Monday

BATTERY SYSTEMS TRACK

Title: Battery Testing by the Standards and Field Experiences

2/27/17
9:30AM - 10:15AM
Presenter: Daniel Carreño-Perez and Volney Naranjo, Megger
Description:

Abstract - Batteries are the heart of electrical substations and telecommunications infrastructure; if DC power is lost, the substation is left unprotected and in the case of telecommunications, valuable data is jeopardized. However, despite existing regulations and standards, battery systems are not always maintained and tested as per their importance.

IEEE, NETA, and NERC provide guidelines on what, when, who, and how batteries should be tested. Publications from those entities contain information that is essential when developing a maintenance program and when performing a battery test in the field.

Maintenance and testing practices are defined by several factors, such as electrolyte, construction characteristics, and application; it is really important to take into account both the similarities and key differences for maintenance and test procedures between different battery types.

This paper will summarize and highlight the most important aspects of battery field testing in a simple and easy to follow document for three different type of batteries (VLA, VRLA and Vented NiCad). The reader will be provided with quick reference tables derived from IEEE and NETA recommendations along with a comparison to the current mandatory testing requirements from NERC.

In the end, the reader will be able to determine what should be included in a battery maintenance program, the schedule, types of tests required, and specific procedures. The authors will also discuss best practices and field recommendations, based on their experiences, for capacity and ohmic testing.

PROTECTIVE RELAYS TRACK

Title: Testing High Magnitude Faults on a Transmission Line Using COMTRADE Records: A Case Study

2/27/17
9:30AM - 10:15AM
Presenter: Mohit Sharma, Chinmay Desai, and Vijay Sundaram, Megger
Description:

Abstract - Modern testing techniques are reliable for testing most protective relays but some cases such as generator out-of-step and high magnitude line faults cannot be accurately tested with conventional methods. Another limitation of these methods is that the transient conditions that lead to CT saturation at the time of fault are ignored. The introduction of COMTRADE, a standard data format for data recording, has paved the way for users to test these special functions and cases. The complex protection schemes can also be validated by playing back an actual fault scenario.

This paper discusses the use of COMTRADE records to test an actual three phase fault that occurred on a 400 kV transmission line. The fault current magnitude was more than 30 times the nominal value. The modern testing practices recommend the use of multiple shots or pulse ramping to carry out relay testing. However, this does not take into account the whole power system’s condition at the time of the fault. As a result, the accuracy is compromised. With higher magnitudes of fault current, the error is quite significant. This paper provides a solution for testing such high amplitude fault scenarios using a practical case study. In addition, this paper describes in detail the advantages of using COMTRADE based testing over other conventional methods.

POWER TRANSFORMERS TRACK

Title: Why Get Excited about Excitation Current Tests

2/27/17
9:30AM - 10:15AM
Presenter: Keith Hill, Doble Engineering Company
Description:

Abstract - This paper will review the importance of performing excitation current tests as a routine test when performing power factor tests on a transformer. The different test procedures for various windings will be covered. A case study will be reviewed in which excitation current tests indicated a problem while other tests such as power factor, low voltage TTR and winding resistance did not indicate a problem.

ELECTRICAL SAFETY TRACK

Title: Improving Human Performance

2/27/17
9:30AM - 10:15AM
Presenter: D. Ray Crow, DRC Consulting Ltd.
Description:

Abstract - Electrical safety incidents and injuries can be the result of inappropriate work behavior or what is referred to as “unsafe acts.” This occurs even though training and education have been provided on the electrical hazards and the possible consequences. Providing training to people is not enough to motivate them to follow the procedures. When unsupervised, those people who are aware of the hazards may still believe they are qualified to take risks because previous “unsafe acts” have not resulted in an incident. This presentation will provide information on what motivates people to intrinsically follow proper electrical safe procedures. By understanding these principles, human performance can be positively changed and the electrical work practices of personnel can be improved to consistently follow safe work procedures.

EQUIPMENT & RELIABILITY TRACK

Title: How Vacuum Interrupters Work and How They Fail

2/27/17
9:30AM - 10:15AM
Presenter: Finley Ledbetter, Group CBS, Inc.
Description:

Abstract - Since their introduction into the power interruption market in the 1970’s, vacuum interrupters have become smaller while the range of current and voltage ratings they cover has expanded as materials and designs have improved. Despite all of the design changes, the same basic designs and principles govern the functioning of these devices.

Vacuum interrupters have long been recognized for their reliability; a quality designed and manufactured vacuum interrupter will usually last decades if operated and maintained within the parameters designated by the manufacturer. However, vacuum interrupters sometimes fail by: loss of vacuum, envelope insulation failure, or premature contact wear out. This paper will describe the basic designs and principles of how vacuum interrupters work, improvements that have been made over time, as well as conditions which can bring about failures.

EQUIPMENT & RELIABILITY TRACK

Title: Commissioning of Plant Electrical System Using Distributed Testing

2/27/17
10:30AM - 11:15AM
Presenter: Randall Sagan, MBUSI Mose Ramieh III, PGTI, a CE Power Company & Will Knapek, OMICRON electronics Corp. USA
Description:

Abstract - This paper discusses in detail the commissioning of a communication-assisted protection and control scheme for a plant expansion project. The project included new systems utilizing functionality that could not be tested with conventional element testing techniques. Component function and application testing is the most widely accepted method for testing traditional protection schemes. This ensures that the protection system and each of its components will operate as designed under all system conditions. However, the complex protection schemes utilizing multifunctional devices and communication networks used in this project required “distributed testing” techniques for commissioning. The communication-assisted protection and control schemes tested during this process were:

- Line differential protection
- Arc-flash detection and tripping
- Fast-bus tripping protection
- Breaker failure backup protection
- IED failure backup protection

This paper defines the concepts of the communication-assisted protection and control scheme and the testing techniques used during the commissioning process. System configuration and test equipment requirements along with the monitoring and reporting of the tests performed are discussed. Solutions for testing the individual devices as well as for the distributed applications are described in detail.

BATTERY SYSTEMS TRACK

Title: Station Battery Maintenance 101: What You Need to Know

2/27/17
10:30AM - 11:15AM
Presenter: Tom Sandri, Shermco Industries
Description:

Abstract - There are various philosophies and opinions for maintaining and testing battery systems. These approaches can range from the “Do nothing and replace when the battery fails” to the “Intense time-based battery maintenance regiment.” Obviously the “Do nothing” approach appears a little flawed. Keep in mind that a battery is a perishable item with a shelf life. Since batteries are perishable items, there are several things necessary for them to perform to expectations. Besides being perishable, another unique feature of a battery that is unlike other electrical assets is that a battery uses chemicals, metal alloys, plastics, welds, and bonds that must interact with each other to produce a constant DC source. For this reason the type of battery should be considered before embarking on a battery maintenance program. There are a number of recommended practices for battery testing. This paper will explore accepted maintenance practices and provide the foundation to implement a winning battery maintenance program.

POWER TRANSFORMERS TRACK

Title: Understanding the Value of Electrical Testing for Power Transformers

2/27/17
10:30AM - 11:15AM
Presenter: Charles Sweetser, OMICRON electronics Corp. USA
Description:

Abstract - The electric power industry is always looking for the best approach to better determine and continually identify the condition of power transformers. It is important to understand the need and value for comprehensive testing of power transformers.

The comprehensive suite of basic or standard electrical field tests widely applied today in transformer diagnostics, though careful selection, hierarchal value, and appropriate times of use, includes:

 

  • Power Factor
  • Exciting Current
  • Turns/Voltage Ratio
  • Leakage Reactance
  • DC Winding Resistance
  • Sweep Frequency Response Analysis (SFRA)

These specific diagnostic tests have been selected as the primary focus for this presentation and discussion.

This paper focuses on how diagnostic techniques can be applied to power transformers as part of the standard condition assessment protocol. The audience will be provided with an understanding, application, and analysis of these tests, supported by specially selected case studies validating the value that these diagnostic tests bring to testing, and finally assessing, power transformers.

ELECTRICAL SAFETY TRACK

Title: Electrical Safety for Contractors (Multi-Employer) Working in Industrial Facilities

2/27/17
10:30AM - 11:15AM
Presenter: Dennis Neitzel, AVO Training Institute, Inc.
Description:

Abstract - Contractors who work on industrial facilities must understand the electrical hazards associate with the work they are performing, along with the requirements of OSHA CPL 2-0.124 Multi-Employer Citation Policy, as well as the specific multi-employer requirements of OSHA 29 CFR 1910 regulations, and NFPA 70E Standard for Electrical Safety in the Workplace for working on a multi-employer worksite. They must also have knowledge of the electrical safety requirements, procedures, and responsibilities that pertain to their respective job assignments. The OSHA “Information Transfer” and the NFPA 70E “Host and Contract Employer’s Responsibilities” requirements between the contractor and the host employer will be discussed. Additional multi-employer issues will be address that pertain to OSHA 1910.147 “The Control of Hazardous Energy (lockout/tagout)” section titled “Outside Personnel (Contractors, etc.)”, as well as the requirements of OSHA 1910.146 “Permit-Required Confined Spaces for General Industry” Section (c)(8) that identifies the requirements for the host employer working with contractors. Also addressed are the requirements for safe work practices, which include the safe approach and working distances to overhead power lines when operating cranes and other boom type equipment or when handling conductive objects, where contact might be made. This section applies to electrical workers as well as non-electrical workers such as crane or equipment operators, riggers, material handlers, and other ground personnel who might be at risk.

POWER TRANSFORMERS TRACK

Title: Sweep Frequency Response Analysis (SFRA) and the Best Practices for Reliable Results

2/27/17
11:30AM - 12:15PM
Presenter: Sanket Bolar and Robert Foster, Megger
Description:

Abstract - Sweep Frequency Response Analysis (SFRA) has become increasingly popular in recent years as a means for evaluating the overall condition of a transformer. Through a series of low voltage, multi-frequency sweeps, it is possible to analyze various components in a transformer such as the core, windings, tap leads and connections. Sweep Frequency Response Analysis is a very sensitive test and the results can be easily influenced by numerous factors - internal and external. Hence, in order to obtain accurate test results, it is necessary to eliminate or at least minimize the external factors that influence these results.

This paper will discuss different scenarios that can cause shifts in resonant frequencies and amplitudes leading to possible misinterpretation of the test results. It will focus on the measures that can be adopted by the technician to ensure accurate measurements. Real word examples will be analyzed to highlight the influences of tap changer position, core magnetization and various other factors that can affect the measurement causing unwanted deviations in the results.

In the end the reader will have a better understanding of SFRA testing and will be able to conduct the test more efficiently and accurately.

ELECTRICAL SAFETY TRACK

Title: Guarded or Unguarded and Why It Makes a Safety Difference

2/27/17
11:30AM - 12:15PM
Presenter: Jim White, Shermco Industries
Description:

Abstract - Many people are vague on the concept of whether equipment is safe to work on, often mistaking a low-risk task as one that is high-risk. This paper looks at how guarded and unguarded equipment comes into play in assessing risk and how it should be handled in the field.

EQUIPMENT & RELIABILITY TRACK

Title: Primary Current Injection Testing: Then and Now

2/27/17
11:30AM - 12:15PM
Presenter: Robert Probst, Megger
Description:

Abstract - Primary Current Injection is a routine test performed on Circuit Breakers in low voltage installations. It is the only test technique able to verify with certainty both the condition and the proper functionality of a low voltage circuit breaker and its components. Depending on the type of trip unit, a typical primary test sequence can consist of up to four individual high current tests to check various points of the circuit breaker’s time-current-curve; a) a long-time test, b) an instantaneous test, c) a short-time delay test, and d) a ground fault test.

Performing a primary current injection test is often very time intensive, and because most primary test instruments still follow a traditional design, testing usually requires skilled personnel who understand the tests to be carried out, the object under test, as well as know how to operate the test instrument. Common problems in the field include: selecting appropriate trip settings, availability of time-current-curves, identifying the correct curve, test objects being heated up due to frequent output current adjustments, waiting periods before proceeding to the next circuit breaker pole, and interpreting the test results. Comparing measurements to actual pass/fail limits, and creating a test report afterwards are the most time-consuming tasks.

This paper demonstrates how low voltage circuit breaker testing can be carried out as a fast and automated process using sophisticated solid state technology and a user-interactive interface to address the above listed issues. The paper then provides recommendations to other challenges such as the availability of input power and its effect on desired output current, size and weight of the test instrument when working in confined spaces, and how to test high impedance test objects. Additionally, it will highlight the value of computer-aided comparisons between actual measurements and digitized curves to analyze and evaluate the test results.

PROTECTIVE RELAYS TRACK

Title: Influence of Non-Linear Loads on Generator Differential Protection

2/27/17
11:30AM - 12:15PM
Presenter: Vijay Sundaramand Dhanabal Mani, Megger
Description:

Abstract - The primary function of generator differential protection scheme is to protect the generator from any internal faults. Any time delay in isolating the faulty circuit could result in permanent damage to the generators. A typical generator differential protection scheme (87G) does not consider the harmonic content of the system. Due to the proliferation of non-linear loads, the effect of harmonic content has to be considered when designing a differential protection scheme. The increase in harmonic content can lead to unwanted operation of the differential protection.

State-of-the-art protection relays are capable of monitoring the waveforms and isolate the circuit in the event of high harmonic content. This paper focuses on the effects of connecting heavy non-linear loads to the power system located near generators. The susceptibility of generator differential protection scheme to external load condition is explained using a practical case-study.

The case-study involves a rectifier transformer in a zinc plant located in South Asia. Due to multiple operations of 87G in the nearby generating stations, an investigation was carried out. The investigation led to the determination that the harmonic distortion in the waveform caused asymmetric CT saturation in the 87G circuit. This paper discusses the factors affecting a differential protection scheme. Also, the paper will thoroughly explain the root cause of unwanted relay operation using real life case-study.

BATTERY SYSTEMS TRACK

Title: NERC Requirements for Battery Acceptance and Maintenance Testing

2/27/17
11:30AM - 12:15PM
Presenter: Steve Canale, American Electrical Testing Co., Inc.
Description:

Abstract - DC Systems are a critical component of electric utility substations and generation plants. Failure of any component within the DC System during a power disturbance can result in loss of power to utility customers, substation equipment damage, and possible injury to on-site personnel. These DC systems must be tested, maintained, and inspected at defined intervals to help assure that they will be available to provide power in the event of a station service disturbance.

The North American Electric Reliability Corporation (NERC) has published specific ‘minimum’ requirements regarding testing, maintenance, inspection, and associated documentation of substation batteries. These requirements are detailed in NERC PRC-005.

In this paper we will discuss the importance of maintaining reliable substation DC systems. We will also outline the requirements that NERC has imposed and how these requirements differ from the IEEE, NFPA, and NETA standards that are typically referenced. Finally, we will discuss the requirements for properly documenting the test, maintenance, and inspection results.

PowerDB Users Group Meeting

Title: PowerDB Users Group

2/27/17
12:15PM - 2:15PM
Description:

Annual User’s Group Meeting open to licensed users of PowerDB Pro Software. Agenda will include presentations by the PowerDB Pro development team as well as utility, industrial, and contractor groups discussing how this product is an integral part of their business operations. Pre-registration is required by contacting PowerDB at (979) 690-7925 ext. 702 or by registering at www.powerdb.com.

SYMPOSIUM

Symposium: Medium-Voltage Vacuum Circuit Breakers: An Industry Update

2/27/17
2:15PM - 5:00PM
Description:

Presenters:
David Huffman, Power Systems Testing Co.
Tim Reed, Vertiv – Electrical Reliability Services
Finley Ledbetter, Group CBS, Inc.
Dan Hook, Western Electrical Services, Inc.

Abstract - Medium-voltage circuit breakers are key and integral to system reliability and electrical power system performance, and have been a part of the electrical landscape for many years. This symposium will focus on the medium-voltage circuit breaker technology, both new and old, and will provide insight and updates from medium-voltage circuit breaker subject matter experts. Gain knowledge and learn about trends in the industry from true experts in the field. Sure to be an informative and insightful presentation, and one that should not be missed!

POWER TRANSFORMERS TRACK

Title: Emergency Transformer Bushing Replacement

2/27/17
2:15PM - 3:00PM
Presenter: Mark Haas, Power Asset Recovery Corporation and Randy Williams, ABB
Description:

Abstract - In the electrical testing business there is often the dilemma of testing the customers’ transformer and discovering a bushing that has a poor power factor. The customer is looking to the test company for quick solutions to maintain and re-energize the transformer. Finding the Companies with the experience in providing quick replacement bushings can be a challenge. If a direct replacement bushing is not readily available there are other solutions to the problem. Dimensional issues can often be overcome with the utilization of a custom fabricated adaptor flange to match a readily available bushing of the same voltage and current characteristics to the application upon the transformer experiencing a problematic bushing.

The paper ABB and Power Asset Recovery Corporation would propose, covers specific situations and applications of power transformer bushing replacements. Power Asset Recovery Corporation maintains a stock of readily available power transformer bushings from 5,000 volts thru 500,000 volts. Each bushing replacement can be very unique as we would discuss in the paper. Attention to detail is critical including all dimensional data, flange adaptation, gasket locations and styles, CT pocket location, corona shielding on high BIL bushings, and internal connections to the existing lead configuration from the transformer core and coil assembly.

Our Companies offer the combined experience of transformer design engineers should the changes require a clearances and application review. Unique problems call for unique solutions. Many times the option of waiting 12 to as much as 20 weeks or more for a duplicate bushing is not the solution the customer is willing to accept. ABB is recognized as the worldwide leader in the design, manufacture, and application of power transformer bushings.

ELECTRICAL SAFETY TRACK

Title: Application of Work Flow Processes in an Electrical Safety Program

2/27/17
2:15PM - 3:00PM
Presenter: Terry Becker, ESPS Electrical Safety Program Solutions INC.
Description:

Abstract - Energized electrical work tasks are executed following a “Work Flow Process.” A company’s Electrical Safety Program can use this process and a related flow chart to illustrate the steps required to be taken by a Qualified Person to ensure process and documentation requirements are fulfilled before energized electrical work is executed. An example “Work Flow Process” flow chart will be provided and the steps it outlines reviewed as applied from an employer’s Electrical Safety Program and overall Occupational Health & Safety Management System.

EQUIPMENT & RELIABILITY TRACK

Title: How to Choose the Right Power Monitoring Tools

2/27/17
2:15PM - 3:00PM
Presenter: Ross Ignall, Dranetz Technologies
Description:

Abstract - So, you need to measure the power - all you have to do is find a power monitor, hook it up and you’re done, right? Wrong - that’s a common mistake that could cost you a lot of time and money! Power monitoring can range from simple V & I measurements, to power & energy consumption, to complex power quality surveys and anything in between. The actual application will dictate the appropriate monitoring tools required, transducers, duration and techniques used. A little bit of guidance will go a long way towards getting it done right the first time!

This interactive session will compare and contrast the various types of power monitoring applications, what they have in common, and more importantly, the differences between them that make their requirements unique. We’ll discuss the appropriate monitoring tools for each major application, standards, and some tips to get you started on the right path. We’ll also touch on the latest technologies available in the power monitoring industry.

PROTECTIVE RELAYS TRACK

Title: Understanding Basic High Speed Tripping and Communications (Basics of Tone and Carrier Schemes)

2/27/17
2:15PM - 3:00PM
Presenter: Jay Garnett, Doble Engineering Company
Description:

Abstract - One of the most important functions of protecting a bulk transmission line is the high speed tripping of that line in the event of a fault. In order to cause the least amount of disruption to the power gird, the fault must be identified and trip the line off as fast as possible. This is to minimize the effect to other lines as well as power generation supplying those lines.

High speed communication is used to send signals to the other end of the line at a remote station to either trip the breaker at the other end or to stop it from tripping. Communication signals are transmitted over several ways to allow the relays at both ends of the line to evaluation what is happening during the fault and trip the breaker accordingly.

This paper will cover the basics of phase and ground zone protection as well as other protection and how it interfaces with the high speed communication equipment. It will also go over the basics or how those communication devices send the signals to the other end of the transmission line.

PROTECTIVE RELAYS TRACK

Title: End-To-End Testing Methods Compared

2/27/17
3:15PM - 4:00PM
Presenter: Christopher Pritchard and Will Knapek, OMICRON electronics Corp. USA
Description:

Abstract - For many years now we see the increasing number of communication assisted protection schemes. While it is mandatory to test these protection schemes for compliance, the NERC misoperation study 2013 also underlined the importance of testing not only for relay failures but also for communication failures and design errors.

End-to-end or distributed testing is already a well-accepted method for line protection testing. The same technique for testing line protection can also be applied for bus protection or distribution schemes. While most technicians are implementing a certain method of distributed testing, there are many different methods available that can save a significant amount of time. Opposed to other papers on this topic, this paper tries to give a broad overview of the different methods of conducting a distributed test, which will provide technicians with a guide to choose the right tool for their next job. Each method will be characterized by the way the test inputs are defined, the test cases are executed and the results are assessed. Additionally we will give tips for each method, what to consider when preparing a distributed test, how systematical order of tests can reduce error and how to troubleshoot failing tests in the field.

An in depth discussion will be dedicated on testing distributed logic. Additionally to the complexity of running a setup with multiple test sets, this use case adds special requirements. Test cases for logic usually involve a sequence of system events. Each event causes the real power system to transition into another state. Logic schemes expect and rely on this transition to work properly. A simple example is a reclosing logic that shall be tested; if the 52a status and current do not disappear, the relay will fall back to its breaker failure logic. The conclusion is that all test sets have to output a consistent system state for each test case. The paper will show a method that has been applied several times successfully in the field to test distributed logic.

POWER TRANSFORMERS TRACK

Title: A Systematic Approach to Analyzing Exciting Current Measurements on Power Transformers

2/27/17
3:15PM - 4:00PM
Presenter: Brandon Dupuis, OMICRON electronics Corp. USA
Description:

Abstract - The exciting current field test has long been accepted as a powerful tool for identifying power transformer faults, such as insulation failures, tap-changer defects, and core defects. The exciting current measurement produces unique test results, which differ based on the transformer core, winding configuration, and tap-changer design, and are often not fully understood.

A systematic approach will be presented for analyzing transformer exciting current measurements, which will help the audience identify incipient failure modes within power transformers. Failure modes associated with the main core, winding assembly, regulating winding, and preventative autotransformer will be discussed.

Case studies will be presented directly focusing on the importance of the high-voltage exciting current measurement, and in general, a thorough electrical diagnostic testing action plan.

ELECTRICAL SAFETY TRACK

Title: Human Performance Best Practices in Electrical Safety

2/27/17
3:15PM - 4:00PM
Presenter: Mike Doherty, eHazard
Description:

Abstract - The concept of human performance in electrical safety and how that can be applied in a practical sense in everyday job planning will be discussed. Studies by high risk industries indicate that human error is often the root cause of incidents. This is certainly true in the electrical sector in many cases. Asking why five or six times in regards to the true root cause of any electrical incident is an outstanding way to determine the corrective action plans that need to be implemented to ensure that it never happens again. Annex U, Human Performance and Workplace Electrical Safety, from CSA Z462 - 2015 (Workplace Electrical Safety) will be heavily referenced during this presentation. This Annex was sent as a Public Input (PI) to the NFPA 70E - 2018 process and as such is expected to be a very good candidate for inclusion to that edition.

EQUIPMENT & RELIABILITY TRACK

Title: Making Reliability Lean & Mean

2/27/17
3:15PM - 4:00PM
Presenter: David McGuire
Description:

Abstract - If times get tough…the tough get going. If the recent decade has not presented you or your company with some tough economic times, then you are blessed and highly favored. For the rest of us faced with maintaining a high reliability standard to ensure a competitive bottom line for our company the following information should be helpful in getting the most out of your electric maintenance budget.

PRESENTATION OUTLINE:

  • Electric motor fundamentals
  • The trifecta of electric motor maintenance
  • Fault Zone Analysis of electric motors
  • Reliability after the retirement boom
  • Monitor motors, focus on faults
ELECTRICAL SAFETY TRACK

Title: Design, Implementation, and Testing of Arc-Flash Mitigation on Low and Medium-Voltage Systems

2/27/17
4:15PM - 5:00PM
Presenter: Christopher Inshaw, Southwest Energy Systems, LLC
Description:

Abstract - Many times the results of Arc-Flash risk assessments determine locations where the calculated incident energies exceed the available personal protective equipment (PPE) or site specific maximum safe working level. In order to safely perform energized work at these locations, mitigation must be put in place to reduce the incident energies to a level where personnel can be protected with the available PPE. Most forms of mitigation use various means to reduce the arcing time, which it typically the only variable that can be changed in a system. This paper will describe some of the options for mitigating incident energies at low and medium voltage equipment from the initial design and analysis, through safe installation, and finally field testing to verify that the mitigation operates correctly per the design.

EQUIPMENT & RELIABILITY TRACK

Title: Grounding Fundamentals That Help Avoid Electrical Disasters

2/27/17
4:15PM - 5:00PM
Presenter: David Brender, Copper Development Association
Description:

Abstract - Data centers, 9-1-1 and broadcast facilities and other sensitive facilities have both unique and universal powering, grounding and bonding requirements, often overlooked, and not understood by most designers and contactors. The primary focus of this presentation is to recommend wiring and grounding techniques and practices that should be part of the design of new or renovated structures, and to examine in particular several case studies of actual data center some of the topics we will discuss include: the cause of power quality problems and cost-effective solutions; the limitations of the National Electrical Code grounding; what’s required and what’s desired; ground resistance, ground loops; general wiring practice, separating sensitive loads; surge suppression; grounding systems; and other topics.

PROTECTIVE RELAYS TRACK

Title: Man-Made Faults – Line Protection Operation for an Unintended Phase Cross-Connect Condition

2/27/17
4:15PM - 5:00PM
Presenter: Ryan McDaniel and Jon Larson, Schweitzer Engineering Laboratories, Inc.
Description:

Abstract - For a temporary operating condition, a utility installed a new switch to tie together two subtransmission lines. During the installation, operating personnel inadvertently crossed two phases. When the operators closed the line switch, it created an unusual fault, cross-connecting two phases between the sources and causing the line protection to operate on one end of the line. Another relay protecting a line connected to a common bus also tripped for this condition. The elements that operated in these microprocessor-based relays were compensator phase distance elements. Compensator phase distance relays have evolved from the electromechanical relays of the 1950s to protection elements included in today’s microprocessor-based relays. In this paper, we discuss the theory of operation of compensator phase distance relays and some of their applications. We then explain why the compensator phase distance elements operated for this phase cross-connect condition by analyzing the event reports from the relays involved. We use symmetrical components to demonstrate how to analyze the phase cross-connect condition and analyze the responses to this condition by a negative-sequence voltage-polarized directional element and a positive-sequence polarized mho element. Finally, we discuss methods for making a compensator phase distance element secure for similar phase cross-connect conditions.

POWER TRANSFORMERS TRACK

Title: Cable Fault Location Techniques when Faced with Corroded Neutrals

2/27/17
4:15PM - 5:00PM
Presenter: Robert Probst and Jason Souchak, Megger
Description:

Abstract - While the share of installed cables without a jacket generally continues to decrease, the cables that remain continue to age. As they age, it is increasingly likely that a fault will develop on these cables, namely pinhole faults. It is particularly troublesome to locate faults on unjacketed cables. Regular Time Domain Reflectometry (TDR) based fault location techniques often do not work, due to the corrosion of the neutral wires. While there is no guaranteed action that would result in locating the fault, this paper outlines some advanced methods – based on field experience – that can help when locating faults on these kinds of cables.

This paper will discuss the Impulse Current method, which does not rely on the neutral wires being intact, but instead measures a standing wave of current that oscillates between the fault locating equipment and the actual fault location. It then also addresses a different TDR based method of reducing the distance of cable that the radar is unable to interpret, and therefore minimizes the amount of cable test personnel must walk alongside while thumping through a process of elimination. The reader will be presented with a comparison and some recommendations on what method would be the best to choose depending on the fault situation. The shown techniques provide additional approaches for test personnel to quickly and safely locate the fault when regular arc reflection technology cannot.