEDs and TAR command as shown in Table 5.6. Row 0 targets are not available for SEL control equations. OGIC Reserved for future use. Table 4.6 Relay Word Bit Definitions (Sheet 1 of 4)
  • Page 101 Optoisolated input IN2 asserted (see Figure 3.1) Asserts 1/8 cycle for Open Command execution (see Figure 3.13) Asserts 1/8 cycle for Close Command execution (see Figure 3.14) Close Failure logic output asserted (see Figure 3.14) Indication Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 102 Reclosing relay shot counter = 1 (see Table 3.6) Reclosing relay shot counter = 2 (see Table 3.6) Reclosing relay shot counter = 3 (see Table 3.6) Reclosing relay shot counter = 4 (see Table 3.6) SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 103 The Open Command (Relay Word Bit OC) and Close Command (Relay Word Bit CC) are already embedded in the Trip Logic (see Figure 3.13) and Close Logic (see Figure 3.14), respectively. Thus, they are likely not used in SEL control equations. They are in the Relay Word for OGIC embedded event report information functions (see Table 7.3).

  • Page 104: Settings Explanations

    (1 + X/R) times the burden voltage for the maximum symmetrical fault current, where X/R is the reactance-to-resistance ratio of the primary system. Use caution when selecting CTs for saturation conditions in the SEL-551 firmware revisions prior to SEL-551-R507-Vf Z001001-D20020828 and SEL-551-R108-Vr Z001001 D20020828 (see...
  • Page 105 = the total CT secondary burden in ohms ANSI = the ANSI voltage classification of CTs An SEL-551 phase instantaneous overcurrent element is to be set at 80 amps. The relay will be used with a C400, 400:5 current transformer with a 0.50 W ohm total burden.

  • Page 106: Settings Sheets

    The calculation shows that the 400:5 (class C400) CT meets the criteria in Equation 4.1. Other System The relay settings NFREQ and PHROT allow you to configure the SEL-551 to your specific system. Parameters ➤ Set NFREQ equal to your nominal power system frequency, either 50 Hz or 60 Hz.

  • Page 107: Settings Sheets For The Sel-551 Relay

    Date _______________ Settings Sheets for the SEL-551 Relay SET.1 of 12 Relay Settings (SET Command) Settings Sheets for the SEL-551 Relay Relay Settings (SET Command) Identifier Labels (see Settings Explanations on page 4.18) Relay Identifier (12 characters) Terminal Identifier (12 characters)
  • Page 108 SET.2 of 12 Settings Sheets for the SEL-551 Relay Date________________ Relay Settings (SET Command) Single-Phase Instantaneous Overcurrent Elements 50A, 50B, 50C (see Figure 3.5) Pickup (OFF, 0.5–80.0 A in 0.1 A increments) (5 A nominal) (OFF, 0.1–16.0 A in 0.1 A increments) (1 A nominal)
  • Page 109 Date _______________ Settings Sheets for the SEL-551 Relay SET.3 of 12 Relay Settings (SET Command) Curve (U1–U5, C1–C5; see Figure 4.1–Figure 4.10) 51N1C Time Dial 0.50–15.00 for curves U1–U5 0.05–1.00 for curves C1–C5 51N1TD Electromechanical Reset (Y, N) 51N1RS Residual Ground Instantaneous Overcurrent Elements 50G1, 50G2...
  • Page 110 SET.4 of 12 Settings Sheets for the SEL-551 Relay Date________________ Relay Settings (SET Command) Negative-Sequence Time Overcurrent Element 51Q1T (see Figure 3.12) IMPORTANT: See Appendix F: Setting Negative-Sequence Overcurrent Elements for information on setting negative-sequence overcurrent elements. Pickup (OFF, 0.5–16.0 A in 0.1 A increments) (5 A nominal) (OFF, 0.1–3.2 A in 0.1 A increments) (1 A nominal)
  • Page 111 Date _______________ Settings Sheets for the SEL-551 Relay SET.5 of 12 Relay Settings (SET Command) Close Failure Timer (see Figure 3.14) Close Failure Time (0–54000 cycles in 0.125 cycle increments) Demand Ammetering Settings (see Figure 3.24 Figure 3.26) Time Constant (5, 10, 15, 30, 60 minutes)
  • Page 112 SET.6 of 12 Settings Sheets for the SEL-551 Relay Date________________ Control Equation Settings (SET L Command) OGIC SV13 Pickup Time (0–54000.000 cycles in 0.125-cycle steps) SV13PU SV13 Dropout Time (0–54000.000 cycles in 0.125-cycle steps) SV13DO SV14 Pickup Time (0–54000.000 cycles in 0.125-cycle steps) SV14PU SV14 Dropout Time (0–54000.000 cycles in 0.125-cycle steps)
  • Page 113 Date _______________ Settings Sheets for the SEL-551 Relay SET.7 of 12 Control Equation Settings (SET L Command) OGIC Reclosing Relay (see Reclosing Relay on page 3.22) Reclose Initiate 79RI Reclose Initiate Supervision 79RIS Drive to Lockout 79DTL Drive to Last Shot...
  • Page 114 SET.8 of 12 Settings Sheets for the SEL-551 Relay Date________________ Text Settings (SET T Command) Output Contacts (see Figure 3.23) Output Contact OUT1 OUT1 Output Contact OUT2 OUT2 Output Contact OUT3 OUT3 Output Contact OUT4 OUT4 Display Points (see Rotating Default Display on page 6.11)
  • Page 115 Date _______________ Settings Sheets for the SEL-551 Relay SET.9 of 12 Text Settings (SET T Command) Local Bit LB4 Name (14 characters) NLB4 Clear Local Bit LB4 Label (7 characters) CLB4 Set Local Bit LB4 Label (7 characters) SLB4 Pulse Local Bit LB4 Label (7 characters)
  • Page 116 SET.10 of 12 Settings Sheets for the SEL-551 Relay Date________________ Port Settings (SET P Command and Front Panel) Display if DP6 = logical 1 (16 characters) DP6_1 Display if DP6 = logical 0 (16 characters) DP6_0 Display if DP7 = logical 1 (16 characters)
  • Page 117 24 Relay Word bits delimited by spaces or commas. See Sequential Events Recorder (SER) Event Report on page 7.8. Relay Word bits for the SEL-551 in Row 13 of Table 4.5 cannot be used in the following SER NOTE: settings.
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  • Page 119: Section 5: Serial Port Communications And Commands

    Commands Overview The SEL-551 Relay is equipped with a serial communications port on the rear panel of the relay. Connect the serial port to a computer serial port for local communications or to a modem for remote communications. Other devices useful for communications include the SEL-2032, the SEL-2030, or the SEL-2020 Communications Processor.
  • Page 120 SHIELD –IRIG-B –IRIG-B –RX SHIELD Main board jumper JMP14 in the SEL-551 relay (see Section 2: Installation). The following cable diagrams show several types of EIA-232 serial communications cables. These and other cables are available from SEL. Contact the factory for more information.
  • Page 121 Pin # Pin # Func. Func. TXD (IN) DTR (IN) RXD (OUT) CD (OUT) **DCE = Data Communications Equipment (Modem, etc.) SEL-551 to SEL PRTU Cable SEL-C231 SEL-PRTU SEL-551 Relay 9-Pin Male 9-Pin Male Round Conxall "D" Subconnector Func. Pin # Pin # Func.

  • Page 122: Communications Protocol

    Serial communications with the relay includes hardware and software protocols. Hardware Protocol SEL-551 relays equipped with an EIA-232 port support RTS/CTS hardware handshaking. RTS/CTS handshaking is not supported on relays equipped with just the EIA-485 port. To enable hardware handshaking, use the SET P command (or front-panel {SET} pushbutton) to set RTS_CTS = Y.
  • Page 123 ASCII, SEL LMD, or Modbus RTU protocol for the given port. SEL Fast Meter and SEL Compressed ASCII commands are always active for the given port if the corresponding protocol is SEL ASCII or LMD. SEL Fast Meter and SEL Compressed ASCII are not available on the port if the protocol is Modbus RTU.

  • Page 124: Table 5.2 Communications Settings

    CAN: <Ctrl+X> (hold down the Control key and press X) SEL Distributed Port Switch Protocol (LMD) The SEL LMD Protocol permits multiple SEL relays to share a common communications channel. The protocol is selected by setting the port setting PROTOCOL = LMD. See Appendix C: SEL Distributed Port Switch Protocol for more information on SEL LMD protocol.

  • Page 125: Serial Port Automatic Messages

    Serial Port Automatic Messages Table 5.2 Communications Settings (Sheet 2 of 2) Field Description Screen Name Range Default PROTOCOL = LMD Port Protocol PROTOCOL SEL, LMD, MOD LMD Prefix PREFIX @, #, $, %, & LMD Address ADDRESS 1–99 LMD Settling Time SETTLE_TIME 0–30 seconds...

  • Page 126: Serial Port Access Levels

    ➤ Access Level 2 (the highest access level) ➤ Access Level C (restricted access level, should be used under direction of SEL only) Access Level 0 Once serial port communications are established with the relay, the following prompt appears: This is referred to as Access Level 0. The only commands that can be executed...
  • Page 127 5.4). Access Level C The CAL access level is intended for use by the SEL factory, and for use by SEL field service personnel to help diagnose troublesome installations. A list of commands available at the CAL level is available from SEL upon request.

  • Page 128: Table 5.4 Serial Port Command Summary

    This is the RID setting (the relay is shipped with the default setting RID = FEEDER 1; see Identifier Labels on page 4.18). STATION A: This is the TID setting (the relay is shipped with the default setting TID = STATION A; see Identifier Labels). SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 129: Table 5.5 Acc And 2Ac Commands

    Access Level Attempt (Password Required). Assume the following conditions exist: ➤ main board password ➤ jumper JMP22 = off (passwords required to enter higher access levels) ➤ Access level = 0 (prompt Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 130 Access Level 1. The relay responds: FEEDER 1 Date: 03/05/96 Time: 08:31:10.361 STATION A Level 1 => prompt indicates that the relay is now in Access Level 1. => SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 131 TRIP type of event. For more information on events and event reports, see Section 7: Standard Event Reports and SER. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 132 A-phase current in primary amps B-phase current in primary amps C-phase current in primary amps Measured neutral ground current in primary amps Calculated residual current in primary amps 3I2: Calculated negative-sequence current in primary amps SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 133 Serial Port Communications and Commands 5.15 Command Explanations The SEL-551 reports the phase angles referenced to IA (IA phase angle = 0, positive phase angles leading). To view instantaneous metering values, enter the command: =>MET n <Enter> where n is an optional parameter to specify the number of times to repeat the meter display.
  • Page 134 Access Level 0. The QUI command remaps the front-panel targets to the Relay Targets (TAR 0) and terminates the SEL LMD connection if it is established (see Appendix C: SEL Distributed Port Switch Protocol).
  • Page 135 79BRS =(51P1 + 51G1) * (79RS + 79CY) 79SEQ =0 =51P1 + 51G1 =SV5T + CF =TRIP SV10 SV11 SV12 SV13 SV14 OUT1 =TRIP OUT2 =CLOSE OUT3 =SV5T OUT4 Press RETURN to continue <Enter> =LB1 =IN1 Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 136 N = a number (N = 1, 2, 3, ...) that specifies the number of times to repetitively display the status report. If no number is entered after the STA command, the relay displays the status report only once. SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 137 To reset the self-test statuses, use the STA C command from Access Level 2: =>>STA C <Enter> The relay responds: Reboot the relay and clear status Are you sure (Y/N) ? Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 138 If the TAR command is executed from the front panel (see Figure 6.3), front- panel timeout is 15 minutes of front-panel keyboard inactivity. Front-panel timeout takes the targets back to their normal front-panel target operation, also (like TAR 0). SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 139: Table 5.6 Sel-551 Relay Word And Its Correspondence To Tar Command And Front-Panel Leds

    Serial Port Communications and Commands 5.21 Command Explanations Table 5.6 SEL-551 Relay Word and Its Correspondence to TAR Command and Front-Panel LEDs TAR 0 (Front- INST Panel LEDs) TAR 1 51P1 51P2 51N1 51G1 51P1T 51P2T 51N1T 51G1T TAR 2...
  • Page 140 =>>CON 5 <Enter> CONTROL RB5: PRB 5 <Enter> =>> You must enter the same remote bit number in both steps in the command. If the bit numbers do not match, the relay responds: Invalid Command SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 141: Table 5.7 Sel-551 Control Subcommands

    Serial Port Communications and Commands 5.23 Command Explanations Table 5.7 SEL-551 Control Subcommands Subcommand Description SRB n Set Remote Bit n (“ON” position) CRB n Clear Remote Bit n (“OFF” position) PRB n Pulse Remote Bit n for one processing interval (1/8 cycle;...

  • Page 142: Table 5.8 Valid Password Characters

    =>> PUL Command (Pulse) The PULSE command allows you to pulse any of the output contacts for a specified length of time. The command format is: PUL X Y SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 143 Table 4.1). VER Command (Show Relay Configuration and Firmware Version) The VER command provides relay configuration and information such as nominal current input ratings. An SEL-551 example printout of the VER command follows: =>>VER <Enter> FID=SEL-551-R500-Vf-Z001001-D20050124 CID=D07F Part Number: 055100BX5X4X...
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  • Page 145: Sel-551 Command Summary

    SEL-551 Command Summary Access Level 0 The only thing that can be done at Access level 0 is to go to Access Level 1. The screen prompt is: = Command Enters Access Level 1. If the main board password jumper is not in place, the relay prompts for the entry of the Access Level 1 password in order to enter Access Level 1.

  • Page 146: Command Summary

    Enter Access Level C. If the main board Access jumper is not in place, the relay prompts for the entry of the Access Level C password. Access Level C is reserved for SEL use only. Assert the CLOSE Relay Word bit. If CLOSE is assigned to an output contact (e.g., OUT2 = CLOSE), then the output contact will assert if command CLO is executed and the circuit breaker is open.

  • Page 147: Section 6: Front-Panel Interface

    Primary Function Function q Secondary q See Figure 6.3. Figure 6.1 SEL-551 Front-Panel Pushbuttons—Overview Primary Functions Note in Figure 6.2 Figure 6.3 that the front-panel pushbutton primary functions have correspondence to serial port commands—both retrieve the same information or perform the same function. To get more detail on the...

  • Page 148: Figure 6.2 Sel-551 Front-Panel Pushbuttons-Primary Functions

    Front-panel pushbutton functions that correspond to Access Level 1 serial port commands do not require the entry of the Access Level 1 password through the front panel. Figure 6.2 SEL-551 Front-Panel Pushbuttons—Primary Functions Front-Panel Password Security Refer to the comments at the bottom of Figure 6.3...

  • Page 149: Figure 6.3 Sel-551 Front-Panel Pushbuttons-Primary Functions (Continued)

    Output contacts are pulsed for only one second from the front panel. r Local control is not available through the serial port and does not require the entry of a password. Figure 6.3 SEL-551 Front-Panel Pushbuttons-Primary Functions (continued) Secondary Functions After a primary function is selected (see Figure 6.2...

  • Page 150: Functions Unique To The Front-Panel Interface

    Setting Digit The front-panel display gives indication of the arrow button to use (Displays symbols: ← → ↑ ↓) Figure 6.4 SEL-551 Front-Panel Pushbuttons-Secondary Functions Functions Unique to the Front-Panel Interface Two front-panel primary functions do not have serial port command equivalents.
  • Page 151 (RS LED on front panel is illuminated), RECLOSE COUNT = 0. If the breaker is open and the reclosing relay is locked out after a reclose sequence (LO LED on front panel is illuminated), RECLOSE COUNT = 2. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 152 If the relay trips the breaker open again, the reclosing relay goes to the lockout state (front-panel LO LED illuminates). The reclosing relay shot counter screen still appears as: SET RECLOSURES=2 RECLOSE COUNT =2 SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 153: Figure 6.5 Local Control Switch Configured As An On/Off Switch

    In more specific terms, local control asserts (sets to logical 1) or deasserts (sets to logical 0) what are called local bits LB1–LB8. These local bits are OGIC ® available as Relay Word bits and are used in SEL control equations (see Table 4.5 Table 4.6).
  • Page 154 There are no more local control switches in the factory default settings. Press the right arrow pushbutton, and scroll to the Output Contact Testing function: Output Contact ←→ Testing This front-panel function provides the same function as the serial port PULSE command (see Figure 6.3). SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 155 Scroll left with the left arrow button and then select . The display then shows the new local control switch position: Relay MANUAL TRIP Word MANUAL TRIP RETURN Logical 1 (Logical 0) Position: TRIP TRIP Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 156 If the reclosing switch is in the enable position (switch closed) before the power outage, it will be in the same position after the outage when power is restored. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 157: Rotating Default Display

    PULLMAN WASHINGTON USA If display point labels are also enabled for display, the Press CNTRL for displays for two seconds and then is followed by enabled Local Control display point labels in subsequent two-second rotations. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 158 Local Control Switches on page 3.5). Optoisolated input IN1 is used as a circuit breaker status input (a 52a circuit breaker auxiliary contact is connected to input IN1; see Optoisolated Inputs on page 3.3). SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 159 DP2 = LB1 = logical 0 DP2_0 = 79 DISABLED FAULT TYPE DP4_1 = BREAKER CLOSED 79 DISABLED BREAKER CLOSED DP4 = IN1 = logical 1 DP4_0 = BREAKER OPEN SCHWEITZER ENGINEE PULLMAN WASHINGTON USA Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 160 Display point label settings are set with the SET T command or viewed with the SHOWSET T command via the serial port [see Section 4: Setting the Relay SHO Command (Showset) on page 5.16]. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 161: Section 7: Standard Event Reports And Ser

    Section 7 Standard Event Reports and SER Overview The SEL-551 Relay has two styles of event reports: ➤ Standard 15-cycle event reports ➤ Sequential events recorder (SER) event report These event reports contain date, time, current, relay element, optoisolated input, and output contact information.
  • Page 162 If 51G1 remains asserted and then a short time later 51P1 asserts, a second report will not be generated for the assertion of 51P1. ER1 is already at logical 1 because of the initial assertion of 51G1. Rising-edge or falling-edge detects can be used in making SEL settings. OGIC This is particularly useful in these event report trigger settings ER1 and ER2.

  • Page 163: Figure 7.1 Example Event Summary

    The possible event types and their Event: descriptions are shown in the table below. Note the correspondence to the preceding event report triggering conditions (see Standard Event Report Triggering on page 7.1). Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 164: Table 7.1 Event Types

    If no numeric n parameter is entered with the serial port command, the most recent event report (n = 1) is displayed. If an event report is requested which does not exist, the relay responds: Invalid Event SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 165: Table 7.2 Standard Event Report Current Columns

    Figure 7.4 shows how event report current column data can be converted to phasor rms current values. Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 166: Table 7.3 Other Standard Event Report Columns

    Residual ground instantaneous overcurrent element 50G2 picked up. Both 50G1 and 50G2 picked up. 50 Q12 50Q1, 50Q2 Negative-sequence instantaneous overcurrent element 50Q1 picked up. Negative-sequence instantaneous overcurrent element 50Q2 picked up. Both 50Q1 and picked up. SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 167 Both RB7 and RB8 asserted Rem OC OC, CC OPEN command executed CLOSE command executed SELogic Var 12 SV1, SV2 Variable SV1 asserted OGIC Variable SV2 asserted OGIC Both SV1 and SV2 asserted Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 168: Sequential Events Recorder (Ser) Event Report

    SELogic Var 12T SV12, SV12T remains asserted while timer timing on dropout time. SELogic Var 13T SV13, SV13T SELogic Var 14T SV14, SV14T Table 7.4 SEL-551 Input/Output Event Report Columns Corresponding Elements Column Heading Symbol Definition (Relay Word Bits) Out 12...

  • Page 169: Table 7.5 Ser Report Row Commands And Format

    They display with the oldest row (row 17) at the beginning (top) of the report and the latest row (row 1) at the end (bottom) of the report. Chronological progression through the report is down the page and in descending row number. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 170 If there are no rows in the SER event report buffer, the relay responds: No SER data Clearing SER Event If the SER C command is entered, the relay prompts the operator for confirmation: Report Buffer Clear SER Buffer Are you sure (Y/N)? SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 171: Example Standard 15-Cycle Event Report

    Example Standard 15-Cycle Event Report The following example SEL-551 standard 15-cycle event report in Figure 7.2 also corresponds to the example sequential events recorder (SER) event report Figure 7.5.
  • Page 172 -2 ...r..C0 1..p..1... -1 ...r..C0 1..p..1... 1 ...r..C0 1..p..1... 1 ...r..C0 1..p..1... 3 ..... C0 1..p..1... (Continued on next page) SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 173 51P1P = 6.0 51P1C = U3 51P1TD= 3.00 51P1RS= N 51P2P = OFF 51P2C = U3 51P2TD= 15.00 51P2RS= N Relay and SEL Control 50N1P = OFF 50N2P = OFF OGIC 51N1P = OFF 51N1C = U3 51N1TD= 15.00 51N1RS= N...

  • Page 174: Figure 7.2 Example Sel-551 Standard 15-Cycle Event Report (1/8-Cycle Resolution)

    Example Standard 15-Cycle Event Report (Continued from previous page) =LB1 =IN1 =>> Figure 7.2 Example SEL-551 Standard 15-Cycle Event Report (1/8-Cycle Resolution) Figure 7.3 Figure 7.4 look in detail at 1 cycle of phase A (channel IA) current identified in Figure 7.2.

  • Page 175: Figure 7.3 Derivation Of Event Report Current Values And Rms Current Values From Sampled Current Waveform

    Figure 7.3 Derivation of Event Report Current Values and RMS Current Values From Sampled Current Waveform Figure 7.3, note that any two rows of current data from the event report in Figure 7.2, one quarter (1/4) cycle apart, can be used to calculate rms current values. Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 176: Figure 7.4 Derivation Of Phasor Rms Current Values From Event Report Current Values

    X = 70 Real Axis –2274 Angle = Arctan = Arctan = –88.24° Magnitude = (–2274) + (70) = 2275 Figure 7.4 Derivation of Phasor RMS Current Values From Event Report Current Values SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 177: Example Sequential Events Recorder (Ser) Event Report

    2275 A • cos(–88.24°) = 70 A Example Sequential Events Recorder (SER) Event Report The following example SEL-551 sequential events recorder (SER) event report in Figure 7.5 also corresponds to the example standard 15-cycle event report in Figure 7.2.
  • Page 178 Output contact OUT1 deasserts (.) after being asserted a minimum of 9 cycles. Related settings: TDURD = 9.000 cycles TRIP OUT1 = Time difference: 13:45:45.089 – 13:45:44.939 = 0.150 seconds (= 9 cycles) SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 179: Section 8: Testing And Troubleshooting

    Maintenance Testing on page 8.15 should be used for determining and establishing test routines for the SEL-551 Relay. Included are discussions on testing philosophies, methods, and tools. Example test procedures are shown for the overcurrent elements, differential elements, and metering. Relay troubleshooting procedures are shown at the end of the section.

  • Page 180: Figure 8.1 Low-Level Test Interface

    (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 9 V peak-to-peak to the low-level test interface.
  • Page 181 SER2, or SER3 setting. Whenever an element asserts or deasserts, a time stamp is recorded. Step 3. View the SER report with the SER command. Step 4. Clear the SER report with the SER C command. Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 182: Acceptance Testing

    What to test: All protection elements and logic functions critical to the intended application. SEL performs detailed acceptance testing on all new relay models and versions. We are certain the relays we ship meet their published specifications. It is important for you to perform acceptance testing on a relay if you are unfamiliar with its operating theory, protection scheme logic, or settings.

  • Page 183: Figure 8.2 Relay Part Number And Hardware Identification Sticker

    Connect a computer terminal to the serial port of the relay. Communication Parameters: 2400 Baud, 8 Data Bits, 1 Stop Bit, N Parity Cables: SEL C234A for 9-pin male computer connections, SEL C227A for 25-pin male computer connections Step 2. Purpose: Apply control voltage to the relay, and start Access Level 0 communications.
  • Page 184 The relay is shipped with factory settings; type SHO <Enter> to view the settings. Section 4: Setting the Relay includes a complete description of the settings. The terminal display should look similar to the following: SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 185 Set the target LEDs to display the contact inputs by typing TAR 4 <Enter>. The fourth and fifth front- panel LED should now follow logic inputs IN1 and IN2, which are in Relay Word Row 4.2. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 186 If IG equals approximately 3 times the applied current, then all three phases have the same angle. If 3I2 equals approximately 3 times the applied current, then the phase rotation is reversed. b. Turn the current sources off. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 187: Figure 8.3 Test Connections For Balanced Load With Three-Phase Current Sources

    Display the appropriate Relay Word bit on the front-panel LEDs. Method: a. Execute the TARGET command (i.e., TAR 2 <Enter>). The SEL-551 now displays the state of several overcurrent elements on the front-panel LED and LCD display. Date Code 20110408 Instruction Manual...

  • Page 188: Table 8.1 Instantaneous Overcurrent Elements And Corresponding Settings/Relay Word Bits/Tar Commands

    Neutral Ground Level 1 50N1P 50N1 Neutral Ground Level 2 50N2P 50N2 Residual Ground Level 1 50G1P 50G1 Residual Ground Level 2 50G2P 50G2 Negative-Sequence Level 1 50Q1P 50Q1 Negative-Sequence Level 2 50Q2P 50Q2 SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 189 Verify the operation times. Method: a. Type SER <Enter> to view the sequential event records. The assertion and deassertion of each element listed in the SER 1, 2, and 3 settings is recorded. Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 190: Table 8.2 Inverse-Time Overcurrent Elements And Corresponding Settings/Relay Word Bits/Tar Commands

    51G1 Pickup 51G1P (picked up) Curve 51G1C Time-Dial 51G1TD 51G1T Electromechanical Reset 51G1RS (timed out) Negative-Sequence Level 1 51Q1 Pickup 51Q1P (picked up) Curve 51Q1C Time-Dial 51Q1TD 51Q1T Electromechanical Reset 51Q1RS (timed out) SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 191 These tests were previously outlined in this section. Neutral Ground The SEL-551 has four neutral ground overcurrent elements. They all operate based on a comparison between the separate neutral current input (IN) and the Overcurrent Elements neutral ground overcurrent setting.

  • Page 192: Commissioning Testing

    Testing and Troubleshooting Commissioning Testing Residual Ground The SEL-551 has four residual ground overcurrent elements. They all operate based on a comparison between a residual calculation of the three-phase Overcurrent Elements inputs and the residual ground overcurrent setting. The residual calculation...

  • Page 193: Maintenance Testing

    It is not necessary to verify operating characteristics as part of maintenance checks. At SEL, we recommend that maintenance tests on SEL relays be limited under the guidelines provided above. The time saved may be spent analyzing event data and thoroughly testing those systems that require more attention.

  • Page 194: Relay Self-Tests

    0.2 seconds. Failure +2.10 V Pulsed +6.00 V TEMP Warning –40° C Measures the temperature at the +85° C A/D voltage reference every 0.2 seconds. Failure –50° C Latched +100° C SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 195: Relay Troubleshooting

    0.2 seconds. The following self-tests are performed by dedicated circuitry in the microprocessor and the SEL-551 main board. Failures in these tests shut down the microprocessor and are not shown in the STATUS report.

  • Page 196: Relay Calibration

    Failed relay self-test. Relay Calibration The SEL-551 is factory-calibrated. If you suspect that the relay is out of calibration, please contact the factory. Factory Assistance We appreciate your interest in SEL products and services. If you have any questions or comments, please contact us at: Schweitzer Engineering Laboratories, Inc.

  • Page 197: Table A.1 Firmware Revision History

    Manual update only (see Table A.2). 20070709 ➤ SEL-551-R512-Vf-Z002002-D20070301 Fixed potential conflict between simultaneous Fast Operate 20070301 requests through Port 1 and the front panel. ➤ Repaired Compressed Event report format to restore SEL-5601 compatibility. Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 198: Appendix A: Firmware And Manual Versions Firmware

    ➤ SEL-551-R509-Vf-Z002002-D20050124 Password security enhancement. 20050124 ➤ OGIC ® Rising-edge and falling-edge detect operators in SEL control equations. ➤ Torque control setting equations for overcurrent elements can no longer be set directly to logical 0. ➤ Relay Word bit TRGTR (Target Reset output).

  • Page 199: Instruction Manual

    Corrected use of the “^” character in the SET command. SEL-551-R101-Vr-D960322 Initial version. Information about changes to earlier versions of the SEL-551 Instruction Manual is not available. Instruction Manual The date code at the bottom of each page of this manual reflects the creation or revision date.
  • Page 200 Added the 110 Vdc option to Optoisolated Inputs information in Specifications. 20070709 Overall, manual updated for splitting the SEL-551 manual from the SEL-551C manual. This manual now is for the SEL-551. A separate manual has been created for the SEL-551C relays.
  • Page 201 Summary of Revisions Section 4 ➤ Removed the separate Relay Word bit table for the SEL-551C, showing Relay Word bits IN1–IN6 and OUT1– OUT3 for the new digital I/O mix and latch bit outputs LT1–LT8. ➤ Removed programmable software and hardware alarm Relay Word bits SALARM and HALARM, respec- tively, for the SEL-551C.
  • Page 202 20050523 ➤ Updated for firmware version R110/R510. 20050120 Overall, manual updated for new relay model SEL-551C. The manual now is a combined, dual manual for both the SEL-551 and the SEL-551C relays. Section 1 ➤ Listed major differences for the new SEL-551C, compared to the SEL-551.
  • Page 203 Appendix E ➤ Added Compressed ASCII command responses for the SEL-551C. Appendix G ➤ Added new Modbus updates for the new SEL-551C, primarily because of the new digital I/O mix and target LED rearrangement. Section 1 20030905 ➤ Modified text in CT Saturation Protection.
  • Page 204 Added Tightening Torque information to General Specifications. ➤ Updated Power Supply specification. Section 2 ➤ Updated Figure 2.7: SEL-551 Relay Rear Panel (Plug-In Connectors Option). ➤ Added caution note to the Clock Battery subsection. Appendix G ➤ Added clarification to Command Code 10 in Table G.16: Modbus Command Codes.
  • Page 205 Removed first settings example for settings 79RI and 79RIS [see Reclose Initiate and Reclose Initiate Supervision Settings (79RI and 79RIS, Respectively)]. ➤ Replaced second settings example for setting 79SEQ [see Sequence Coordination (79SEQ)]. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 206 Increased the number of digital banks in the A5C1 message. ➤ Added demand meter Relay Word bits to the Compressed ASCII DNA command. Information about changes to earlier versions of the SEL-551 Instruction Manual is not available. SEL-551 Relay Instruction Manual...
  • Page 207 (IC) component, and reassemble the relay. If you do not wish to perform the installation yourself, SEL can assist you. Simply return the relay and IC to SEL. We will install the new IC and return the unit to you within a few days.

  • Page 208: Appendix B: Firmware Upgrade Instructions Eprom Firmware Upgrades

    SHO, SHO L, SHO P, SHO R, and that you return the relay to SEL for SHO T. firmware installation. Normally, the relay will preserve the settings during the firmware upgrade.

  • Page 209: Figure B.2 Insertion Of The Extraction Tool In The Eprom Socket

    Step 20. Replace the relay front panel. Step 21. Replace the rear-panel communications cable. Step 22. With breaker control disabled, turn relay power on. Step 23. If the EN LED is illuminated, proceed to Step 10 below. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 210 Step 4. If the EPROM is seated properly and the relay will not power up, remove the EPROM and inspect it for bent pins. Step 5. If EPROM pins are bent, contact the SEL factory for a replacement. If the relay front panel displays a...

  • Page 211: Flash Firmware Upgrades

    PC, even though everything is OK. Step 8. From Access Level 2, issue the L_D <Enter> command to the relay (L underscore D <Enter>) to start the SEL program. BOOT Step 9. Type Y <Enter> at the Disable relay to send or receive prompt and Y <Enter>...
  • Page 212 NOTE: If the relay power fails during respond: a firmware receive after the old firmware is erased, the relay will restart in SEL , but the baud rate BOOT Download completed successfully! will default to 2400 baud. (If this happens, connect to the relay at 2400 baud and type BAUD 38400 at the prompt.
  • Page 213 Step 29. Issue the Trigger (TRI) and Event (EVE) commands. Step 30. Verify that the current and voltage signals are correct in the event report. The relay is now ready for your commissioning procedure. Date Code 20110408 Instruction Manual SEL-551 Relay...
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  • Page 215: Appendix C: Sel Distributed Port Switch Protocol

    SEL Distributed Port Switch Protocol Overview SEL Distributed Port Switch Protocol (LMD) permits multiple SEL relays to share a common communications channel. It is appropriate for low-cost, low- speed port switching applications where updating a real-time database is not a requirement.
  • Page 216 SEL Distributed Port Switch Protocol Operation 5. The QUIT command terminates the connection. If no data are sent to the relay before the port time-out period, it automatically terminates the connection. 6. Enter the sequence <Ctrl+X> QUIT <CR> before entering the prefix character, if all relays in the multidrop network do not have the same prefix setting.

  • Page 217: Appendix D: Configuration, Fast Meter, And Fast Operate Commands

    Fast Operate Commands Overview SEL relays have two separate data streams that share the same serial port. The human data communications with the relay consist of ASCII character commands and reports that are intelligible to humans using a terminal or terminal emulation package.

  • Page 218: Message Definitions

    In response to the A5C0 request, the relay sends the following block: Block Table D.3 A5C0 Relay Definition Block Data Description A5C0 Command Length Support two protocols, SEL and LMD Support three Fast Meter messages Three status flag commands A5C1 Fast Meter configuration command A5D1 Fast Meter command A5C2...
  • Page 219 Configuration, Fast Meter, and Fast Operate Commands Message Definitions Table D.4 A5C1 Fast Meter Configuration Block (Sheet 2 of 2) Data Description Four analog input channels Four samples per channel Fifteen digital banks (SEL-551) One calculation block 000C Analog channel offset 002C Time stamp offset 0034...

  • Page 220: Table D.5 A5D1 Fast Meter Data Block

    IA, IB, IC, IN 8-bytes Time stamp 15-bytes SEL-551 Relay Word bits (see DNA message for bit map) checksum 1-byte checksum of all preceding bytes A5C2/A5C3 Demand/ In response to the A5C2 or A5C3 request, the relay sends the following fast...

  • Page 221: Table D.7 A5D2/A5D3 Demand/Peak Demand Fast Meter Message

    A5B9 Fast Meter In response to the A5B9 request, the relay clears the Fast Meter (message A5D1) Status Byte. The SEL-551 Status Byte contains one active bit, STSET Status Acknowledge (bit 4). The bit is set on power up and on settings changes. If the STSET bit is Message set, the external device should request the A5C1, A5C2, and A5C3 messages.

  • Page 222: Table D.8 A5Ce Fast Operate Configuration Block

    Operate code, set remote bit RB7 Operate code, pulse remote bit RB7 Operate code, clear remote bit RB8 Operate code, set remote bit RB8 Operate code, pulse remote bit RB8 Reserved checksum 1-byte checksum of all preceding bytes SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 223: Table D.9 A5E0 Fast Operate Remote Bit Control

    The relay performs the specified breaker operation if the following conditions are true: ➤ Conditions 1–5 defined in the A5E0 message are true. ➤ The BREAKER jumper is in place on the SEL-551 main board. ➤ The TDURD setting is non-zero. Date Code 20110408 Instruction Manual...
  • Page 224 In response to the DNA command, the relay sends names of the Relay Word bits transmitted in the A5D1 message. The first name is associated with the MSB, the last name with the LSB. The DNA message for the SEL-551 is: <STX>"EN","INST","A","B","C","N","RS","LO","07A5"...

  • Page 225: Appendix E: Compressed Ascii Commands

    Appendix E Compressed ASCII Commands Overview The SEL-551 Relay provides Compressed ASCII versions of some relay ASCII commands. The Compressed ASCII commands allow an external device to obtain data from the relay, in a format which directly imports into spreadsheet or database programs, and which can be validated with a checksum.
  • Page 226 If a Compressed ASCII request is made for data that are not available, (e.g. the history buffer is empty or invalid event request), the relay responds with the following message: <STX>"No Data Available","0668"<CR><ETX> SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 227: Cascii Command-Sel-551

    Compressed ASCII Commands CASCII Command—SEL-551 CASCII Command—SEL-551 Display the SEL-551 Compressed ASCII configuration message by sending: CAS <CR> The SEL-551 sends: <STX> "CAS",5,"01A8"<CR> "CST",1,"01B7"<CR> "23H","MONTH","DAY","YEAR","HOUR","MIN","SEC","MSEC","IA","IB","IC", "IN","MOF","+5V_PS","+5V_REG"," 5V_REG","+10V_PS"," 10V_PS","VBAT", "TEMP","RAM","ROM","CR_RAM","EEPROM","2738"<CR> "1D","I","I","I","I","I","I","I","9S","9S","9S","9S","9S","9S","9S","9S","9S","9S", “9S","9S","9S","9S","9S","9S","15B4"<CR> "CHI",1,"01A1"<CR> "12H","REC_NUM","MONTH","DAY","YEAR","HOUR","MIN","SEC","MSEC", "EVENT","SHOT","CURR","TARGETS","1654"<CR> "20D","I","I","I","I","I","I","I","I","6S","I","I","22S","0A70"<CR> "CEV",1,"01AB"<CR> "7H","MONTH","DAY","YEAR","HOUR","MIN","SEC","MSEC","0BB9"<CR> "1D","I","I","I","I","I","I","I","05F4"<CR> "7H","IA","IB","IC","IN","IG","TRIG","RLY_BITS","0A85"<CR> "60D","F","F","F","F","F","1S","45S","06C8"<CR>...

  • Page 228: Chistory Command-Sel-551

    = L specifies long event report, as used in the EVE command = R specifies raw (unfiltered) analog data, as used in the EVE command The SEL-551 responds to the CEV command with the nth event report as shown below: <STX>"MONTH","DAY","YEAR","HOUR","MIN","SEC","MSEC","0ACA"<CR>...

  • Page 229: Appendix F: Setting Negative-Sequence Overcurrent Elements

    To avoid having negative-sequence instantaneous overcurrent elements trip for this transient condition, delay negative-sequence instantaneous overcurrent elements by at least 1.5 cycles (transient condition lasts less than 1.5 cycles). OGIC ® Use the SEL Variable timers described in Control Equation OGIC Variables/Timers on page 3.38.

  • Page 230: Coordinating Negative-Sequence Overcurrent Elements

    The coordination example is a generic example that can be used with any relay containing negative-sequence overcurrent elements that operate on 3I magnitude negative-sequence current. The SEL-551 can be inserted as the SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 231: Figure F.2 Distribution Feeder Protective Devices

    Setting Negative-Sequence Overcurrent Elements Coordinating Negative-Sequence Overcurrent Elements feeder relay in this example. Note that the overcurrent element labels in the example are not the same as the labels of the corresponding SEL-551 overcurrent elements. Coordination 1. Start with the furthest downstream negative-sequence overcurrent element (e.g., distribution feeder relay in a...

  • Page 232: Figure F.3 Traditional Phase Coordination

    (Guidelines 1 to 3) Applying negative-sequence overcurrent element coordination Guideline 1 to Guideline 3 results in the feeder relay “equivalent” phase overcurrent element (51EP) in Figure F.4. Curve for 51F is shown for comparison only. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 233: Figure F.4 Phase-To-Phase Fault Coordination

    F.5) by applying the equation given in guideline 4. The time dial (lever) and curve type of the element remain the same (if the element is a definite- time element, the time delay remains the same). Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 234: Figure F.5 Negative-Sequence Overcurrent Element Derived From "Equivalent" Phase

    It is coordinated with the distribution feeder phase or negative-sequence overcurrent elements and provides more sensitive and faster phase-to-phase fault backup. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 235: Other Negative-Sequence Overcurrent Element References

    This conference paper gives many good application examples for negative- sequence overcurrent elements. The focus is on the transmission system, where negative-sequence overcurrent elements provide better sensitivity than zero-sequence overcurrent elements in detecting some single-line-to-ground faults. Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 236 This page intentionally left blank...

  • Page 237: Appendix G: Modbus Rtu Communications Protocol

    Cyclical Redundancy Check (CRC) 2 bytes The SEL-551 SLAVEID setting defines the device address. Set this value to a unique number for each device on the Modbus network. For Modbus communication to operate properly, no two slave devices may have the same address.

  • Page 238: Table G.2 Sel-551 Modbus Function Codes

    Preset Single Register Read Exception Status Loopback Diagnostic Command Preset Multiple Registers Scattered Register Read Modbus Exception The SEL-551 sends an exception code under the conditions described in Table G.3. Responses Table G.3 SEL-551 Modbus Exception Codes Exception Error Type...

  • Page 239: Table G.4 01H Read Coil Status Commands

    Modbus RTU Communications Protocol Modbus RTU Communications Protocol SEL-551, the master device uses the data received. If there is not a match, the check fails and the message is ignored. The devices use a similar process when the master sends queries.

  • Page 240: Table G.5 02H Read Input Status Command

    Most masters use 4X references with this function code. If you are accustomed to 4X references with this function code, for 5 digit addressing, add 40001 to the standard database address. SEL-551 Relay Instruction Manual Date Code 20110408...

  • Page 241: Table G.6 03H Read Holding Register Command

    A successful response from the slave will have the following format: 1 byte Slave Address 1 byte Function Code (04h) 1 byte Number of Bytes of Data (n) n bytes Data 2 bytes CRC-16 Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 242: Table G.8 05H Force Single Coil Command

    Placeholder (00) 2 bytes CRC-16 The command response is identical to the command request. The coil numbers supported by the SEL-551 are listed in Table G.9. The physical coils (coils 1–5) are self resetting. Pulsing a set remote bit clears the remote bit.

  • Page 243: Table G.10 06H Preset Single Register Command

    Illegal Data Value (03h) Bad Packet Format 06h Preset Single The SEL-551 uses this function to allow a Modbus master to write directly to a database register. If you are accustomed to 4X references with this function Register Command code, for 6-digit addressing, add 400001 to the standard database addresses.

  • Page 244: Table G.12 08H Loopback Diagnostic Command

    Illegal Data Value (03h) Bad Packet Format 08h Loopback The SEL-551 uses this function to allow a Modbus master to perform a diagnostic test on the Modbus communications channel and relay. When the Diagnostic Command subfunction field is 0000h, the relay returns a replica of the received message.

  • Page 245: Table G.13 10H Preset Multiple Registers Command

    CRC-16 A successful response from the slave will have the following format: 1 byte Slave Address 1 byte Function Code (10h) 2 bytes Starting Address 2 bytes Number of Registers 2 bytes CRC-16 Date Code 20110408 Instruction Manual SEL-551 Relay...

  • Page 246: Table G.14 64H Scattered Register Read Command

    Illegal Data Value (03h) Illegal Write 64h Scattered The SEL-551 uses this function to allow a Modbus master to read noncontiguous registers in a single request. A maximum of 100 registers can Register Read be read in a single query.

  • Page 247: Table G.15 Sel-551 Modbus Command Region

    0000 0000 0000 1000 Communication Counters SEL-551 only. Switches the serial port protocol to SEL ASCII, the baud rate, parity, stop bits, and flow control remain the same. Parameter of Command code 11 is bit masked to allow you to manipulate several data regions simultaneously.
  • Page 248 Reading Event Data The Modbus Register Map (Table G.18) provides a feature that allows you to download complete event data via Modbus. The SEL-551 stores the 20 latest Using Modbus 15-cycle, full-length event reports. Please refer to Section 7: Standard Event Reports and SER for more detailed description.

  • Page 249: Table G.17 Assign Event Report Channel Using Address 00B2

    0000–0016 ASCII – – – – String 0017–0019 Revision ASCII – – – – String 001A–0022 Relay ID ASCII – – – – String 0023–002B Terminal ID ASCII – – – – String Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 250 +5 V power 0.01 supply voltage value 003B +5 V power – – – – – supply status message 0 = OK, 1 = Warn, 2 = Fail 003C +5_REG 0.01 power supply value SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 251 0 = OK, 2 = Fail 004A CR_RAM status – – – – – 0 = OK, 2 = Fail 004B EEPROM status – – – – – 0 = OK, 2 = Fail Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 252 Peak demand Amps 65535 residual current I 0061 Peak demand Amps 65535 negative-sequence current 3I Last Reset Time and Date—Peak Demand Metering 0062 Time 0063 0064 0065 Date 0066 0067 yyyy 1992 2999 SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 253 1 Bit 0 = 0 if any of bits 8–15 are set to 0 Bits 1–7 = 0 Bit 8 = LO Bit 9 = RS Bit 10 = Phase N 51/50 Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 254 Bit 11 = 51P1T Bit 12 = 51G1 Bit 13 = 51N1 Bit 14 = 51P2 Bit 15 = 51P1 0083 Row 2 Bit 0 = 1 if any of bits 8–15 are set to 1 SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 255 0 Bits 1–7 = 0 Bit 8 = CF Bit 9 = CC Bit 10 = OC Bit 11 = IN2 Bit 12 = IN1 Bit 13 = 50C Bit 14 = 50B Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 256 8–15 are set to 1 Bit 0 = 0 if all of bits 8–15 are set to 0 Bits 1–7 = 0 Bit 8 = SV8 Bit 9 = SV7 Bit 10 = SV6 SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 257 Bit 15 = 79RS 008B Row 10 Bit 0 = 1 if any of bits 8–15 are set to 1 Bit 0 = 0 if all of bits 8–15 are set to 0 Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 258 Bits 1–7 = 0 Bit 8 = OUT4 Bit 9 = OUT3 Bit 10 = OUT2 Bit 11 = OUT1 Bit 12 = Alarm Bit 13 = 0 Bit 14 = SV14T Bit 15 = SV13T SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 259 Event Time millisec 00A3 00A4 00A5 00A6 Event Date 00A7 00A8 yyyy 1992 2999 00A9 Event Type ASCII string 00AA see Note 3 00AB 00AC 00AD Shot 00AE Maximum phase 65535 current 00AF Targets Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 260 3 1/2 cycle –32767 32767 00C1 3 3/4 cycle –32767 32767 00C2 4 cycle –32767 32767 00C3 4 1/4 cycle –32767 32767 00C4 4 1/2 cycle –32767 32767 00C5 4 3/4 cycle –32767 32767 SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 261 13 1/2 cycle –32767 32767 00E9 13 3/4 cycle –32767 32767 00EA 14 cycle –32767 32767 00EB 14 1/4 cycle –32767 32767 00EC 14 1/2 cycle –32767 32767 00ED 14 3/4 cycle –32767 32767 Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 262 Event current Amps 65535 phase A 00FD Event current phase B Amps 65535 00FE Event current phase C Amps 65535 00FF Event neutral Amps 65535 current IN 0100 Event residual Amps 65535 current IG SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 263 NOTE 1: Reserved addresses return 8000h. NOTE 2: Registers (RW) are read-write registers. Registers (W) are write- only registers. All other registers are read-only. NOTE 3: Event Types Date Code 20110408 Instruction Manual SEL-551 Relay...
  • Page 264 Contact status is mapped in bit positions 7–15 in the register. The 0 bit position of this register is set equal to 1 if any of the 1–15 positions are set to 1. SEL-551 Relay Instruction Manual Date Code 20110408...
  • Page 265 SEL-551 Command Summary Access Level 0 The only thing that can be done at Access level 0 is to go to Access Level 1. The screen prompt is: = Command Enters Access Level 1. If the main board password jumper is not in place, the relay prompts for the entry of the Access Level 1 password in order to enter Access Level 1.
  • Page 266 Enter Access Level C. If the main board Access jumper is not in place, the relay prompts for the entry of the Access Level C password. Access Level C is reserved for SEL use only. Assert the CLOSE Relay Word bit. If CLOSE is assigned to an output contact (e.g., OUT2 = CLOSE), then the output contact will assert if command CLO is executed and the circuit breaker is open.
  • Page 267 SEL-551 Command Summary Access Level 0 The only thing that can be done at Access level 0 is to go to Access Level 1. The screen prompt is: = Command Enters Access Level 1. If the main board password jumper is not in place, the relay prompts for the entry of the Access Level 1 password in order to enter Access Level 1.
  • Page 268 Enter Access Level C. If the main board Access jumper is not in place, the relay prompts for the entry of the Access Level C password. Access Level C is reserved for SEL use only. Assert the CLOSE Relay Word bit. If CLOSE is assigned to an output contact (e.g., OUT2 = CLOSE), then the output contact will assert if command CLO is executed and the circuit breaker is open.

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