I-Gard Corporation I-GARD CORPORATION PARTNER IN GROUND FAULT PROTECTION August 2014 Potential ground faults often go unnoticed and can cause havoc on plant production processes. Shutting down power and equipment, ground faults disrupt the flow of products through manufacturing processes, leading to hours or even days of lost productivity. Undetected ground faults can also pose potential health and safety risks to personnel. Ground faults can lead to safety hazards such as equipment malfunctions, fire and electric shock. Ground faults can cause serious damage to equipment and to your processes. During a fault condition, equipment can be damaged and processes shut down, seriously affecting your bottom line. I-Gard is acknowledged as the leader in the field of ground fault protection. I-Gard’s longstanding relationships with a variety of Original Equipment Manufacturers (OEM) including ABB, Eaton Yale, General Electric, Group Schneider and Siemens, attest to our exceptional level of quality and performance. the best technology The concern for ground fault protection is based on four factors: 1 The majority of electrical faults include ground. 2 The ground fault protective sensitivity can be relatively independent of continuous load current values and thereby have lower pickup settings than phase protective devices. 3 Since ground fault currents are not transferred through system power transformers… the ground fault protection for each system voltage level is independent… This permits faster relaying that can be afforded by phase protective devices. 4 Arcing ground faults that are not properly detected and cleared can be extremely destructive. Over the last 30 years, I-Gard Corporation, formerly known as IPC Resistors Inc., has grown from a resistor only company to one that fully incorporates our ground fault protection line into the company. We work to achieve our business objectives responsibly and respond to our customer’s needs and concerns. From research and development to the manufacturing and distribution of our products, safety and quality are our first considerations. We are committed to manufacturing quality products and demand equivalent standards from our suppliers to help ensure customer safety. Quality Systems: I-Gard’s policies, guidelines, core requirements and procedures, are designed to ensure consistent product quality worldwide. We are constantly evaluating our systems in order to maintain the highest product quality. Education and Training: I-Gard provides ongoing education and training programs on quality and safety for all our employees. Supplier Standards: We maintain strict quality standards and expect quality standards from our suppliers as well. proactive protection product portfolio solution capability setting the standard Working to improve the future of power protection, I-Gard invests extensive resources on research and product development, with the goal of proactively eliminating ground and arcing faults. Recent innovations such as improved fault finding capabilities and enhanced relay functionality have been developed with this goal in mind. With extensive experience in ground fault protection, detection and location systems, I-Gard understands how ground faults can seriously affect equipment and processes. An extensive line of ground fault application solutions assist in taking the appropriate actions to ensure electrical systems are safe and properly protected. Capable of supplying a full product range, I-Gard ensures that every customer’s unique combination of budget constraints and protection requirements can be accommodated. Solutions range in scope from fully engineered turnkey systems to replacement components for existing installations. Helping to improve industrial safety standards, I-Gard is actively involved with all relevant standards agencies. Certification as an independent test facility ensures the highest level of safety without compromising delivery performance. I-Gard has been committed to quality and is currently the only resistor company in North America registered to ISO 9001:2008 since 1994. This acknowledges the high level of in-house design capabilities in addition to manufacturing expertise and customer focus. All I-Gard products are CSA certified and UL recognized and listed. 1 Reported in Power Magazine, July 1969, that the cost of arcing ground faults ranged between $1 billion and $3 billion annually for equipment loss, production downtime and personal liability. While a lot has changed in 30 years, losses due to ground faults remain a significant issue today for the industry with one leading insurance company reporting that its clients alone reported 228 losses that were attributed to ground faults with a total cost of US $180 million over a seven year period. Perhaps of greater concern are the five to 10 arc flash explosions that occur in electrical equipment everyday resulting in medical treatment. According to statistics compiled by CapSchell Inc. a Chicago-based research and consulting firm that specializes in preventing workplace injuries and deaths. The Bureau of Labor Statistics of the US Department of Labor compiles the Census of Occupational Injuries from death certificates and other information for US workers killed on the job. The 2003-2007 database shows that 1,213 workers died and 13,150 workers sustained days away from work due to occupational injuries and illnesses involving contact with electricity. technology overview WHAT IS AN ARC FLASH? An arc flash is a short circuit through the air that takes place when the insulation between electrified conductors is breached or can’t withstand the applied voltage. During an arc flash, an enormous amount of energy explodes out from the electrical equipment, sometimes causing death or severe radiation burns to employees working near energized conductors or circuits. The blast from the arc creates pressure waves that can damage hearing or brain function and a flash that can damage eyesight. I-Gard has developed methods for effectively minimizing the dangers of arc flashes through the use of high resistance grounding. At the 2003 IEEE IAS Electrical Safety Workshop it was stated that “high-resistance grounding for low voltage power distribution systems enhances reliability and uptime of power distribution equipment and is proven effective in significantly reducing the frequency and severity of arc flash accidents”. Furthermore, the NFPA 70A recognizes High resistance grounding as a mean to reduce Arc-Flash Hazards. According to a recent study by John Nelson (IEEE), high resistance grounding eliminates the hazard of arc flashes in 95% of all cases. The common cause of the losses and injuries are undetected arcing faults that occur within a facilities electrical distribution system. When an electrical system is grounded, there is an intentional connection of a phase or neutral conductor to earth for the purpose of controlling the voltage to earth, or ground, within predictable limits. It also provides for a flow of current that will allow detection of an unwanted connection between system conductors and ground (a ground fault). The root cause of this unwanted connection is often a result of insulation breakdown. 2 The majority of industrial facilities that experience arcing ground faults should not continue to operate without adequate Ground Fault Protection. These establishments typically operate an ungrounded or solidly grounded electrical distribution system, both of which have inherent disadvantages. The reasoning behind the prevalence of ungrounded systems in many industrial facilities appears to be historical. Prior to the emergence of High Resistance Grounding in the late 1980’s, the only choice when process continuity was required was an ungrounded system that allowed for the controlled shutdown for fault repairs at a convenient time, and this was of tremendous value to continuous manufacturing processes by reducing production losses, equipment damage and outages. WHAT DOES IEEE SAY ABOUT UNGROUNDED SYSTEMS? Ungrounded systems offer no advantage over high-resistance grounded systems in terms of continuity of service, and have the disadvantages of transient overvoltages, locating the first fault and burn-downs from a second ground fault. For these reasons, they are being used less frequently today than high-resistance grounded systems, and existing ungrounded systems are often converted to high-resistance grounded systems by resistance grounding the neutral. Once the system is high-resistance grounded, overvoltages are reduced and modern highly sensitive ground-fault protective equipment can identify the faulted feeder on first fault and trip one or both feeders on the second fault before an arcing burn-down causes serious damage. - IEEE Standard 242-1986 WHY CONSIDER GROUNDING YOUR SYSTEM? QA The intentional connection of the neutral points of transformers, generators and rotating machinery to the earth ground network provides a reference point of zero volts. This protective measure offers many advantages over an ungrounded system, including: Reduced magnitude of transient over-voltages Simplified ground fault location Improved system and equipment fault protection Reduced maintenance time and expense Greater safety for personnel Improved lightning protection Reduction in frequency of faults WHAT IS A SOLIDLY GROUNDED SYSTEM? A solidly grounded system is one in which the neutral points have been intentionally connected to earth ground with a conductor having no intentional impedance. This partially reduces the problem of transient over-voltages found on the ungrounded system, provided the ground fault current is in the range of 25% to 100% of the system three-phase fault current. However, if the reactance of the generator or transformer is too great, the problem of transient overvoltages will not be solved. 3 IS SOLIDLY GROUNDED SAFER THAN UNGROUNDED? While solidly grounded systems are an improvement over ungrounded systems and facilitate the location of faults, they lack the current limiting ability of resistance grounding and the extra protection this provides. The destructive nature of arcing ground faults in solidly grounded systems is well known and extensively documented. Electric arcs are caused by the energy dissipated in the fault. A measure of this energy can be obtained from the estimate of kilowatt-cycles dissipated in the arc: Kilowatt cycles = V x I x Time/1000 WHAT DOES IEEE SAY ABOUT SOLIDLY GROUNDED SYSTEMS? “The solidly grounded system has the highest probability of escalating into a phase-to-phase or three-phase arcing fault, particularly for the 480 and 600V systems. A safety hazard exists for solidly grounded systems from the severe flash, arc burning and blast hazard from any phase-to-ground fault." - IEEE Standard 141-1993 WHAT IS A RESISTANCE GROUNDED SYSTEM? There are two broad categories of resistance grounding; low-resistance and high-resistance. In both types of grounding, the resistor is connected between the neutral of the transformer secondary (or the neutral of the electrical system) and the earth (ground). HOW DO I DETERMINE WHAT SIZE OF NEUTRAL GROUNDING RESISTOR IS REQUIRED? The resistor must be sized to ensure that the ground fault current limit is greater than the system's total capacitance-to-ground charging current. If not, then transient over-voltages can occur. For more information consult I-Gard at [email protected] WHAT IS LOW-RESISTANCE GROUNDING? Low-resistance grounding of the neutral limits the ground fault current to a high level (typically 50 amps or more) in order to operate protective fault clearing relays and current transformers. These devices are then able to quickly clear the fault, usually within a few seconds. The importance of this fast response time is that it: • Limits damage to equipment, prevents additional faults from occurring, provides safety for personnel and localizes the fault • The limited fault current and fast response time prevents overheating and mechanical stress on conductors. However, like the solidly grounded neutral system, the circuit must be shut down after the first ground fault • Low-resistance grounding resistors are typically rated 400 amps for 10 seconds, and are commonly found on medium and high voltage systems 4 WHAT IS HIGH-RESISTANCE GROUNDING? High-resistance grounding of the neutral limits the ground fault current to a very low level (typically under 25 amps). It is used on medium and low voltage systems where continuity of operations is important. Most industrial distribution systems and critical facilities with distribution systems in medium and low voltage are ideal candidates for high-resistance grounding. WHY CONSIDER RESISTANCE GROUNDING? Resistance grounding is by far the most effective and preferred method. It solves the problem of transient overvoltages, thereby reducing equipment damage. It accomplishes this by allowing the magnitude of the fault current to be predetermined by a simple ohms law calculation. The fault current can be limited, in order to prevent equipment damage. Limiting fault currents to predetermined maximum values permits the designer to selectively coordinate the operation of protective devices, which minimizes system disruption and allows for quick location of the fault. WHAT DOES IEEE SAY ABOUT HIGH-RESISTANCE GROUNDED SYSTEMS? High-resistance grounding helps insure a ground-fault current of known magnitude, helpful for relaying purposes. This makes it possible to identify the faulted feeder with sensitive ground-fault relays. - IEEE Std 242-1986 7.2.4 High-resistance grounding provides the same advantages as ungrounded systems yet limits the steady state and severe transient over-voltages associated with ungrounded systems. There is no arc flash hazard, as there is with a solidly grounded system, since the fault current is limited to approximately 5A. - IEEE Std 141-1993 7.2.2 WHY LIMIT THE CURRENT THROUGH RESISTANCE GROUNDING? • To reduce burning/melting effects in faulted electric equipment, such as switchgear, transformers, cables and rotating machines. • To reduce mechanical stresses in circuits and apparatus carrying fault currents • To reduce electric-shock hazards to personnel caused by stray ground fault currents in the ground return path • T o reduce arc blast or arc-flash hazard to personnel who may have accidentally caused or who happen to be in close proximity to the fault current • To reduce the momentary line-voltage dip caused by the occurrence and clearing of a ground fault • To secure control of transient over voltages while at the same time avoiding the shutdown of a faulty circuit on the occurrence of the first ground fault Throughout the 15 to 20 years high-resistance grounding has become the standard in hazardous applications such as mining and petro-chemical, but until recently was limited in its application to industrial operations. Only recently has high-resistance grounding been adopted as the method of choice by consultants designing commercial facilities in North America (e.g. banks, data centres, hospitals, defence), and commercial facilities outnumber industrial facilities by at least a factor of twenty. 5 unparalleled protection Comparative Performance Rating For Various Conditions Using Different Grounding Methods METHOD OF GROUNDING Condition or Characteristic Ungrounded Solid Grounded Low-Resistance High-Resistance Immunity to trransient Worst Good Good Best Ground fault protection can be added Worst Good Better Best Equipment protected against arc fault Worst Poor Better Best Safety to Personnel Worst Better Good Best Service Reliability Worst Good Better Best Maintenance Costs Worst Good Better Best Continued Production: After 1st Ground Fault Better Poor Poor Best Ease of Locating 1st Ground Fault Worst Good Better Best Relay Co-ordination N/A Good Better Best 73% Increase in Voltage Stress Under Line-to-Ground Fault Conditions Poor Best Good Poor Two Voltage Levels On The Same Electrical System N/A Best N/A N/A Reduction in Frequency of Faults Worst Better Good Best 1st High Ground Fault Current Flows Over Grounding Circuit Worst Better Good Best Potential Flashover To Ground Poor Worst Good Best 6 While high-resistance grounding is the safest approach to grounding a power system, some applications may remain ungrounded (for legacy reasons) or solidly grounded – the need to provide a reference to ground or to supply single phase to neutral loads. At I-Gard we have the necessary products to cover all applications. product portfolio UNGROUNDED DISTRIBUTION PROTECTION The I-Gard VIA has been designed specifically for ground fault pre-alarm and alarm indication on high-resistance grounded or ungrounded power systems. Additionally, the VIA can detect DC ground faults that may occur on AC fed systems. One or more optional flush mounted external displays (VIA–R) can be mounted on panel doors or other locations. The isolation inside the VIA protects the external displays from high voltages. The VIA relay works on the principle of a change in line-toground voltage that occurs when a fault appears on one of the lines of the ungrounded or high-resistance grounded system. When the desire to convert to a safer high-resistance grounded system is delayed due to capital and time, a unique solution from I-Gard is the Turbo Sleuth: a portable high-resistance grounding system that temporarily and easily connects to an existing electrical system and converts the faulted system to high-resistance grounded. The Turbo Sleuth contains the fault-limiting resistor, the pulsing circuitry and if requested, an artificial neutral in a single wheeled enclosure can be added. It uses an integral pulsing circuit to facilitate fault finding while ensuring process continuity. Once the fault is located and cleared, the Turbo Sleuth is disconnected and the system is returned to its original setting. 7 SOLIDLY GROUNDED PROTECTION Today’s protection requirements demand tripping at the speed of light: The new Sentri includes three light sensor inputs, that provide the Sentri with the ability to trip solid state relays at the speed of light to protect personnel and equipment from arc flash hazards, by tripping faster than any other commercial relay. sentri light sensors To provide a total solution and coordination with other devices, Sentri relay, range in trip levels from 10mA up to 1200A, in a single format. This versatile relay can be used in solidly grounded and resistance grounded systems. Too often, systems are protected with just one relay on the main service breaker, which leads to power interruption of the entire service if a ground fault occurs in any location. Consequently, in an effort to minimize disruptions, the protection on the main breaker is often set to maximum pickup and delay settings, or worse, disconnected entirely. This can lead to substantial equipment damage, due to increased clearing time. Minimizing damage, downtime and maintaining service, the Sentri relays with integral Zone Selective Instantaneous Protection to protect systems, at LV and MV system levels, with optimized coordination. Maximum protection with minimum service disruption. LOW-RESISTANCE GROUNDING PROTECTION I-Gard offers a complete range of Neutral Grounding Resistors (NGR) from 277V to 115 kV that are used for resistance grounding of industrial power systems and are usually connected between earth ground and the neutral of power transformers, power generators or artificial neutral transformers. NGR's limit the maximum fault current to a value which will not damage generating, distribution or other associated equipment in the power system, yet allow sufficient flow of fault current to operate protective relays to clear the fault. Along with our CSA category certification for NGR products, all our NGR's are built to IEEE Standard 32, featuring line-to-line rated standoffs that provide triple insulation to ground. I-Gard has standardized on edgewound element design for NGR’s to deliver superior and more consistent performance. 8 HIGH RESISTANCE GROUNDING PROTECTION LISTED FEATURES OF I-GARD HRG PRODUCTS Sleuth Gemini Sentinel Gardian NGR Enclosed X X X X GF Alarm X X X X GF Pulsing X X X X Resistor Monitoring X X X Dual Path Resistor X X Feeder Indication X X 2nd Fault Protection X X Arc Flash Mitigation X DSP-OHMNI SYSTEM DSP Second Fault Protection – unnecessary outages of electrical power in continuous process industries or in critical systems applications such as hospitals and air traffic control towers, cannot be tolerated and this has increased the usage of high resistance grounding systems. The new DSP-OHMNI is designed to provide an alarm, but not trip when one ground fault occurs in the system- thus retaining system continuity. If a second phase to ground fault develops on the system, before an existing fault has been cleared, then the potential for serious damage results. The DSP is the only relay to offer second fault protection through the SIFT system (Selective Instantaneous Feeder Trip). Enabling the user to prioritize the feeders and upon the occurrence of a second fault on a different phase, select which feeder will instantaneously trip. Fault finding is made even easier with the new optional pulsing module. The new generation DSP now offers resistor monitoring through the DRM module and ModBus communication to facilitate remote communication and management. The new digital display makes the alarm and metering information more useful and easier to read. 9 With significant expenditure dedicated annually to product development and application research, I-Gard leads the way in bringing innovative new products to market with a commitment to reducing electrical hazards. safety through innovation SUPERGRID The SuperGrid product enables the user to dissipate up to 6 times the wattage of an industry standard grid and is ideal for heavy applications where space is a premium. A standard NEMA grid bank dissipates approximately 2kW of power where the patented SuperGrid typically dissipates around 12kW per bank. When Bombardier needed a heavy duty resistor for their test track in Thunder Bay they decided on the patented SuperGrid. Patent 5,917,404 m-GARD RELAY The m-GARD is a microprocessor based ground fault relay designed and built to be used on solidly or resistance grounded systems. This innovative digital electronic relay measures ground fault current using built-in Zero Sequence Current Sensor (ZSCS), with the ability to operate on any control voltage supply, it reacts to alternating current only and will reject direct current signals. With the harmonic filtering feature enabled, the m-GARD provides the reliability required by modern power systems with variable frequency drives. The m-GARD-SYM remote indicator provides detailed device status information, remote test/reset and Modbus connectivity for up to 50 I-Gard relays with an isolated connection to an external Modbus RTU network. All 50 devices can be monitored remotely using a single configurable Modbus address. 10 SIGMA RELAY A combination of an NGR monitor and ground fault relay. It provides adjustable pickup level and adjustable definite time delay for the ground current. In resistance grounded systems, the NGR is constantly monitored to ensure that the 3-phase 3-wire distribution system remains fault free. SIGMA is designed for use on any resistance grounded system that requires continuous monitoring of the NGR. A separately mounted sensor measures the ground current and the voltage across the NGR. The values measured are compared with settings and trip and alarms are indicated when an abnormal condition is detected. GROUND CHECK MONITOR In our continuing effort to bring new and innovative products to the electrical industry that provide additional safety and performance benefits to the user, I-Gard has developed a state-of-the-art protection relay for mobile trailing equipment, that protects operators from electrical shock. The level of safety provided is enchanced through the addition of AC touch voltage protection, the only relay in the market with this feature. focus on quality In addition to ISO standards for manufacturing quality, there are a number of product specific guidelines and application standards from CSA, UL and IEEE covering power resistors and ground fault protection products including: UL-508, CSA 22.2 No. 14 for NGR's below 1.5 kV, for those above 5 kV UL-347 and the CSA22.2 TIL-D-31. High-resistance grounding systems comply with UL-891 in addition to CSA 22.2 No. 14. Our relays are listed under UL-1053, CSA 22.2 no. 144 and those used for people protection under UL-943. Mining Relays comply with M421-00. 11 Our focus on quality and testing is exemplified by our CSA approved test facility that permits I-Gard to develop and verify prototype resistors and relays and is reinforced through our product category certifications. All of our resistors elements and protective relays are both CSA certified and UL recognized and listed. commitment to standards CSA International 2002 C22.1 No. 02 Canadian Electrical Code Part 1. C22.2 No. 14-95 1995 (2001) T.I.L. No. D-21 1995 C22.2 No. 144-M91 1991 (1997) M421-00 2001 Industrial Control Equipment Industrial Control Equipment No. 2 Ground Fault Circuit Interrupters Use of Electricity in Mines Underwriters Laboratories inc. UL508 1999 Industrial Control Equipment UL347 1993 High-Voltage Industrial Control Equipment UL508C 1996 Power Conversion Equipment UL50 1995 Enclosures for Electrical Equipment UL943 2005 Ground Fault Circuit Interrupters National Fire Protection Association NFPA 70E 2005 National Electrical Code Institute of Electrical & Electronics Engineers IEEE Std 32 1972 Neutral Grounding Devices IEEE Std 141 1999 Recommended Practice for Electric Power Distribution for Industrial Plants IEEE Std 142 1991 Recommended Practice for Grounding of Industrial and Commercial Power Systems IEEE Std 241 1997 Recommended Practice for Electric Power Systems in Commercial Buildings IEEE Std 242 1991 Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems 12 Our reputation as the industry expert in Ground Fault Protection is hard earned and continually supported. Whether we are providing Contracting Tips to Electrical Business to improve the contractor’s understanding of High-Resistance Grounding and how to upgrade an ungrounded facility or partnering with EC&M on their “Ask the Expert” program as their expert in Ground Fault Protection or delivering educational seminars at IEEE conferences, our team of experts provides a depth and breadth of application knowledge that is unmatched in the industry. recognized as experts “ASK THE EXPERT” Over the years I-Gard had partnered with Electrical Construction and Maintenance in a campaign to address questions their readers would have on ground fault protection. Today, our applications experts continue to raise awareness on the safety and importance on high-resistance ground and ground fault protection directly from our website www.i-gard.com. Submitting a question and addressing the issue has never been easier. I-Gard is here to help in providing ground fault protection solutions that suit and surpass your expectations. unparalleled protection INDUSTRY EDITORIALS In conjuntion with industry leading trade magazine such as EC&M, Electrical Business, Electricity Today, International Association of Electrical Inspectors e.t.c., I-Gard has furthered the understanding of the hazard of arcing faults as well as the benefits and applications of high-resistance grounding through a number of educational editorials. 13 application guides Our Application and Specification guides, relied on by consultants, end-users and contractors, are constantly being updated with the latest innovations. The following guides below are available for download from the I-Gard website www.i-gard.com. Select the Technical Library link and then select Application Guides. Neutral Grounding Resistors Technical Information Ground Fault Protection on Ungrounded & HighResistance Grounded Systems Ground Fault Protection for Solidly Grounded Systems Application Guide Application Guide Application Guide Ground Fault Protection High-Resistance Grounding Ground Fault Protection Ungrounded Systems to High-Resistance Grounding Consultant Specification Guide Conversion Guide 14 our production facility With our focus on quality and flexibility, along with a manufacturing operation that has embraced lean manufacturing principles; we provide industry leading service and quality levels. Our experienced, well trained and empowered workforce process every order with the care and attention expected to ensure it is manufactured and shipped on time, and to the highest quality level. 3 SOLUTIONS & FACTS ABOUT I-GARD I-Gard offers more HRG products at more price points than any other competitor in the industry, with customizable solutions for your specific application. I-Gard is the exclusive supplier of FAIL-SAFE and SMART HRG systems with 2nd ground fault protection to better match your need for electrical reliability and safety. I-Gard Electronic Assembly Area, where the entire range of ground fault products are manufactured and tested and where new product development is undertaken in dedicated work cells. We are the only HRG supplier that also offers optical arc mitigation for Total Protection against ground faults and arc flash incidences. how to get in touch Corporate Office 7686 Bath Road Mississauga, Ontario Canada L4T 1L2 Phone: 905-673-1553 Fax: 905-673-8472 Toll Free: 1-888-737-4787 [email protected] 15 Phone: 905-673-1553 Toll Free: 1-888-737-4787 Fax: 905-673-8472 [email protected] www.i-gard.com
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