Timing Test Procedures

The timing test procedure for directional overcurrent elements is identical to the procedure described in the earlier “Time Overcurrent (51) Protection Testing” or “Instantaneous Overcurrent (50) Protection Testing” chapters of this publication once the correct direction has been applied. Please review those chapters for detailed timing test procedures and ensure that the correct direction is applied for tests.

6. Tips and Tricks to Overcome Common Obstacles

The following tips or tricks may help you overcome the most common obstacles.

¾ Apply pre-fault currents and voltages and perform a metering test.

¾ All of the examples have been applied for ABC or counter-clockwise rotation with 90º in the upper quadrants and -90º in the lower quadrants or the phasor diagram. Adjust the angles accordingly if you use different rotation or references.

¾ Different relay manufacturers have different phasor references. Make sure you understand the manufacturer’s phasor references. For example, GE relay phasors use a lagging reference; SEL relays use a leading reference. 30º displayed on a GE relay is -30º on an SEL relay.

¾ Some relays use sequence components to determine direction. Applying a P-N fault will create positive, negative, and zero sequence components. It is the best option for simple directional testing. If the element does not operate, try lowering the fault voltage for the corresponding high current to create a larger reference signal.

¾ Make sure the current under test is greater than the pickup and is not at unity power factor.

¾ SEL relays that have manual directional settings can use impedance blinders that may prevent normal directional operation. Ask the design engineer to provide specific test parameters.

¾ Is the direction element turned on?

¾ Is the directional element applied to the overcurrent element?

Bibliography

Tang, Kenneth, Dynamic State & Other Advanced Testing Methods for Protection Relays Address Changing Industry Needs

Manta Test Systems Inc, www.mantatest.com

Tang, Kenneth, A True Understanding of R-X Diagrams and Impedance Relay Characteristics Manta Test Systems Inc, www.mantatest.com

Blackburn, J. Lewis, (October 17, 1997) Protective Relaying: Principles and Application New York. Marcel Dekker, Inc.

Elmore, Walter A., (September 9, 2003) Protective Relaying: Theory and Applications, Second Edition

New York. Marcel Dekker, Inc.

Elmore, Walter A., (Editor) (1994) Protective Relaying Theory and Applications (Red Book) ABB

GEC Alstom (Reprint March 1995) Protective Relays Application Guide (Blue Book), Third Edition GEC Alstom T&D

Schweitzer Engineering Laboratories (20011003) SEL-300G Multifunction Generator Relay Overcurrent Relay Instruction Manual

Pullman, WA, www.selinc.com

Schweitzer Engineering Laboratories (20010625) SEL-311C Protection and Automation System Instruction Manual

Pullman, WA, www.selinc.com

Schweitzer Engineering Laboratories (20010808) SEL-351A Distribution Protection System, Directional Overcurrent Relay, Reclosing relay, Fault Locator, Integration Element Standard Instruction Manual

Pullman, WA, www.selinc.com

Costello, David and Gregory, Jeff (AG2000-01) Application Guide Volume IV Determining the Correct TRCON Setting in the SEL-587 Relay When Applied to Delta-Wye Power Transformers Pullman, WA, Schweitzer Engineering Laboratories, www.selinc.com

Schweitzer Engineering Laboratories (20010606) SEL-587-0, -1 Current Differential Relay Overcurrent Relay Instruction Manual

Pullman, WA, www.selinc.com

Schweitzer Engineering Laboratories (20010910) SEL-387-0, -5, -6 Current Differential Relay Overcurrent Relay Data Recorder Instruction Manual

Pullman, WA, www.selinc.com

GE Power Management (1601-0071-E7) 489 Generator Management Relay Instruction Manual Markham, Ontario, Canada, www.geindustrial.com

Bibliography (Cont.)

GE Power Management (1601-0044-AM (GEK-106293B)) 750/760 Feeder Management Relay Instruction Manual

Markham, Ontario, Canada, www.geindustrial.com

GE Power Management (1601-0070-B1 (GEK-106292)) 745 Transformer Management Relay Instruction Manual

Markham, Ontario, Canada, www.geindustrial.com

GE Power Management (1601-0110-P2 (GEK-113321A)) G60 Generator Management Relay: UR Series Instruction Manual

Markham, Ontario, Canada, www.geindustrial.com

GE Power Management (1601-0089-P2 (GEK-113317A)) D60 Line Distance Relay: Instruction Manual

Markham, Ontario, Canada, www.geindustrial.com

GE Power Management (1601-0090-N3 (GEK-113280B)) T60 Transformer Management Relay: UR Series Instruction Manual

Markham, Ontario, Canada, www.geindustrial.com

Beckwith Electric Co. Inc. M-3420 Generator Protection Instruction Book Largo, FL, www.beckwithelectric.com

Beckwith Electric Co. Inc. M-3425 Generator Protection Instruction Book Largo, FL, www.beckwithelectric.com

Beckwith Electric Co. Inc. M-3310 Transformer Protection Relay Instruction Book Largo, FL, www.beckwithelectric.com

Young, Mike and Closson, James, Commissioning Numerical Relays Basler Electric Company, www.baslerelectric.com

Basler Electric Company (ECNE 10/92) Generator Protection Using Multifunction Digital Relays www.baslerelectric.com

I.E.E.E., (C37.102-1995) IEEE Guide for AC Generator Protection

Avo International (Bulletin-1 FMS 7/99) Type FMS Semiflush-Mounted Test Switches Cutler-Hammer Products (Application Data 36-693) Type CLS High Voltage Power Fuses

Pittsburg, Pennsylvania

GE Power Management, PK-2 Test Blocks and Plugs

Index

50 - Instantaneous Overcurrent Protection ... 1–13 Breaker Failure (50BF)... 3 Directional Ground Overcurrent... 31–45 IAC Inverse Curves ... 16 IEC Inverse Curves... 16 Instantaneous Overcurrent Protection... 1–13 Maximum Torque Angle (MTA)

Directional Overcurrent (67) ... 42–43 Pickup Testing

Directional Overcurrent ... 38–45 Instantaneous Overcurrent Element... 4–5 Time Overcurrent ... 19–23

Residual Neutral Overcurrent Protectio

Instantaneous Overcurrent (50) ...12 Residual Neutral Overcurrent Protection

Time Overcurrent (51) ...29 Time Overcurrent Protection...15–30 Pickup Settings...17 Time Dial Settings...17 Time Testing

Directional Overcurrent...45 Instantaneous Overcurrent (50) ...10–11 Time Overcurrent (51) ...24–29

About The Relay Testing Handbook…

The Relay Testing Handbook was created for relay technicians from all backgrounds and provides the knowledge necessary to test most of the modern protective relays installed over a wide variety of industries. Basic electrical fundamentals, detailed descriptions of protective elements, and generic test plans are combined with examples from real life applications to increase your confidence in any relay testing situation. A wide variety of relay manufacturers and models are used in the examples to help you realize that once you conquer the sometimes confusing and frustrating man-machine interfaces created by the different manufacturers, all digital relays use the same basic fundamentals and most relays can be tested by applying these fundamentals.

This package provides a step-by-step procedure for testing the most common overcurrent protection applications: Instantaneous Overcurrent (50), Time Overcurrent (51), and Directional Overcurrent (67). Each chapter follows a logical progression to help understand why overcurrent protection is used and how it is applied. Testing procedures are described in detail to ensure that the protective elements have been correctly applied. Each chapter uses the following outline to best describe the element and the test procedures.

1. Application 2. Settings

3. Pickup Testing 4. Timing Tests

5. Tips and Tricks to Overcome Common Obstacles

Real world examples are used to describe each test with detailed instructions to determine what test parameters to use and how to determine if the results are acceptable.

About The Author…

Chris Werstiuk is a graduate of the Electrical Engineering Technology program from the Northern Alberta Institute of Technology (NAIT), a Journeyman Power System Electrician, and a Professional Engineer in the state of Nevada. Werstiuk has been involved with relay testing for over a decade across the Americas in environments ranging from nuclear power plants to commercial buildings and nearly everything in between. He has authored several articles in NETA World and presented several papers at the annual International Electrical Testing Association (NETA) conferences.

Werstiuk is also the founder of www.RelayTesting.net, an online resource for testing technicians

who need custom test leads, test sheets templates, step-by-step testing guides, or an online forum to

exchange ideas and information.