Surge Protection. For Business-Critical Continuity TM. Surge Protection. Reference Guide

Transcription

1 Surge Protectio For Busiess-Critical Cotiuity TM Surge Protectio Referece Guide

2 PROTECT YOUR INVESTMENT BY PROTECTING YOUR POWER Compaies sped billios of dollars o equipmet ad facilities every year. But few of them realize that this ivestmet is at risk if the power source is ot properly protected. This guide will explai the importace of protectig your power, idetify the challeges ad solutios for power protectio, describe the quality stadards ad applicatios ivolved, ad much more.

3 Table Of Cotets The Importace Of Protectig Your Power...2 A Growig Need...2 Power Quality: Keepig It Clea...3 What Makes Power Dirty? Types Of Power Disturbaces...3 Examples Of Power Disturbaces Ad Solutios...4 The Impact Of Power Disturbaces...4 Cosequeces Of Trasiet Damage...5 The Beefits Of Power Quality Ad Protectio Products...5 Safety Agecies Recogize The Need For Power Quality Products...6 Excerpts From IEEE Stadard Power Quality Stadards...8 Why We Need Stadards...8 Surge Suppressio Stadards Overview...8 UL Stadards...9 Istitute Of Electrical Ad Electroics Egieers (IEEE) Stadards...10 Natioal Electrical Code (NEC) Ad Natioal Fire Protectio Associatio (NFPA) Surge Protectio Devices...14 Types Of Protectio...14 AC Power Protectio...14 A Quick Overview Of Protective Devices...14 Oe-Port Parallel-Coected Devices...14, 15 Two-Port (Series-Coected) Devices...16 Usig Surge Suppressio To Cotrol High-Voltage Trasiets...17 Usig Active Trackig To Cotrol Low- Ad High-Voltage Trasiets...17 DC Low Voltage Surge Protectio...18 Compoets Of A Surge Protector...19 Selectig the Right Power Quality Device...20 Start With The Big Questios...20 Istallatio Cosideratios...20, 21 Idustry-Specific Applicatios...22 Who Needs To Protect Their Power?...22 Idustries That Beefit From Power Protectio...22 Spotlight O Healthcare...22, 23 Spotlight O Telecommuicatios...23 Spotlight O Fire/Alarm/Security...23 Spotlight O Trasportatio...24 Spotlight O Data Ceters...24 Typical Questios...25 AC Power Surge Protective Devices (SPDs) Low Voltage Protectio...28 The Emerso Advatage...29 Put The Power Of Emerso To Work For You...29 Emerso The Global Techology Leader...29 Emerso Network Power: Eablig Busiess-Critical Cotiuity...29 Emerso Network Power Surge Protectio: Surge Specialists...30 The Brad You Ca Cout O...30 Glossary Of Terms...31, 32 1

4 The Importace Of Protectig Your Power A Growig Need Today, we re seeig dramatic icreases i the use of electroic equipmet, cotrols, ad processes i most idustries. Tools ad equipmet are becomig electroically-based as factories become more automated ad process-itesive. I may cases, the mechaical aspects of these processes, such as spidle acceleratio, coveyor speed, extruder flow, or spray pressure, caot tolerate variatios caused by mometary voltage fluctuatios. Ad of course, the proliferatio of PCs, priters, copiers, ad electroic commuicatios has affected the commercial market while everythig from microwaves 70% of electrical threats are iterally geerated to home-etertaimet systems are placig icreased demad o the power eeds for the residetial sector. May of these electroics are also sesitive to voltage variatios that were ot oticed i the past. With more electroics i the power system tha ever before, ad all idicatios poitig to cotiued icreases, the questio becomes: ca the power supply as it is curretly desiged hadle this icreased load? For us, the solutio is to esure that the power you re usig is clea, ad able to keep your equipmet operatig properly. ay coductive circuit withi a few miles of a lightig strike ca still experiece a several-thousad-volt trasiet 2

5 Power Quality: Keepig It Clea We refer to power quality as clea (good) or dirty (bad). Power quality is measured by the iteractio of electric power with electrical equipmet. Good-quality clea power is critical to esure a uiterrupted supply of electricity that does ot cause damage or dowtime. If your electrical equipmet operates reliably ad properly without stress, damage, fatigue, or impact o processes your power is clea. O the other had, if your electrical equipmet is damaged, ureliable, or malfuctioig, your power quality may be dirty. Dirty power has the potetial to affect your compay s bottom lie i a myriad of ways: Lost productivity Icreased dowtime Greater capital expeditures o equipmet repair ad replacemet Budget surprises Agry customers Lost busiess ad reveue What Makes It Dirty? Types Of Power Disturbaces There are three Ds that affect power quality: degradatio, disruptio, ad destructio. Power disturbaces may be called a surge, sag, spike, swell, trasiet, fluctuatio, iterruptio, or electrical lie oise. All these disturbaces are abormalities ad deviatios from the ormal performace of voltage sources. They may last for a short period, a log time, or be cotiuous. Approximately 70% of electrical threats are iterally geerated by trasiets ad electrical lie oise, such as dips ad iterruptios, electrostatic discharge ad surges. The remaiig 30% of issues ca be attributed to variatios i the power supplied by utilities caused by lightig, outages, over- ad uder-voltages, ad swells/sags. I fact, lightig strikes are probably the most destructive example of a high-voltage trasiet: a direct hit ca deliver thousads of volts ad amperes. But lightig does ot have to strike your facility to do sigificat damage. Via mutual iductio, ay coductive circuit withi a few miles of a lightig strike ca still experiece a several-thousadvolt trasiet, leavig electrical service etrace paels vulerable to power surges. Ad, as we ll see later, you may have effective surge protectio at your service etrace pael, but this does ot exempt you from potetial equipmet damage i a evet like this. Utility switchig is aother type of power disturbace that ca lead to compromised power quality. The path of electrical power from a utility geerator to a commercial buildig is ot a dedicated lie it s a etwork of geerators ad substatios itercoectig may facilities over hudreds or thousads of miles. Frequet chages i electrical demad or other service requiremets ofte result i the switchig of etwork grid tie poits. Each time a substatio is switched i or out of the etwork, a voltage trasiet is produced that ca reach hudreds or thousads of volts, depedig o the curret, impedace, ad facility distace from the switchig poits. Capacitor switchig ca have a similar egative effect. Utilities ad large commercial power users add power factor correctio capacitors to a etwork to compesate for excessive iductive loads (e. g. motors) ad boost power at the distributio extremities. Baks of capacitors are typically switched o at the same time every morig ad switched off at the same time each ight. Whe switchig occurs, trasiets ca reach hudreds or thousads of volts, depedig o the impedace or distace of the affected equipmet from the capacitor baks. Faults o a utility s distributio system ca geerate surges. Damagig voltage trasiets ad electrical lie oise ca be itroduced by usig elevators, air-hadlig equipmet, or eve arc welders i costructio projects that are close to other buildigs. The mere operatio of air-coditioig systems, PCs, telephoe systems, or other electroics ca damage sesitive microelectroics i products that share the same lie. Daily fluctuatios from iteral electrical equipmet such as a copier that gets tured o ad off frequetly ad rus i cycles ca cause cumulative damage. The more electrical equipmet your compay uses, the more trasiets accumulate to create potetial power disturbaces ad damage. 3

6 The Importace Of Protectig Your Power (Cotiued) Examples Of Power Disturbaces Ad Solutios As you ve see, there are may sources of power disturbace, from RF to groud faults, to utility switchig ad more. Below is a chart outliig may of these coditios, alog with defiitios, sources of the disturbaces, ad solutios. POWER CONDITION DEFINITION SOURCES SOLUTION Electrical Lie Noise Low to high amplitude, low curret, ad high frequecy disturbaces. Cosists of impulses (amplitude of up to 50 volts) ad EMI/RFI oise (amplitude of millivolts to several volts). Radio trasmissio Normal computer operatio Arcig cotacts Lightig Poor groudig ad shieldig Switchig power supplies Motor speed cotrollers Low Pass Filter or Active Trackig Filter Trasiets ad Impulses High voltage/high curret, low frequecy disturbace. Amplitude of 50 volts to as high as several thousad volts. Duratio is typically less tha a millisecod. Switchig loads o ad off Utility switchig Lightig Fault clearig SPD Harmoics A cotiuous distortio of the ormal sie wave, of frequecies that are multiples of the operatig frequecy. Switchig loads Normal computer operatio Harmoic Filter Overvoltage Abormally high or low voltage coditios lastig for more tha a few secods. Utility switchig Rapid load reductio Voltage Regulator Udervoltage Abormally low voltage coditios lastig for more tha a few secods. Groud faults Startig large loads Iadequate power system capacity Utility switchig Utility equipmet failure Lightig Voltage Regulator Voltage Swell A high-voltage coditio o oe or more phases. Voltages above 110% of omial voltage. Duratio is 0.5 to 1 miute. Utility switchig Rapid load reductio Voltage Regulator Voltage Sag A low-voltage coditio o oe or more phases. Voltages betwee 90% ad 10% of omial voltage. Duratio is 0.5 to 1 miute. Groud faults Startig large loads Iadequate power system capacity Utility switchig Utility equipmet failure Lightig Voltage Regulator Outage or Dropout A zero-volt coditio lastig loger tha a half cycle. The Impact Of Power Disturbaces Groud faults Equipmet failure Accidets Utility equipmet failure Lightig Differet types of dirty power ca affect electrical loads, resultig i a umber of problems, as show below: UPS Impact to Electrical Loads Electrical Lie Noise Small Trasiets 2x Nomial Voltage Large Impulses 4x Nomial Voltage Circuit Board Failure Yes Yes Data Trasmissio Errors Yes Yes Yes Memory Scramble Yes Yes Yes Hard Drive Crash Yes SCR Failure Yes System Iterruptio Yes Yes Yes Power Supply Failure Yes Yes Program Lock Up Yes Yes Yes Source: The Draetz Field Hadbook for Power Quality Aalysis 4

7 Cosequeces of Trasiet Damage Trasiet damage is electroic rust that gradually eats away at the circuit traces that allow electricity to flow betwee electroic compoets o a prited circuit board of a computer, priter, or other device. Hard drive crashes, data trasmissio errors, ad circuit board failures are just some of the cosequeces of electroic rust. If uchecked, it will evetually stop a computer i its tracks. See through a microscope, this damage deep iside a chip is electroic rust. You ca t see electroic rust i actio, but it s slowly eatig away at your computer. If you do t idetify issues with low-eergy trasiets ad/ or high-frequecy electrical lie oise early, the you will certaily experiece problems over time, as evideced i these photos. Electroic rust does t cause sudde catastrophic failures it works much more slowly but it ca do just as much damage. Gradually eatig away at sesitive circuits, electroic rust icapacitates circuitry. Electroic rust gradually eats away at the circuit traces The Beefits Of Power Quality Ad Protectio Products To maitai high-quality power withi your facility, you must start with a solid foudatio. This begis by esurig that the wirig, groudig, ad bodig are up to stadards. Oce you ve verified this, you ca istall elemets such as surge protectio devices (SPDs), low-pass filters, ad data ad sigal lie protectors to prevet damage from surges ad electrical lie oise. To improve your facility s uptime, you should cosider uiterruptible power supplies (UPS), voltage regulators, ad geerators. Improved Uptime Damage Prevetio Voice/Data/Sigal Lie Protectors Low-Pass Filters SPD Redudacy Moitorig Maiteace UPS Geerators Isolatio Xfmr Voltage Regulators Wirig Groudig Bodig Ivestmet Dollars $$$ 5

8 The Importace Of Protectig Your Power (Cotiued) Safety Agecies Recogize The Need For Power Quality Products 8.6 Lightig/surge protectio cosideratios: a listed ad properly rated surge protective device should be applied to each idividual or set of electrical coductors (e.g., power, voice, ad data) peetratig ay of the six sides formig a structure. 6

9 Excerpts From IEEE Stadard , The Emerald Book: IEEE Recommeded Practice For Powerig Ad Groudig Electroic Equipmet Surges: If lightig strikes o or ear overhead electric power or telephoe lie, a large curret will be ijected ito or iduced i the wires, ad the curret ca do cosiderable damage both to the power ad telecommuicatios equipmet ad to aythig else that is coected to the system Surges ca have may effects o equipmet, ragig from o detectable effect to complete destructio electroic devices ca have their operatio upset before hard failure occurs. The semicoductor juctios of electroic devices are particularly susceptible to progressive deterioratio few solid state devices ca tolerate much more tha twice their ormal ratig. Furthermore, data processig equipmet ca be affected by fast chages i voltage with relatively small amplitude compared to the hardware-damagig over-voltages For large surge currets, this diversio is best accomplished i several stages. The first diversio should be performed at the etrace to the buildig a secod protective device at the power pael Potetial impact of EMI: Depedig o the severity of the surge ad the susceptibility of the equipmet, three types of occurreces are possible : data disruptio, hardware stress, ad hardware destructio EMI, Type I, sigal-data disruptio: Sigalcarryig circuits are susceptible to surge iterferece via coductio, iductive ad capacitive couplig, ad electromagetic radiatio EMI, Type II, gradual hardware stress ad latet failures: A sigle lightig or switchig surge ofte causes immediate, but ot readily apparet physical damage to semicoductor devices. This damage the fially appears at some later time EMI, Type III, immediate hardware destructio: The third possible impact of surges is the immediate obvious ad total destructio of hardware compoets i a sigle icidet Surge suppressors: Effective surge protectio requires the coordiated use of large-capacity curretdivertig devices at the service etrace followed by progressively lower voltage-clampig devices. 8.6 Lightig/surge protectio cosideratios: A listed ad properly rated surge protective device should be applied to each idividual or set of electrical coductors (e.g., power, voice, ad data) peetratig ay of the six sides formig a structure Selectio: Surge protective devices for threephase, four-wire circuits are geerally recommeded to be coected i all combiatios of lie-to-lie, lie-toeutral, lie-to-groud, ad eutral-to-groud Istallatio: Recommeded istallatio practice is for all lead legths to be short ad shaped to miimize ope loop geometry betwee the various coductors by twistig all the phase, eutral, ad equipmet groudig coductors together; ad by avoidig ay sharp beds ad coils i the coductors Service etrace surge protectio: Facilities housig electroic load equipmet of ay type should have service etraces equipped with Category C surge protective devices, as specified i IEEE Std C Premise electrical system surge protectio: recommeded that additioal surge protective devices of listed Category B or Category A, as specified i IEEE Std C , be applied to dowstream electrical switchboards ad paelboards, ad paelboards o the secodary side of separately derived systems if they support commuicatios, iformatio techology equipmet, sigalig, televisio, or other form of electroic load equipmet UPS system surge protectio: It is recommeded practice that both the iput circuit to the UPS ad the associated bypass circuits (icludig the maual bypass circuit) be equipped with effective Category B surge protective device Data/commuicatio/telecommuicatio systems surge protectio: Electroic equipmet cotaiig both ac power ad data cablig should also be properly protected via surge protective devices o both the ac power ad data cables Exterior buildig systems ad pipig lightig/ surge protectio: All exterior mechaical systems (e.g., coolig towers, fas, blowers, compressors, pumps, ad motors) should be cosidered targets for a lightig strike. it is recommeded practice to idividually provide surge protective device protectio o both the power iput ad data circuits coected to all such equipmet. 7

10 Power Quality Stadards Why We Need Stadards Techical stadards are developed by paels of experts, ad desiged to be idepedet of proprietary products or specific vedors. These stadards are the maitaied ad revised as eeded by the orgaizatio that issues them (e. g., Uderwriters Laboratories). Natioal ad iteratioal product safety stadards ad guidelies are created to: Reduce risks to huma health ad safety. Improve the quality of maufactured goods ad services. Promote iteroperability, makig it possible for equipmet from oe vedor to fuctio efficietly i coordiatio with equipmet from other vedors. Improve the efficiecy of costructig ad equippig idustrial, medical, ad commercial facilities. Result i cosistet products ad reliable maufacturig ad safety processes. Improve evirometal protectio where stadardscompliat products are istalled. Surge Suppressio Stadards Overview Whe it comes to SPDs, specific stadards are developed by Uderwriters Laboratories (UL) ad the Natioal Fire Protectio Associatio. Over the last several years, there have bee may chages i the codes ad stadards for SPDs. The most sigificat are chages to UL There is also a ew stadard for safety, of surge protective devices (article 285), which ivolves chages to the Natioal Electric Code. This stadard specifies the waveforms to be used i testig America-maufactured SPDs, defies termiology related to SPD maufacture ad test procedures, establishes proper labelig for SPD products, ad specifies required testig ad miimum acceptable performace. Previous versios of UL 1449 idetified oly two types of SPDs: permaetly coected or cord-coected. The third editio of UL 1449 has combied all categories ito a formal classificatio ad idetified them as four differet types, each of which has cosistet testig ad applicatio requiremets. The most commo SPDs geerally fall ito Type 1 ad Type 2 categories. UL Stadards ANSI/UL 1449 Third Editio: Stadard for Trasiet Voltage Surge Suppressors (SPDs) 8

11 Type 1 SPDs are Secodary Surge Arresters ad are istalled betwee the secodary side of a service trasformer ad the primary side of a service etrace discoect. They must have overcurret protective devices either istalled iterally o the SPD or icluded with it. While these are primarily iteded for istallatio before the mai service discoect, Type 1 SPDs ca be istalled i Type 2 ad Type 4 locatios such as distributio paels, ed-use equipmet, etc. Type 2 SPDs are iteded to be coected o the secodary side of the mai service discoect. While some will have iteral overcurret protective compoets, Type 2 SPDs ca rely o the service etrace overcurret discoect device for over curret protectio. These ca be istalled i service equipmet, distributio paels, ad ed-use equipmet. Type 2 SPDs are permaetly coected. Type 3 SPDs are iteded to coect at least 33 feet from the service etrace; this does ot iclude the legth of the SPD coductors. These devices are cord-coected devices, ad iteded to be used i ed-equipmet locatios. They ca rely o exteral overcurret protective devices for overcurret protectio. Type 3 SPDs that are cord-coected are required to comply with the leakage curret requiremets to esure uwated (objectioal) currets are ot ijected o the groud coductor. Type 4 SPDs are compoet or assembly drives. They are icomplete i their costructio or safety testig (e. g., limited-curret abormal overvoltage test, itermediate curret tests) ad are iteded to be tested i the fial assembly. Those that are icomplete i costructio or testig have the idetifyig iformatio oted i the requiremets sectio of the maufacturer s UL report. Ufortuately, there is o documetatio of the additioal testig requiremets for a Type 4 SPD o the labelig or istallatio istructios. These ca rage from sigle compoets (MOVs, SADs) to complex devices iteded for istallatio ito distributio equipmet (pael boards, switchboards, etc.). There s also a Nomial Discharge Curret ratig up to 20kA. This is part of the Voltage Protectio Ratig test ad is a measure of the SPD s edurace capability. Maufacturers will choose the applicable ratig ad show the data o literature, specificatios, ad products. Additioal importat UL stadards addressig surge protectio iclude: UL 1283: Electromagetic Iterferece Filters This documet establishes requiremets for electromagetic iterferece (EMI) filters. It covers filters istalled o, or coected to, 600 V or lower potetial circuits, Hz, accordig to the Natioal Electrical Code (NEC). These factory-istalled filters are used to atteuate uwated radio frequecy (RF) sigals, such as oise or iterferece geerated from electromagetic sources. These filters cosist of capacitors ad iductors used aloe or i combiatio with each other ad may be provided with resistors. This category does ot cover SPDs or EMI filters for outdoor use, but does iclude: Cord-coected filters these are provided with a supply cord that has a attachmet plug that coects the filter to a brach circuit receptacle. It also has a receptacle for distributig the filtered voltage to a exteral load (a appliace or other equipmet). Direct plug-i filters these have blades at the filter body that plug directly ito a 15A, 120 V brach circuit receptacle. Like the cord-coected filter, it icludes a receptacle for distributio of the filtered voltage to a exteral load (a appliace or other equipmet). Facility filters these are istalled as part of the electrical service, feeders, or brach circuitry of a buildig wirig system. UL 497 Series: Protectors For Fire Alarm Sigalig Circuits This establishes performace stadards ad testig procedures for eclosures, corrosio protectio, fieldwirig coectios, ad compoets of SPDs, as well as product labelig ad istallatio istructios. I additio to the ew categorizatio, ANSI/UL 1449 Third Editio specifies that surge suppressio products formerly idetified as Trasiet Voltage Surge Suppressor (TVSS) will be called Surge Protective Devices (SPDs). It modified the Suppressed Voltage Ratig (SVR) test from 6kV, 500A to 6kV, 3,000A, which represets six times more surge curret. Ad let-through voltage is ow termed the Voltage Protectio Ratig (VPR). 9

12 Power Quality Stadards (Cotiued) Istitute Of Electrical Ad Electroics Egieers (IEEE) Stadards The IEEE develops stadards ad guidelies for recommeded practices for a broad rage of idustries, icludig biomedical/healthcare, iformatio techology ad assurace, power ad eergy, telecommuicatios, ad trasportatio. IEEE has a trilogy of guides that address the surge eviromet, characterize surges, ad defie surge testig i low-voltage AC power circuits. IEEE C (2002): Guide O The Surge Eviromet I Low-Voltage (1000V Ad Less) AC Power Circuits This first guide provides comprehesive iformatio about surges ad the eviromet i which they occur. It describes the surge voltage, surge curret, ad temporary overvoltages (TOV) eviromet i low-voltage (up to 1000V root mea square [RMS]) AC power circuits. It is a referece for the secod documet, which describes the surge eviromet. IEEE C (2002): Recommeded Practice O Characterizatio Of Surges I Low-Voltage (1000V Ad Less) AC Power Circuits This secod guide presets recommedatios for selectig surge waveforms, ad the amplitudes of surge voltages ad currets used to evaluate equipmet immuity ad performace of SPDs. Its recommedatios are based o the locatio withi a facility, power lie impedace to the surge, total wire legth, proximity, type of electrical loads, wirig quality, ad more. The documet describes typical surge eviromets ad does ot specify a performace test. The waveforms icluded i the documet are meat as stadardized waveforms that ca be used to test protective equipmet. IEEE C62.45: Recommeded Practice O Surge Testig For Equipmet Coected To Low-Voltage (1000V Ad Less) AC Power Circuits This third guide i the trilogy focuses o surge testig procedures usig simplified waveform represetatios (described i IEEE C ) to obtai reliable measuremets ad ehace operator safety. This guide provides backgroud iformatio that helps determie whether equipmet or a circuit ca adequately withstad surges. However, it does ot address sigal ad data lies, or specify the withstad levels that might be assiged to specific equipmet Lightig-iduced surges. As may as 40 retur strikes have bee observed (see McCa [B43]). Their currets rage from a few hudred amperes to more that 500 ka, as show i Figure 4-9. I much of North America, 20 ka to 40 ka is the value that is ofte used to estimate typical lightig curret coditios. The typical strike duratios last 50μs to 100μs Surge suppressors: Effective surge protectio requires the coordiated use of large-capacity curretdivertig devices at the service etrace followed by progressively lower voltage-clampig devices. 8.1 Recommeded desig/istallatio practices: Desired performace of electroic load equipmet typically depeds o various items, such as the proper selectio ad arragemet of the electrical distributio system, the proper selectio ad istallatio of electrical distributio equipmet, the proper selectio ad istallatio of a groudig system for both the electrical power system ad the electroic load equipmet, ad the proper selectio ad applicatio of surge protective devices (SPDs) Istallatio: Recommeded SPD istallatio practice is for all lead legths to be short ad shaped to miimize ope-loop geometry betwee the various coductors by twistig all the phase, eutral, ad equipmet groudig coductors together; ad by avoidig ay sharp beds ad coils i the coductors. 9L Damage caused by SPDs: SPD overcurret protectio is the most importat (ad ofte overlooked) aspect of reliability ad safety. Ay SPD compoet ca fail, ope or shorted, due to surge voltage stress or temporary overvoltage (TOV) stress (such as a lost eutral). This TOV stress causes may more SPD failures tha actual trasiet surges. The result may be smoke, fire, or explosio for some of the metal-oxide varistor (MOV) based SPDs. This occurs regularly i real world SPD istallatios, but ca be cotrolled with compoet level fusig or thermal fusig. Doe properly, this fusig will iterrupt excessive cotiuous curret through the compoet, iterrupt available utility fault curret, ad yet pass trasiet curret. Compoet level fusig i a SPD ca provide a fail-safe system prevetig catastrophic failure or complete loss of protectio. 10

13 Natioal Electrical Code (NEC) Ad Natioal Fire Protectio Associatio (NFPA) Developed by the NFPA, the NEC was established i 2002 to address electrical safety i the workplace. While the code is updated every three years, ot all states ad muicipalities have adopted the same versio of the NEC. The 2005 revisio of the NEC had two types of SPDs: secodary surge arrestors ad trasiet voltage surge suppressors (ow called SPDs). Article 285 Whe UL ad the America Natioal Stadards Istitute (ANSI) adopted the Stadard for Safety, Surge Protective Devices, some chages were required to the NEC. I the 2008 revisio of the NEC, you ll ow fid the requiremets for coectig all SPDs rated 1000V or less to the electrical distributio system of a facility. The SPD s locatio rages from secodary termials of the service trasformer to ed-use equipmet. The stadard addresses surge protectio to help electricias properly istall hardwired SPDs. It also provides guidelies for electrical ispectors to esure proper safety ad fault curret coordiatio where SPDs are istalled. Article This requires every SPD to be marked with a short circuit curret ratig (SCCR). This ratig must be equal to or greater tha the available fault curret preset at the poit where the SPD is istalled o the system. This documet provides maufacturers ad specifiers with guidelies to describe ad compare low-voltage (less tha 1000V RMS) SPDs usig a uiform termiology ad formats. It also outlies essetial ad measurable SPD parameters usig off-the-shelf testig equipmet ad referecig established stadards defied by the IEEE ad America Natioal Stadards Istitute (ANSI)/UL. Article cosists of three sectios: Specificatios, itroductio, ad defiitios. Selectio ad applicatio criteria. Test ad evaluatio procedures. Please ote that these are guidelies oly; this documet does ot itroduce ew stadards or test methodologies, or does it defie a extesive vocabulary for SPDs. Article NEC Article (B) requires surge suppressor coectig coductors to be at least #14 copper or #12 alumium. Accordig to the Natioal Electric Code, Type 1 SPDs should be istalled as follows: Type 1 SPDs are permitted to be coected to the supply side of the service discoect as permitted i (4) or Type 1 SPDs are permitted to be coected i Type 2 locatios as specified i Whe istalled at the services, the groudig coductor of a Type 1 SPD shall be coected to oe of the followig: (1) Grouded service coductor (2) Grouded electrode coductor (3) Groudig electrode for service (4) Equipmet groudig termial i the service equipmet Type 2 SPDs (LPGE, HA Series) should be istalled i accordace with Service Supplied Buildig or Structure. Type 2 SPDs shall be coected aywhere o the load side of a service discoect overcurret device required i , uless istalled i accordace with (8). Feeder-Supplied Buildig or Structure. Type 2 SPDs shall be coected at the buildig or structure aywhere o the load side of the first overcurret device at the buildig or structure. Separately Derived System. Type 2 SPDs shall be coected o the load side of the first overcurret device i a separately derived system. Article This idetifies the applicable istallatio locatios for a Type 1 SPD. These are allowed to be istalled o the supply side or lie side of a service discoect. Whe these SPDs are istalled o the supply side, the groudig coductor must be coected to either the grouded service coductor, the groudig electrode coductor, the groudig electrode for the service, or the groudig termial i the service equipmet. (Cotiued) 11

14 Power Quality Stadards (Cotiued) Natioal Electrical Code (NEC) A d Natioal Fire Protectio Associatio (NFPA) (Cotiued) Article This idetifies the applicatio requiremets ad istallatio locatios for a Type 2 SPD. These SPDs are permitted to be istalled oly o the load side of the service discoect overcurret device. I istallatios with multiple buildigs or structures, a Type 2 SPD ca oly be istalled dowstream of the first overcurret device. O separately derived systems, these SPDs must be coected o the load side of the first overcurret device. Natioal Fire Protectio Associatio (NFPA) 780 Lightig Protectio Code NFPA 780 addresses the protectio requiremets for ordiary structures, miscellaeous structures, special occupacies, idustrial operatig eviromets, etc. It requires that devices suitable for protectig the structure be istalled o electric ad telephoe service etraces, ad o radio ad televisio atea lead-is. Iteratioal Electrotechical Commissio (IEC) As the primary trade orgaizatio for all electrical, electroic, ad related techologies, the IEC publishes ad assesses compliace with maufacturig ad safety stadards that form the basis for stadards i may coutries. IEC stadards are drafted by experts from a miimum of five coutries, ad are iteratively drafted ad reviewed. The prevalet set of stadards icludes: Techical Committee 65 WG4, for EMC of idustrial process cotrol equipmet. This workig group has produced ad cotiues to update a family of documets that addresses surge immuity, fast trasiets, ad ESDs (IEC ). Techical Committee 77, for EMC. Withi the broad scope of all possible disturbaces to EMC, this committee develops documets related to coducted disturbaces. These documets are geeric descriptios ad classificatios of the eviromet, leadig to the specificatio of immuity tests i geeral. Detailed test specificatios for equipmet are left to product committees. IEC addresses surge protective devices coected to low-voltage power distributio systems. This is applicable to devices for surge protectio agaist idirect ad direct effects of lightig or other trasiet overvoltages. These devices are packaged to be coected to 50/60 Hz AC ad DC power circuits, ad equipmet rated up to 1000V RMS or 1500VDC Performace characteristics, stadard methods for testig, ad ratigs are established for these devices that cotai at least oe oliear compoet that is iteded to limit surge voltages ad divert surge currets. IEC Editio 2.0 (03/2005) defies the characteristics of ad tests for SPD coected to low voltage distributio systems. The test is similar i may ways to UL s 1449 third editio test; however, there are some key differeces worth otig. The followig compares the two test stadards ad idetifies the stadard with the best approach: ANSI/UL 1449 Third Editio Versus IEC Key Differeces I Testig The followig examies a few of the key differeces betwee Uderwriters Laboratory s required test for surge protective devices (SPDs); ANSI/UL 1449 Third Editio ad the Iteratioal Electrotechical Commissio (IEC) required test for SPDs, IEC Short Circuit Curret Ratig (SCCR): The capacity of curret with which the tested SPD ca withstad at the termials where coected, without breachig the eclosure i ay way. UL: Tests the full product at twice the omial voltage to see if etire product is completely offlie. The etire product (as shipped) is tested; icludig metal oxide varistors (MOVs). IEC: Test oly looks at the termials ad the physical coectios to determie if they are robust eough to hadle the fault. MOVs are replaced with a copper block ad a maufacturer s recommeded fuse is placed i-lie (exteral to the device). Best Practice: Uderwriters Laboratory There was a recet proposal ad vote withi the IEC to move towards a UL like SCCR test. However, it was met with much oppositio ad oly was approved as a volutary test. This volutary test is oly metioed i the iformative aex sectio of the IEC documet. Product Listig: A desigatio that idetifies ad differetiates whether a product has bee safety tested i its fial shipped form or as a compoet iteded for use withi aother eclosure/or device. UL: Differetiates betwee a completely listed product ad oe that is to be used withi other equipmet (recogized). Additioal testig is required for fully listed products. IEC: Does ot differetiate betwee a compoet type SPD ad a fully listed device. 12

15 Best Practice: Uderwriters Laboratory Recogizig the differeces betwee complete SPDs ad those iteded for use withi a additioal eclosure or other piece of equipmet is a critical distictio. Uder techical cosideratios, UL sets coditios of acceptability for recogized compoets; icludig wire size, eclosure size, ad spacig to ame a few. Compoets (or recogized) devices should be evaluated i their fial shipped form, or at the very least, the buyer should be made aware that the etire device has ot bee tested i its fial form. UL s desigatio allows for this. Imax: Per IEC The crest value of a curret through the SPD havig a 8/20 waveshape ad magitude accordig to the test sequece of the class II operatig duty test. UL: Does ot recogize the eed for a Imax test. IEC: A operatig duty cycle test is used to ramp up to a Imax poit (determied by the maufacturer). This is meat to fid blid poits withi the desig whe subjected to a high level impulse. This is coducted as a life expectacy or robustess test. The fuse eeds to withstad Imax, ad the test checks thermal stability of the SPD (after each duty cycle impulse brigig the SPD up to its maximum cotiuous operatig voltage MCOV) ad its physical coditio. Best Practice: IEC Tryig to determie the I maximum poit of a SPD is appropriate cosiderig the purpose of the device is to operate withi a (potetially) high surge eviromet. Products are specified ad marketed with a Imax ratig. Oe area of improvemet is to determie the level of degradatio as a meas of determiig the status of the iteral compoets. The curret requiremets offer o pre/post strike to check. Surge test data should be required i lieu of the IEC duty cycle test. I omial: The crest value of the curret through the SPD havig a curret waveshape of 8/20. UL: I omial test is similar to the IEC s, however, the I omial results do ot lik to a Up value (a value used iteratioally for electrical coordiatio). Istead, UL uses I omial to determie a product s Voltage Protectio Ratig (VPR). Levels are limited to a maximum of 20 ka. The SPD remais fuctioal after 15 surges. IEC: Does ot limit I omial testig to 20kA, however, the maufacturer s selected I level is used to get a Up value, a value cosidered to be the protective performace of the SPD. This value is used for electrical coordiatio (ratigs of buildig wire, equipmet). Therefore the goal of the maufacturer is to try to attai the highest I omial level with the lowest Up results. May maufactures opt to oly test as high as 20 ka so they will appear to have a low Up. Best Practice: Both versios have some positives ad some egatives; UL s approach allows for a greater degree of compariso betwee products, however, the SPD category type ad I omial level eed to be cosidered as part of the compariso. The IEC recogizes levels beyod 20 ka, which is i lie with UL 96A-2007, Surge Protective Devices (SPDs) rated 20 ka or more omial discharge curret (I), however, higher test levels should be examied with cascaded devices, especially at the service etrace as a way of simulatig a real world istallatio (ad IEEE Emerald Book recommedatio). Class versus category UL: UL Type desigatio is a locatio desigator with a differece to the way I omial is tested (for device which provides SCCR eeds to be icluded ad survive whe doig I omial testig). IEC: Desigates certai tests as a class I, II, or III. Class desigatio betwee I ad II has to do with the impulse applied Class I; a I imp test (10x350) ad a class II 8 x 20 μs. Best Practice: The IEC desigates certai tests as a class I, II, or III ad ca be cofused with UL s Type I, II, III, or IV desigatios. There is some validity to both idetifyig the product s approved istallatio locatio (UL) ad applyig a more robust impulse/waveform to those products that will be istalled i harsher locatios (IEC). Waveforms: A graph of a impulse wave that shows its shape ad chages i amplitude with time. UL: Recogizes the 8 x 20 μs waveform. IEC: The IEC icorporates 2 waveforms ito their test, the 8 x 20 μs which is used for class II testig to represet surges iduced oto power lies. Ad the 10 x 350 μs waveform which is used for class I testig that represets partial or direct lightig currets (due to buildig or power lie strikes). The IEC also uses other rigwave type waveforms for poit of use (class III) tests. Best Practice: IEC May variables affect the waveform/ eergy a SPD is likely to experiece. Kowledge of the SPD s performace uder differet scearios is advatageous (close strike, ear strike, distat evet, iterally geerated oise, etc). The IEEE ackowledges various wave forms. 13

16 Surge Protectio Devices Types Of Protectio There are three key types of power quality devices: SPDs, filterig/lie coditioig uits, ad data/sigal lie devices. Each of these has a specific role to play ad delivers a certai kid of protectio. These devices caot create or destroy eergy they maage it. For example, they ca divert high-eergy impulses from sesitive equipmet or dissipate them i the form of heat. AC Power Protectio A Quick Overview Of Protective Devices Withi the three types of protectio described above, there are may devices desiged for specific applicatios. Oe-Port Parallel-Coected Devices Desiged to limit high-voltage spikes to a level acceptable to most electroic equipmet. These are cosidered the first lie of defese, usig compoets placed i parallel with the lie. These devices are typically istalled at service etraces, larger distributio paels, brach pael boards, ad motor cotrol ceters. Surge Protective Device (SPD) SPDs are parallel-coected, o-liear protective devices for limitig surge voltages o equipmet by dischargig, bypassig, or divertig surge curret. They prevet cotiued flow of follow curret ad ca repeat these fuctios as specified. Domestically, the term SPD is used to describe both Surge Arresters ad Trasiet Voltage Surge Suppressors (TVSS). However, iteratioally, the term SPD is syoymous with the IEC defiitio that describes a surge compoet, ot a stad-aloe device. This compoet has o short-circuit curret ratig so it requires additioal fusig ad must be mouted iside a eclosure. Itegral SPD Issues Today, all the major electrical pael maufacturers offer some form of surge protectio, itegrated directly withi their power distributio or brach paels. Product performace, ease of istallatio, ad less wall space are some of the advatages that have bee touted over exterally mouted surge devices. While there may be some credibility to these claims, the ed user should also be aware of the risks ivolved with itegratig SPDs directly ito the power distributio equipmet. The first risk is the failure of the SPD withi the distributio equipmet. Whe SPDs fail ad the iteral MOVs reach a ed-of-life coditio, they ca create a sigificat amout of power which is dissipated i the form of heat. This heat ca be so itese that it ca cause sigificat collateral damage to the distributio equipmet. Additioally, whe that failed SPD eeds to be repaired i the field, the service techicia has two optios: remove all power from the pael; or remove oly the power feedig the SPD, leavig the rest of the pael eergized. The first optio, albeit the safest, may ot be feasible if the coected loads caot be shut off due to their criticality. The, cosiderable measures eed to be take to work i a live pael. Special gear must be wor ad tools used to protect the techicia from shock, electrical faults ad potetial arc flash. Performace is aother major area of cocer whe itegratig a SPD. Eve though performace is touted as a advatage over exterally mouted SPDs, i reality it may be far worse. For safety reasos, UL dictates the locatio of the SPD withi the gear. This ca result i the device beig mouted a log distace away from the coectio poits. The eutral bus bar for example may be as far as four feet away from the istalled SPD. This would cause the performace to be cosiderably worse tha a optimally placed, exterally mouted SPD. 14

17 Should You Cosider A Hybrid Desig? Hybrid surge protectio devices combie at least two types of surge compoets typically MOVs ad SADs. A effective hybrid desig limits the amout of surge curret through the SAD module to a acceptable level ad diverts the remaiig surge curret through the MOV module sharig the surge. Whe properly desiged, a hybrid SPD will outperform a SPD that uses oly MOVs. However, a effective hybrid SPD requires sigificat egieerig. Some of the pitfalls of a hybrid approach iclude: Desigs with all compoets o-lie at all times ca result i compoet failure durig surge or overvoltage evets. Some compoets may ot be appropriate for the applicatio of the ed uit. Some maufacturers may claim a capacitor costitutes a hybrid desig, but this may ot be the case. The key to a successful hybrid desig is to maximize each idividual compoet s stregths ad trasitio away from the weakesses. a effective hybrid SPD requires sigificat egieerig 15

18 Surge Protectio Devices (Cotiued) Two-Port (Series-Coected) Devices Filterig/lie coditioig uits are desiged to provide clea AC power by helpig to elimiate or dramatically reduce high-voltage trasiets ad low-voltage electrical lie oise that degrade microprocessor-based equipmet. They are geerally applied i frot of or i series with critical load or idustrial equipmet, such as PLCs ad motio cotrol systems. Active Trackig Filter (ATF) Active Trackig Filters offer a comprehesive level of protectio by providig clea AC power for highly sesitive equipmet. Composed of series iductors, shutabsorbig compoets, ad fast-reactig surge protective compoets, these hybrid devices elimiate low-level oise as well as protect agaist destructive high-eergy evets. Ideal applicatios iclude microprocessor-based equipmet such as programmable logic cotrollers, motio cotrol equipmet, broadcast trasmitters, ad computers. Harmoic Filter A harmoic filter is also a series-coected filter, but is desiged to atteuate frequecies that are a multiple of the fudametal 60 Hz frequecy, such as the 5th, 7th, ad 9th harmoic. Voltage Regulator Voltage regulators cotrol the output voltage, elimiatig voltage sags ad swells i the iput voltage that lasts from 15 millisecods to oe-half secod. They are typically iexpesive, feedback-cotrolled trasformers. Lie Coditioer A lie coditioer cotais multiple protectio devices i oe package to provide, for example, electrical oise isolatio ad voltage regulatio. Uiterruptible Power Supply (UPS) No-mechaical (static) uiterruptible power supplies provide protectio agaist all power disturbaces. A o-lie or true UPS coverts a utility s AC power to DC ad uses this to charge a battery ad to power a iverter that delivers power to the critical load. A off-lie UPS, called a stadby power supply (SPS), supplies the utility power directly to the critical load ad trasfers the load to a battery-powered iverter to deliver power durig outages. What is the differece betwee series coected filters ad parallel coected SPDs? Parallel devices protect equipmet from high-eergy trasiet diversio ad impulse clampig from iterally ad exterally geerated trasiets. These SPDs provide protectio from spikes by limitig let-through voltage that could destroy dowstream equipmet. Series filter techology protects from low-voltage oise caused by everyday evets, such as turig o appliaces or motors, which cause log-term degradatio of equipmet. Filter products are typically SPDs combied with iductors, capacitors, ad resistors. Parallel coected ad series coected Active Trackig Filters (ATF), both are effective power quality devices. This illustratio shows coectio diagrams for both types of systems. The parallel coected device is tapped off the load side of a service pael. Typically, a dedicated circuit breaker i the service or brach pael is used as the meas of coectio. O the other had, the series coected filter, also wired to the load side of the service pael, is directly i lie with the protected equipmet. øs N G øs N G Parallel Coected SPD Service Pael SPD Series Coected Filter Service Pael Active Trackig Filter Protector } To Pael or Loads Protector } To Pael or Loads Parallel SPDs protect agaist high-eergy trasiets by limitig or clampig the surge voltage ad divertig trasiet surge currets away from the load. The techologies most commoly used are gas discharge tubes (GDT), silico avalache diodes (SADs) ad metal oxide varistors (MOVs). SPDs are voltage-depedet oly ad are sized based o the surge curret ratig o the device. O the other had, series coected Active Trackig Filters use a low-pass circuit to protect dowstream equipmet from high-frequecy electrical lie oise. ATFs are load depedet, which meas that the series elemet is sized to hadle the maximum curret draw of the load. Iductors, together with the capacitors ad resistors, form a circuit capable of absorbig a large badwidth of oise. 16

19 Usig Surge Suppressio To Cotrol High-Voltage Trasiets High-voltage trasiets, such as those caused by lightig or grid switchig, are relatively rare. However, they get more attetio tha lowvoltage evets because their ability to cause catastrophic damage is so dramatic. Surge suppressors provide protectio from spikes by limitig let-through voltage that could destroy dow-stream equipmet. Applicatios: Ideally istalled at service etraces ad larger distributio paels. Usig Active Trackig Filters TM To Cotrol Low- Ad High-Voltage Trasiets Low-voltage oise is caused by everyday evets such as turig o appliaces or motors. Although less dramatic tha high-voltage trasiets, the log-term effect of these frequet disturbaces ca be just as damagig. Filterig systems, such as our Active Trackig Filters TM, provide clea AC power by elimiatig lower-voltage oise. Applicatios: Ideally istalled at specific sesitive loads or brach paels, or o idividual pieces of equipmet. Surge Suppressio Before High-voltage spikes appearig o 120V, 60 Hz sie wave. After Surge suppressio limits high-voltage spikes. It s your first lie of defese for power quality. High-Voltage Trasiets Low-Voltage Trasiets Filterig Before After Before After Lower-voltage trasiets (high-frequecy oise) appearig o 120V, 60 Hz sie wave. Active Trackig Filterig TM elimiates potetially damagig oise, providig clea ad reliable AC power. High-voltage spikes appearig o 120V, 60 Hz sie wave. Active Trackig Filterig TM virtually elimiates highvoltage trasiets. 17

20 Surge Protectio Devices (Cotiued) DC Low Voltage Surge Protectio Low voltage surge protectio devices safeguard the itegrity of data etworks, commuicatio systems, ad video lies from dagerous backdoor trasiets ad currets. A three-stage hybrid desig approach is oe method used to mitigate surges ad seak currets i order to reduce expesive equipmet dowtime. Protected Equipmet Power Lies Video Lies Data Lies Surge Protector Surge Protector Surge Protector Protected Surge Equipmet Protector DC Power Protectio Surge protectio desiged to protect the DC power goig to cameras or other sesitive equipmet geerally used i the security idustry. Video Lie Protectio Surge protectio devices desiged to protect camera, televisio or computer equipmet from harmful surges that may be iduced o to wires or cable lies. These devices may be used i the security, telecom or traffic idustry. Sigal Lie Protectio Surge protectio devices desiged to protect sigal lies from harmful surges. These devices are typically used i the telecom idustry to protect aalog ad digital phoe lies as well as itercom systems. Other applicatios may iclude security lies ad traffic sigal lies. Three-Stage Hybrid Sigature Circuit Data Lie Protectio Surge protectio devices primarily desiged to protect high-speed data trasmissio lies used for etwork commuicatio systems. Data lies typically travel throughout a facility ad sometimes eve betwee buildigs, leavig the system vulerable to both exterally ad iterally geerated trasiets. 18

21 Compoets Of A Surge Protector The surge compoets of a SPD begi to coduct oce it experieces voltages above a predesiged threshold (e.g., i the evet of a surge). The dagerous trasiet is suppressed or reduced to a level that is safe, but it s ot totally removed. Compoets may iclude: Metal Oxide Varistor (MOV) A solid-state device that becomes coductive whe the voltage across it exceeds a certai level. Whe the voltage exceeds the MOV s threshold, curret flows through the MOV. Advatages Cost Availability Usability Surge curret capability Disadvatages Eergy capability TOV susceptibility Capacitace Silico Avalache Diode (SAD) A semicoductor device that ormally acts as a ope circuit, but chages to a short circuit whe the trigger voltage exceeds a certai amout. Advatages Clampig TOV susceptibility Usability Pulse power Disadvatages Cost Availability Surge curret Gas Discharge Tubes (GDT) A voltage switchig device that has coductace properties that chage very rapidly from ope-circuit to quasi-short circuit whe breakdow occurs ad arc voltage occurs. Advatages Surge curret, TOV Pulse power Low capacitace Disadvatages Clampig Usability Cost Follow curret Fu se A curret limitig device, used i a electric circuit, cotaiig a coductor that melts uder heat produced by a excess curret, thereby opeig the circuit. PTC (Positive Temperature Coefficiet) Thermally sesitive resistors maufactured from semicoductor material. As the temperature approaches a predetermied value, the resistace of the part begis to rise rapidly, ad evetually levels off. Thermal expasio of the material reduces the curret to a safer level. Comparisos Fuse Vs. PTC Both provide a meas of discoect from high curret. PTC Fuse 1/2 Amp Duratioal Curret Number of Test Occurreces Before Failure PTC = Positive Temperature Coefficiet Thermistor 19

22 Selectig The Right Power Quality Device Start With The Big Questios Whe it comes time to choose the right power quality device, there are several issues to cosider. Your specificatio should focus o the essetial performace, istallatio, ad safety requiremets. As you begi, be sure to look at the big picture. What are you protectig ad how valuable is it to your busiess? Cosider the value of your equipmet ad your data. Dirty power ca destroy or corrupt data so that it becomes ureliable, ad it ca cause sigificat equipmet damage. Review the equipmet to be protected, the cost of repair or replacemet, loss of productivity, cost of aoyed customers ad loss of busiess, ad icoveiece to get the equipmet repaired or replaced. What level of protectio do you eed? The more protectio you eed, the greater the cost will be but keep i mid that the cost of ot protectig your power supply could be much greater still! What is the cost of dowtime? 40% of compaies take a day or loger to brig records back o-lie. 1 7% of compaies take loger tha a week to brig records back o-lie. 1 38% of large busiesses estimate that oe full busiess day of dowtime would result i at least $500,000 of lost reveue Iformatio Week Research Busiess Cotiuity Survey. 2. Emerso Busiess-Cotiuity Survey Impact of Dowtime. Where should you istall surge protectio withi your facility? Sice every facility is differet, there is o cut-ad-dried method of decidig where a SPD should be istalled withi your power system. Surge protectio eeds for a small busiess differ from that of larger oes. For itercoected electroic loads (e.g. via data cablig), trasiet surge suppressio should also be applied to the itercoectig wirig (data cables). The oe-lie diagrams below show how SPDs of differet sizes may be placed i key locatios throughout a busiess or residece. SPD1 represets protectio placed at the icomig service etrace of a buildig, which is commo practice. SPD2 ad SPD3 may represet protectio placed at paels that feed sesitive equipmet, where SPD4 is a direct plug-i surge protectio that could protect a computer or home theater. SPD-2 Distributio Pael Service Etrace Distributio Pael Istallatio Cosideratios Distributio Pael Brach Pael Brach Outlet Typical istallatio of surge protectio products. SPD-1 SPD-2 SPD-3 SPD-4 Parallel Coected SPDs SPDs do ot coduct a large amout of curret i their ormal state so they are idepedet of the circuits ampacity. NEC requires coductors to be either #14 copper or #12 alumium. SPDs are voltage-sesitive devices. Close attetio must be paid to the omial operatig voltage of the pael coected to avoid permaet damage to the SPD. Surge Protective Devi For optimum trasiet surge protectio, coordiated surge suppressio should be applied at the: Service etrace ad all other electrical coectios to the buildig (e.g. phoe, CATV). Typical Parallel Coectios Neutral Phases Groud Kow surge-geeratig loads withi the buildig (e.g., large motors, arc welders, switched capacitors). Sesitive electroic loads (e.g. computers, electroic appliaces, solid state motor drives). To Protected Loads Neutral Phase(s) Trasiet Groud Liebert Surge Protective Device Protected Pael Wire Should Be Less Tha 5 Feet Ad Straight As Possible Safety Groud Typical Series Coectios 20 Groud Phases Neutral

23 Performace of the SPD higes o the legth of the coductors used to coect the SPD to the protected pael. Geeral rule is to keep coductors less tha 5 feet i legth. What makes a high quality surge protectio device? Compoet level fusig MOV matchig Log life cycle Warraty All mode Modularity Compoet level moitorig Active Trackig Filters TM Pay attetio to the total curret draw for all loads, sice overloadig the uit ca permaetly damage the device. Essetial Criteria ATF Whe selectig a Active Trackig Filter TM, it is importat to kow the rated voltage, curret ad coectio type of the protected load. Low-Voltage SPDs SPDs recommed the groud be short ad straight (#10 guage is recommeded). Each SPD requires its ow groud. Do ot daisy chai. Make sure i-lie devices are ot wired backwards i the circuit, to avoid premature failure. Wire the SPD to the closest AC power groud. Whe selectig a low voltage SPD, it is importat to kow the rated operatig voltage, cotiuous curret, coectio type ad data rate of the protected load. Be sure to istall the uit at its omial operatig Surge Protective Devices voltage to avoid permaet damage to the device. Typical Parallel Coectios If the uit has exposed termial blocks, they must be istalled iside a eclosure ad located where it will ot come ito cotact with termials durig maiteace or servicig. Groud Phases Neutral Do ot use extesio cords or power strips. Route data cables as far away as possible from power cords. If iput ad output groud termials are provided, they must be coected for proper operatio. This groudig Neutral is required for both safety ad optimal equipmet Liebert Surge Phase(s) performace. Icorrect groudig ca reduce Protective or impede the operatio of the uit. Trasiet Groud Device To Protected Loads es Protected Filter must Pael be istalled Wire Should as Be close to Groud Safety the protected load as possible. Less Tha 5 Feet Ad Straight As Possible Typical Series Coectios Neutral Phases Groud Neutral Phase(s) Trasiet Groud Safety Groud To Protected Loads What makes a high quality surge protectio device? Compoet level fusig MOV matchig Log life cycle Warraty All mode Modularity Compoet level moitorig Protected Pael Istallatio, Operatio ad Maiteace Maual 5 Liebert SPDs SL Rev 5, 11/

24 Idustry-Specific Applicatios Who Needs To Protect Their Power? Every busiess eeds reliable, cosistet, high-quality power to esure its cotiued operatio. Proper power protectio ca: Deliver grid-to-chip protectio for critical equipmet ad processes i electroics. Keep data ceters secure. Provide peace-of-mid for commuicatios ifrastructures. Defed fire, alarm, ad security systems from dowtime ad damage. Idustries That Beefit From Power Protectio Iclude: Commercial/Idustrial Agriculture Prevet productivity loss, as well as material or stock waste from uexpected power outages. Educatio Maitai power for critical load areas, such as data ceters, emergecy lightig facilities ad storage facilities that require uiterrupted power supply. Govermet Maitai critical load areas such as lightig, commuicatio ad data ceters vital to govermet facilities. Hospitality Back up power without disruptig operatios ad lightig. Maufacturig Meet icreasig productio volumes ad time-to-market rates. Offices Esure cotiued protectio of the growig umber of electrical devices, eve durig maiteace. Retail Esure cotiued busiess operatios ad prevet perishables from goig to waste. Telecommuicatios Esure cotiuous service for applicatios, ad maitai ad moitor systems for optimal performace. Missio Critical Air Traffic Cotrol Protect critical load ceters; get efficiet power moitorig programs for seamless operatios. Data Ceter Prevet iformatio loss, esure busiesscritical cotiuity, ad stay ahead of the competitio. Healthcare Support operatios ad esure costat uptime for critical medical facilities. Telecommuicatios Esure reliable support for vital telecom ifrastructures for uiterrupted service to customers. Residetial / Light Commercial Gas ad Coveiece Stores Cotiue busiess operatios with emergecy power systems. Residetial Protect critical load areas to miimize icoveieces of uexpected power loss. Restaurat Meet miimum load requiremets ad prevet food spoilage; or cotiue operatios despite exteded power outages. Spotlight O Healthcare Healthcare is probably the best example of a idustry that absolutely eeds clea power. With icreasigly advaced techological equipmet, dirty power ca literally put people s lives at stake. Six out of 10 healthcare istitutios i the U.S. will lauch ew costructio or reovatio projects to accommodate icreasig demad, ad more tha 25% will add ew data ceters as the atio moves to icreased reliace o electroic medical records (EMRs). The rapidly icreasig eed for cosistet, high-quality power caot be overemphasized. I additio, patiets health, property ad capital ivestmets are also at risk. Trasportatio Keep vital trasportatio equipmet goig despite exteded power loss. Utilities Secure emergecy power systems for reliable power quality ad protectio. 22

25 For ultimate protectio, healthcare istitutios eed cascadig surge protectio that icludes: Type 1 SPDs istalled at SE locatios, emergecy power sources, ad exteral ATS termials. Type 2 SPDs istalled at all distributio locatios ad iteral ATS. Active Trackig Filters TM istalled upstream of key essetial equipmet. Data lies protected at trasmissio ad receivig eds. All security (cameras ad lie) ad fire-alarm paels protected. Spotlight O Telecommuicatios Telecommuicatios compaies are also extremely vulerable to power quality issues, sice their operatios begi ad ed with trasactios movig through electroic systems. Most switch providers uderstad the importace of effective surge protectio ad the associated costs of equipmet or system failure if there are gaps i that protectio. However, the challege remais to protect voltage-ad time-sesitive solid-state equipmet from voltage sags, swells, outages, ad trasiets that ca seriously affect their operatio. Ad as with so may other idustries, telecoms must also focus o headig off the threats that ature poses to their power-reliat systems. Spotlight O Fire/Alarm/Security FAS equipmet is geerally wired i a maer that ca itroduce harmful outside elemets to sesitive iside equipmet. FAS circuits typically eed to protrude from exterior facility walls. This provides a backdoor for surges ad trasiets, which are commoly overlooked util it s too late. Prevet damage to CCTV systems by istallig proper surge protectio o the video, power ad data lies ruig from the moitorig ad recordig equipmet to the exterior cameras. The power feedig the iside equipmet should also be protected. The idustry ladscape is rapidly chagig, with voice commuicatios steadily movig toward VoIP eviromets. Telcos of every size, i both public ad private etworks, ca expect to face a dual challege of supportig existig TDM etwork services ad addig similarly eriched VoIP capabilities. The average cosumer has high expectatios for the quality ad reliability of services, from phoe ad other commuicatios services to computers ad everythig i betwee. Icreasig demad for multifuctioal devices adds to the challege ad complexity. Fire ad burglar alarm systems should also have surge protective devices istalled o circuits, wires ad loops that peetrate the outside walls. The power ad telephoe lies goig to the fire alarm paels must also have surge protectio. Damage to access cotrol systems ca be preveted by placig surge protectio o trasmit lies, card reader lies, or ay other circuit that exits a buildig such as gate switches, gate lock cotrols or phoe lies. As always, the power comig to the cotrol pael should also be protected. 23

26 Idustry-Specific Applicatios (Cotiued) Spotlight O Trasportatio Spotlight O Data Ceters Sesitive trasportatio equipmet like highway lightig, traffic sigals, cotrol cabiets, cameras ad dyamic messagig sigs are all exposed to the outside elemets i oe fashio or aother, makig them susceptible to surge damage. You ca oly imagie the ripple effect that could occur if just oe of these systems wet out durig rush hour traffic. For today s commuicatios, bakig, ad fiacial sectors, the reliace of data ceters to obtai, store, retrieve, commuicate, ad utilize data is vital. Large data ceters ca be a stadaloe structure or specified rooms or floors withi a facility. Small data ceters rage from a sigle room to a stadaloe equipmet rack. The applicatio of surge protectio devices i frot of critical trasportatio equipmet ca elimiate dagerous situatios before they occur. For example, the istallatio of surge protectio directly iside light poles ca prevet highway lightig from goig out. Surge protective devices istalled iside traffic cabiets ca keep traffic lights correctly ruig. Pole-mouted cameras should have surge protectio ot oly to protect the camera but also the coected equipmet iside the cabiet. Whether the data ceter is categorized as large or small, the demad to process more data cotiues to grow. For this reaso, orgaizatios have replaced existig equipmet with ew, smaller, ad more powerful techology. However, this ewer IT equipmet is also more susceptible to power fluctuatios ad trasiet coditios. Providig adequate trasiet protectio requires that SPDs be istalled throughout the facility. The IEEE Emerald Book recommeds that SPDs be istalled at these specific areas withi the data ceter: Each service etrace locatio Each distributio level switchgear, UPS, or PDU All poit of use locatios (specific IT ad HVAC equipmet) Ay system (HVAC, fire alarm, security) that requires compoets to be located exteral to the structure of the facility SPDs perform a importat fuctio i the data ceter by reducig trasiet coditios, equipmet dowtime ad extedig IT equipmet life. Every busiess eeds reliable, cosistet, high-quality power 24

27 Typical Questios AC Power Surge Protectio Devices (SPDs) What aspects of istallatio affect a SPD s performace? The wire size ad legth of the coectig leads will affect the performace of parallel-coected trasiet voltage SPDs. Trasiets have fast-risig wavefrots, with typical rates of rise of curret of 100 amps per millisecod. The coectig wire s selfiductace is sigificat ad ca hamper the suppressio of high voltages while the wavefrot passes. The voltage drop across the coectig leads is added to the voltage across the suppressio elemets, degradig the SPD s performace by icreasig the residual voltage. What if your istallatio requires a log coectio ru? If a log coectio ru (more tha five feet) is uavoidable, you should use a low impedace cable. These cables (such as Liebert ACG Series AccuGuide ) help miimize voltage drops ad trasmit trasiets that are geerated by lightig ad switchig. They re usually made from coaxial cable, ad they miimize the iductace through a reduced coaxial aspect ratio. These cables ca deliver extremely low impedace (2-10 Ω) that you could t achieve with covetioal itercoectios. They ca keep your losses uder 4.2V/ft/kA much less tha losses with stadard coductors! What are the proper istallatio techiques? First, keep the coectio as close as possible, sice losses exceed 16V/ft/kA with stadard coductors. There are several basic cosideratios: 1. Your lead legths should be short ad as straight as possible. 2. To reduce the wirig impedace to surge currets, we recommed that the phase, eutral, ad groud coductors be twisted together ad routed i the same raceway (coduit). Be sure to avoid ay sharp beds i the coductors. 3. Coect to equipmet through a dedicated circuit breaker wherever possible. 4. Exteral moutig is the preferred method. This gives you the flexibility to mout close to the eutral lug, groud lug, ad breaker. How much surge curret capacity is recommeded for your istallatio? Surge curret capacity is the maximum surge curret that a SPD is rated to carry without excessive overheatig ad cosequet premature breakdow or combustio risk. The surge curret capacity of the SPD you select must match the curret required by the equipmet you eed to protect. This ca be affected by your equipmet s geographic locatio, its risk of exposure to trasiets, ad its value to your orgaizatio (impact of dowtime, repair costs). Is your UPS properly protected from surges? The typical UPS uses sigle-shot surge arrestor techology for iteral surge protectio, which provides miimal protectio ad high clampig levels. Surge protectio provided iside UPS uits does ot provide protectio whe the UPS is i bypass mode. Experts recommed that both the iput circuit to the UPS ad the associated bypass circuits (icludig the maual maiteace bypass circuit) be equipped with effective SPDs. Ca a surge protectio device save eergy? There are some SPD maufacturers who have claimed that surge suppressio devices ca save o electric utility bills. Surge protectio devices were desiged to protect equipmet from coditios that ormally cause compoet degradatio, ot to save eergy costs. The applicatio of MOVs, gas tubes, or other high-eergy surge suppressio compoets do ot cotribute to ay type of eergy coservatio. I additio, because these are geerally o-liear devices ad coduct very little curret, they virtually have o effect o the electrical system uder ormal coditios. The oly exceptio to this is durig a trasiet coditio that has a potetial great eough to sed the surge suppressio device ito coductio, ad this period of time is i the microsecods. Although there are claims ad affidavits of customers who have saved o their utility bills by applyig SPDs at their facilities, there have bee o studies published that supports these claims. How is self-iductace determied? The wirig s self-iductace is proportioal to its legth ad to the logarithm of its thickess. If you half the legth of coectig wires, this halves the iductace, but the thickess would have to be icreased tefold to achieve the same effect. The straded wires are more effective tha equivalet-sized solid coductors because of the ski effect o the total surface area. Big, short, straded coectig wires will give the best SPD performace. But keep i mid that short legth is much more importat tha large wire size. Why is the respose time of a SPD misleadig? NEMA s defiitio of respose time is the time required, after the iitiatio of a specific disturbace to a device or system, for a output to reach a specific value. I other words, the time it takes a surge protector, after a surge occurs, to clamp the trasiet voltage dow to a safe level. This value is ot easy to measure, so maufacturers ted to publish the respose time of the actual surge compoet, such the metal oxide varistor (MOV) or silico avalache diode (SAD), used withi the device. This is misleadig ad offers little value to the customer. 25

28 Typical Questios (Cotiued) The speed at which a surge suppressor respods ca be based i umerous criteria, such as: the type of surge compoet used, the overall desig of the device, ad the coductor legth used i istallatio. Most MOVs respod at similar rates, SADs because of their material compositio respod slightly faster tha MOVs. The way SPDs are desiged ca also affect the overall respose time of the device. For example, desigs that use solid copper bus bars may have lower overall impedace tha those that use wire coectios ad subsequetly respod faster. However, othig will affect the speed at which a SPD respods more tha the istalled lead legth from the SPD to the coected electrical pael. Therefore, if optimum performace is desired, more attetio should be paid to the istallatio of the SPD tha the published respose time. How may icomig lies should be protected? Some suppressors oly protect oe lie, Lie to Neutral. This is good, but icludig Lie to Groud ad Neutral to Groud, i additio to Lie to Neutral, will give you far better protectio. What is the operatig voltage required? Operatig voltage is the omial voltage that a circuit compoet eeds to fuctio properly uder ormal coditios, at a give poit i the system. The maximum safe operatig voltage for a system is determied by the compoet with lowest safe operatig voltage. A SPD with a operatig voltage sigificatly uder or over the requiremets of the system it protects will ot give the best protectio, ad may lead to uecessary damage. What is the steady-state curret of the system? Steady-state curret is the curret draw by the load over a exteded period of time. For example, equipmet draws steadystate curret while it is ruig. Steady-state curret should ot be measured whe a load cycles (e.g., whe a heatig elemet switches o or off) or whe the equipmet is first tured o (irush curret). You ll save time ad moey by matchig your steady-state curret requiremets to the steady-state rage of the SPD you are cosiderig this will help esure that you istall the right device, avoid uder-sized devices (which will ot adequately protect your sesitive equipmet), or pay too much for features you do t eed. What mode of protectio do you eed? There are several paths that trasiets ca take to reach equipmet. A three-phase wye system cosists of 10 modes (lie to lie x 3), (lie to eutral x 3), (lie to groud x 3) ad (eutral to groud x 1). Of course, the best protectio addresses each of these modes (L-N, L-G, N-G with L-L beig derived through the L-N wirig for a wye cofiguratio, or L-L ad L-G for a delta cofigured circuit). The circuit diagrams below illustrate how this is accomplished: 7-Mode versus 10-Mode L1 L1 Surge Module Surge Module L2 L2 L3 L-N Trasiet Surge Module Surge Module L3 N L-L Trasiet Surge Module L-G Trasiet Surge Module N G Surge Module N-G Trasiet G 26

29 As a idustry stadard, the lie to lie ratig is ot the result of a direct coectio betwee phases it s a path that follows oe phase through a MOV array to eutral, the back through aother MOV array to the other phase. The clampig level is thus icreased due to the additio of a array because of the idirect path ( i.e., phase A to eutral ad back to phase B, which puts two arrays i series). This is illustrated by the table below: 120 Volt, Three-Phase Wye (VPRs) LN LG NG LL 277 Volt, Three-Phase Wye (VPRs) LN LG NG LL Typical SPD 800V 800V 800V 1200V 1200V 1200V 1200V 1200V What types of warraties are there? Limited Warraty: Most surge protectio devices come with a limited warraty coverig product defects i materials ad workmaship for a predefied period of time. The terms of these limited warraties geerally rages from 1 to 10 years depedig o the type of product covered. A few maufacturers offer warraties up to 20 years, however 5 year warraties seem to be the most commo. No matter how log the warraty is, close attetio should be made to limitatios, items ot covered by warraty ad istructios for obtaiig a claim. Coected Equipmet Warraty: Some direct plug-i devices (strip type protectors) come with a warraty that advertises the replacemet of equipmet damaged from a surge or trasiet while coected to a properly istalled surge protector. Claims made o these types of warraties are ot easy to collect o because of the amout of paperwork required to file. O-Site Labor Warraty: Emerso offers a labor warraty o their premium products i which a factory traied customer egieer will come to the site where the SPD is istalled ad perform service. The stadard terms of this warraty is 5 years from time of sale. What are the differeces betwee ormal curret, surge curret, short-circuit curret, ad fault curret, ad how do they relate to surge protectio devices? Normal Curret: Uder ormal coditios, whe the AC power is clea ad free of trasiets, the SPD will oly cosume a small amout of power. Sometimes called idle curret, this is typically used to simply power the surge protectors moitorig circuit. Some surge protectors that have filterig capacitors will use slightly more power i the idle state. Surge Curret: Whe a SPD seses a trasiet, the surge compoets will begi to go ito coductio. This is required to divert the high-curret impulses away from the load ad evetually to groud. Surge impulses are fractios of a cycle, lastig oly microsecods i duratio. The amout curret the SPD ca safely divert is called the device s surge curret capacity. This value is geerally calculated by summig up all the surge compoets withi the device. The surge curret ratig is geerally measured i thousads of amperes (ka) ad may be published per each mode, per each phase or as a total amout for the etire device. Short-Circuit Curret: As with ay electrical load, SPDs eeds to have some type of curret-limitig compoet such as a fuse protectig it agaist iteral faults. These occurreces geerally happe whe a surge compoet fails short-circuit ad large currets flow for a exteded period of time. If left uiterrupted, the failure to the device ca be catastrophic. The amout of curret available to flow through this failed compoet is drive by the power system. SPD failures are geerally caused by the followig: SPD exceeds the maximum surge curret capacity Misapplicatio of a product for its voltage ratig Sustaied over-voltage evets Fault Curret: Sometimes fault coditios happe outside the device i the power distributio system that the SPD eeds to protect itself agaist. These faults could be caused by two or more phases comig i cotact with each other causig a phase fault or phase short. The outcome is large levels of curret flowig through the power coductors, circuit breakers, SPDs ad ay other devices coected i the fault path. Ulike fast-actig surge currets, faults ca last a quarter of a AC cycle or eve loger. 27

30 Typical Questios (Cotiued) Regardless of how ifrequetly faults may occur, it s critical that over-curret protectio is i place to miimize equipmet damage ad persoal ijury. Normal siewave 16.7 msec Fault curret Clearig time of fuse A ormal siewave followed by a fault. Over-curret protectio is used with SPDs to esure that the device is safely ad promptly removed from the electrical distributio system. Some SPD maufacturers icorporate curret limitig fuses directly withi their device, while others require a exteral fuse block or circuit breaker to discoect from the system. Either way, care should be take to cofirm these importat factors: Proper coordiatio of the SPD s fault ratig with that of the coected distributio pael. Testig to determie how the iteral or exteral fuses affects the overall performace of the SPD. Compliace with all applicable UL ad NEC requiremets cocerig the fault curret ratig. Properly coordiated over-curret protectio allows the SPD to hadle the published surge curret ratig without takig itself off-lie, as well as remove itself from the distributio system i the evet of a iteral failure or fault coditio. While oftetimes cofusig, the selectio of a surge protective device must iclude a basic uderstadig of the differeces betwee ormal curret, surge curret ad fault curret. Also essetial to the selectio process is kowledge about the applicatio of a SPD, the iteded istallatio eviromet ad the device s operatig characteristics. Uderstadig these iformatioal buildig blocks will help esure a well-desiged protectio system. Referece: 1. Nemasurge.com Natioal Electrical Maufacturers Associatio. What is Surge? Jauary 21,2011. < Low Voltage Protectio Do you eed low-voltage surge protectio? Low-voltage lies are typically 300 V or less, DC curret, ad applied to ay applicatio where data/ sigal is trasmitted ad/or received. Examples iclude trasmitters ad sesors, commuicatio systems, telecommuicatios, ad more. This equipmet is vulerable to trasiets ad oise, it s highly susceptible to surges, ad commoly overlooked. Low-voltage lies ca be a direct pathway of destructio, degradatio, ad disruptio for sesitive semicoductor circuits. This directly affects your PCs, electroic commuicatio, ad data. You defiitely eed to cosider SPDs to protect your low-voltage lies. What termiatio type do you eed? Termiatio types are the cable coectios betwee compoets or betwee a SPD ad the system it protects. The idividual devices must be compatible with each other. Select a surge protectio product that ca accommodate the required type of coector. What happes if the SPD is plugged i backwards? You will experiece premature protector failure ad possible damage to your equipmet. Where do you coect the groud wire? To the power groud (gree wire groud) of the protected equipmet. Does the groud wire legth make ay differece? Yes the shorter the better. Ideally, keep the groud wire less tha oe foot. If you ca t keep the groud wire less tha oe foot, the the data or sigal pair may have to be rerouted to a locatio where SPD suppressor is located ear the AC power outlet. What about a pael that has o AC power supplied to it? Power is supplied dow the sigal coductors. How do you groud the SPDs? Bod to the closest buildig approved groud poit. Also provide surge protectio betwee sigal coductors ad the groud coductor. Ca you ru groud wires iside metal coduits? Yes, but oly if the groud wire is boded to the coduit at each ed. 28

31 The Emerso Advatage Put the Power Of Emerso To Work For You Whe you choose Emerso Network Power Surge Protectio as your surge protectio parter, you ll beefit from the deep experiece, the broad rage of products ad the uparalleled service of Emerso. Emerso The Global Techology Leader Emerso Network Power (ENP) is a busiess uit of Emerso, a diversified global maufacturig ad techology compay with a wide rage of products ad services i process maagemet, climate techologies, storage solutios, professioal tools, appliace solutios, motor techologies, ad idustrial automatio. Widely recogized for its egieerig capabilities ad maagemet excellece, Emerso has over 125,000 employees ad 250 maufacturig locatios worldwide. With maufacturig ad/or sales presece i over 150 coutries, Emerso was raked umber 2 i FORTUNE s 2009 World s Most Admired Compaies i the electroics idustry. Emerso Network Power: Eablig Busiess-Critical Cotiuity For early a cetury, ENP has bee protectig power ad combatig dirty power. Our experiece uiquely positios us i today s rapidly chagig eviromet. We re costatly adaptig ad ehacig our products to meet the evolvig challeges of a icreasigly microprocessor based world. By takig a itegrated approach to protectio, we look at your etire facility from grid to chip. Our iovative products are ready to protect everythig from your iboud power, power systems, ad coectivity all the way dow to your data/sigal commuicatios. Our research ad developmet efforts help us stay ahead of the curve as idustries evolve ad expad. We hold more tha 750 active patets, ad we re costatly workig to create ew solutios to meet tomorrow s challeges. Above ad Beyod Today s Stadards ENP s products comply with idustry stadards from UL to NEC. I may cases, our products performace far exceeds these stadards. Although regulatios ad stadards frequetly chage, you ca be cofidet that we re proactively workig to meet ew stadards eve as they are beig developed. Superior Service Ad Support ENP delivers exceptioal service ad support. We offer acclaimed, bechmark-quality service: Nearly 200 global locatios Over 2,000 fully certified, highly traied ad experieced field egieers 550+ techical support/respose team members More tha 3,000 global service team members We support customers aroud the globe with o-lie, telephoe, ad o-site service. Eablig Busiess-Critical Cotiuity 29

32 The Emerso Advatage (Cotiued) Emerso Network Power Surge Protectio: Surge Specialists Emerso Network Power Surge Protectio (ENPSP), oe of Emerso Network Powers 12 Ceters of Expertise, has bee a power quality compay for more tha 35 years. It offers a broad rage of power lie filters ad state-of-theart surge suppressio equipmet. Markets from broadcast; idustrial; telecommuicatios; residetial; traffic; trasportatio; ad fire, alarm ad security areas rely o us. Our solutios are easy to istall, cost-effective, ad essetial for safeguardig sesitive data ad equipmet. ENPSP is the source for the Edco, Islatrol, Liebert, ad PowerSure products. These brads are leaders i protectig power quality ad cotiuity all with the goal of helpig your busiess succeed. The Brad You Ca Cout O ENP is committed to Busiess-Critical Cotiuity the promise that our customers techology ifrastructure ad products will always be available ad reliable. We take care of the techology that supports your busiess so you ca cocetrate o what you do best ad achieve power peace of mid. Our depedable solutios are backed by service that s equally outstadig. Customers such as Alcatel, Lucet, AT&T, Dell, Ericsso, HP, IBM, Motorola, Nokia, Chia Mobile, Chia Netcom, Huawei, ad others all trust their power to ENP. The Cost/Value Cotiuum While cost cotaimet is critical i today s ecoomy, you ca t cut corers whe it comes to power protectio. ENP builds quality, performace, ad durability ito all of our products. We price them fairly ad kow that customers uderstad their true value. Our iovatio, craftsmaship, service, ad quality deliver peace of mid ad that s priceless. State-of-the-art R & D test lab. Surge Protectio Headquarters, Bighamto, NY. 30

33 Glossary Of Terms These are some of the commo terms you ll hear whe researchig surge protectio. Alteratig Curret (AC) Flow or movemet of electrical charge that periodically reverses directio. America Natioal Stadards Istitute (ANSI) Leadig stadards-settig orgaizatio for a wide rage of products ad applicatios. Atteuatio The reductio of a sigal or electrical surge from oe poit to aother. Wire resistace, surge protective devices (SPDs), high voltage arresters, ad power coditioers atteuate surges to varyig degrees. Bodig Complete ad permaet electrical itercoectio betwee two or more poits that reduces ay differece i voltage. Capacitor A discrete electrical device which has two electrodes ad a iterveig isulator, which is called the dielectric. Clampig Voltage The peak voltage that SPDs allow ito a electric circuit based o a specific test waveform. Direct Curret (DC) Uidirectioal flow of electric charge, produced by batteries, thermocouples, solar cells, etc. Electroic Rust Trasiet damage that gradually eats away at the circuit traces that allow electricity to flow betwee electroic compoets. Fuse A protective device, used i a electric circuit, cotaiig a coductor that melts uder heat produced by a excess curret, thereby opeig the circuit Gas Discharge Tube (GDT) Whe electrical breakdow occurs, as the result of a surge, a GDT trasforms from a ope-circuit to a quasi-closed circuit. As log as the compoet s ratigs have ot bee compromised it will retur back to its ormal state oce the system stabilizes. Harmoic Distortio Excessive harmoic cotet that distorts the ormal siusoidal waveform is harmoic distortio. This ca cause overheatig of circuit elemets ad might appear to a device as data-corruptig oise. Istitute of Electrical ad Electroics Egieers (IEEE) Noprofit stadards-settig orgaizatio that has developed a wealth of stadards for a broad rage of idustries ad applicatios, icludig the surge protectio eviromet. Maximum Cotiuous Operatig Voltage (MCOV) The maximum desigated root-mea-square (RMS) value of power-frequecy voltage that may be cotiuously applied betwee the termials of the arrester. Maximum Surge Curret Ratig The maximum 8/20 ms sigle impulse the SPD is capable of survivig without performace degradatio. Measured limitig voltage The maximum magitude of voltage that appears across the termials of a SPD durig the applicatio of a impulse of specified waveshape ad amplitude. Metal Oxide Varistor (MOV) A o-liear, voltagesesitive device that becomes coductive as the voltage betwee coected coductors icreases. Modes of Protectio Stated i ka (e.g., 100kA per mode = 200kA or 300kA per phase); per phase ratig by summig two or more modes. Natioal Electric Code (NDC) Guidelies for electrical safety developed by the Natioal Fire Protectio Associatio (NFPA). Over-voltage A icrease i the ormal voltage level, lastig for secods or miutes, that exceeds the readig of a device or compoet. The term ca also apply to trasiets ad surges. Whe applied to a log-duratio variatio, it refers to overvoltage with a value of at least 10% above the omial voltage for a period of time greater tha oe miute. Positive Temperature Coefficiet (PTC) Thermally sesitive resistors maufactured from semicoductor material. As the temperature approaches a predetermied value, the resistace of the part begis to rise rapidly, ad evetually levels off. Thermal expasio of the material reduces the curret to a safer level. Impedace Measured i ohms, impedace is the total oppositio to curret flow i a circuit where alteratig curret is flowig. This icludes iductive reactace, capacitive reactace, ad resistace. 31

34 Glossary Of Terms (Cotiued) Pulse Life The umber of surges of specified voltage, curret amplitudes, ad waveshapes that may be applied to a device without causig degradatio beyod the specified limits. The pulse life applies to a device coected to a AC lie of specified characteristics ad for pulses sufficietly spaced i time to preclude the effects of cumulative heatig. Short Circuit Curret Ratig (SCCR) The capacity of curret that the tested SPD ca withstad at the termials where it s coected, without breachig the eclosure i ay way. Silico Avalache Diode (SAD) A diode made from silico that is desiged to break dow ad coduct at a specified reverse bias voltage area, breakdow occurs across the etire P-N juctio, voltage drop is essetially costat ad idepedet of curret. Trasiet A electrical evet of a o-repetitive ature. While the term is sometimes iterchageably used with impulse, it relates more to the itermittet occurrece of surge. It s a short duratio, fast-rise-time voltage caused by lightig, large motor startig, utility switchig operatios, ad other appliace switchig. Uder-voltage A decrease i the ormal voltage level, also called a sag, dig, or browout. Uderwriters Laboratories (UL) Not-for-profit testig etity that closely works with stadards-settig orgaizatios to esure product safety ad quality. Spike Also called a impulse, switchig surge, or lightig surge, this refers to a voltage icrease of very short duratio (microsecod to millisecod). Spikes may be caused by lightig, switchig of heavy loads, ad/or short circuits or power system faults. Suppressed Voltage Ratig (SVR) The discreet ratig per UL 1449 stadard, sigifyig the rouded up average clampig voltage of a SPD whe subjected to the measured limited voltage test. Surge Protective Device (SPD) The geeric term used to cover both surge arresters ad trasiet voltage surge suppressors (TVSS) devices. A SPD is a o-liear protective device for limitig surge voltages o equipmet by dischargig, bypassig, or divertig surge curret. It prevets cotiued flow of follow curret ad is capable of repeatig these fuctios as specified. SPDs ca be coected i series or i parallel with the load they are protectig. Rated Temporary Overvoltage (TOV) Withstad Level Combiatio of magitude ad duratio of temporary overvoltage that the SPD ca withstad without chages i characteristics or fuctioality. 32

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36 Headquarters Surge Protectio 100 Emerso Parkway Bighamto, NY T: T: F: E: Emerso Network Power. The global leader i eablig Busiess-Critical Cotiuity TM. EmersoNetworkPower.com/surge AC Power Coectivity Embedded Computig Embedded Power Outside Plat Power Switchig & Cotrols Racks ad Itegrated Cabiets Services DC Power Ifrastructure Maagemet & Moitorig Precisio Coolig Surge Protectio Busiess-Critical Cotiuity, Emerso Network Power ad the Emerso Network Power logo are trademarks ad service marks of Emerso Electric Co Emerso Electric Co. While every precautio has bee take to esure accuracy ad completeess i this literature, Emerso Network Power assumes o resposibility, ad disclaims all liability for damages resultig from use of this iformatio or for ay errors or omissios. SL /11 Prited i USA

37 Headquarters Surge Protectio 100 Emerso Parkway Bighamto, NY T: T: F: E: Emerso Network Power. The global leader i eablig Busiess-Critical Cotiuity TM. EmersoNetworkPower.com/surge AC Power Coectivity Embedded Computig Embedded Power Outside Plat Power Switchig & Cotrols Racks ad Itegrated Cabiets Services DC Power Ifrastructure Maagemet & Moitorig Precisio Coolig Surge Protectio Busiess-Critical Cotiuity, Emerso Network Power ad the Emerso Network Power logo are trademarks ad service marks of Emerso Electric Co Emerso Electric Co. While every precautio has bee take to esure accuracy ad completeess i this literature, Emerso Network Power assumes o resposibility, ad disclaims all liability for damages resultig from use of this iformatio or for ay errors or omissios. SL /11 Prited i USA