How do I select a proper Prosurge SPD for my application?

Though we try our best to offer an extensive, thorough product presentation on our website, catalogs and other documents, we believe the best way for model selecting is to consult with us with your requirement and then our professional will recommend a suitable model.

What are ANSI/UL 1449 Third Edition Versus IEC 61643-1 – Key Differences In Testing

The following examines a few of the key differences between Underwriters Laboratory’s required test for surge protective devices (SPDs); ANSI/UL 1449 Third Edition and the International Electrotechnical Commission (IEC) required test for SPDs, IEC 61643-1. Short Circuit Current Rating (SCCR): The capacity of current with which the tested SPD can withstand at the terminals where connected, without breaching the enclosure in any way. UL: Tests the full product at twice the nominal voltage to see if entire product is completely offline. The entire product (as shipped) is tested; including metal oxide varistors (MOVs). IEC: Test only looks at the terminals and the physical connections to determine if they are robust enough to handle the fault. MOVs are replaced with a copper block and a manufacturer’s recommended fuse is placed in-line (external to the device). Imax: Per IEC 61643-1 – The crest value of a current through the SPD having an 8/20 waveshape and magnitude according to the test sequence of the class II operating duty test. UL: Does not recognize the need for an Imax test. IEC: An operating duty cycle test is used to ramp up to an Imax point (determined by the manufacturer). This is meant to find “blind points” within the design when subjected to a high level impulse. This is conducted as a life expectancy or robustness test. The fuse needs to withstand Imax, and the test checks thermal stability of the SPD (after each duty cycle impulse bringing the SPD up to its maximum continuous operating voltage MCOV) and its physical condition。 I nominal: The crest value of the current through the SPD having a current waveshape of 8/20. UL: I nominal test is similar to the IEC’s, however, the I nominal results do not link to a Up value (a value used internationally for electrical coordination). Instead, UL uses I nominal to determine a product’s Voltage Protection Rating (VPR). Levels are limited to a maximum of 20 kA. The SPD remains functional after 15 surges. IEC: Does not limit I nominal testing to 20kA, however, the manufacturer’s selected In level is used to get a Up value, a value considered to be the protective performance of the SPD. This value is used for electrical coordination(ratings of building wire, equipment). Therefore the goal of the manufacturer is to try to attain the highest Inominal level with the lowest Up results. Many manufactures opt to only test as high as 20 kA so they will appear to have a low Up. Class versus category UL: UL Type designation is a location designator with a difference to the way I nominal is tested (for device which provides SCCR needs to be included and survive when doing I nominal testing). IEC: Designates certain tests as a class I, II, or III. Class designation between I and II has to do with the impulse applied – Class I; an I imp test (10×350) and a class II – 8 x 20 μs. The IEC designates certain tests as a class I, II, or III and can beconfused with UL’s Type I, II, III, or IV designations. There is some validity to both identifying the product’s approved installation location (UL) and applying a more robust impulse/waveform to those products that will be installed in harsher locations (IEC). Waveforms: A graph of an impulse wave that shows its shape and changes in amplitude with time. UL: Recognizes the 8 x 20 μs waveform. IEC: The IEC incorporates 2 waveforms into their test, the 8 x 20 μs which is used for class II testing to represent surges induced onto power lines. And the 10 x 350 μs waveform which is used for class I testing that represents partial or direct lightning currents (due to building or power line strikes).The IEC also uses other ring wave type waveforms for point of use (class III) tests.

How do I know which is the correct surge protection device that must be installed?

Choosing the right surge arrester(s) is a key factor to guarantee correct protection of the installation. A poorly designed Lightning & Surge protection system may lead to early ageing of the SPD and potential failure of the protective devices in the installation allowing damage to the primary systems up stream, thus defeating the rationale behind the protection being installed Prosurge does not provide a set of rules and guides to support acorrect design of the protection system according to the application. However we follow the IEC and UL lightning and surge protection standards. With this in mind we provide a cascaded system as laid down in the rules of the standard, not the rules of Prosurge. In the field of industrial applications, a standard practice is to install a cascaded protection system based on several coordinated protective devices installed at different stages (LPZ’s). The benefit of this strategy is the fact that it allows a high discharge capacity close to the installation entrance along with a low residual voltage (level of protection) at the main incomer of installation of sensitive equipment. The design of such a protective system is, amongst other factors, based on the assessment of information such as existence of a lightning rod (Lightning Protection System) and type of incoming power supply lines, secondary primary equipment and data systems. The solutions provide protection against either Transient or Permanent (TOV) overvoltages or against both of them (T+P) simultaneously. The final product choice depends on parameters such as: type of installation, type of network disconnection (operation on MCB or RCD), auto reclosing, breaking capacity, etc. Usually you can refer IEC61643- Low-voltage surge protective devices – Part 12:Surge protective devices connected to low-voltage power distribution systems -Selection and application principles

Can lightning destroy the photovoltaic system?

Photovoltaic systems are technologically highly sensitive and a direct lightning strike would definitely destroy it. There is also yet another hazard,as a lightning strike could create surge voltage near the solar power system and these surge voltages can also destroy the system. The inverter is the primary point in need of protection. Usually, inverters will integrate surge-voltage protectors into their inverters. However, since these components only discharge small voltage peaks, you should consider using surge protective devices (SPD) in individual cases.

Are joule ratings a specification used for SPD?

In the past, some manufacturers have used joule ratings in their specifications. They are not considered a good indicator for SPD performance and not recognized by any standard organizations. Prosurge doesn’t support this specification also.

Is “Response Time”a valid specification?

Response time specifications are not supported by any standards organizations overseeing Surge Protective Devices.IEEE C62.62 Standard Test Specification for SPDs specifically mentions it should not be used as a specification.

What are the different power systems in use in the US and what are the protection needs for each?

The US power distribution system is a TN-C-S system. This implies that the Neutral and Ground conductors are bonded at the service entrance of each, and every, facility or separately derived sub-system. This means that the neutral-to-ground (N-G) protection mode within a multi-mode SPD installed at the service entrance panel is basically redundant. Further from this N-G bondpoint, such as in branch distribution panels, the need for this additional mode of protection is more warranted. In addition to the N-G protection mode, some SPDs can include line-to-neutral (L-N) and line-to-line (L-L) protection. On a three phase WYE system, the need for L-L protection is questionable as balanced L-N protection also provides a measure of protection on the L-L conductors. Changes to the 2002 edition of the National Electrical Code® (NEC®) (www.nfpa.org) have precluded the use of SPDs on ungrounded delta power distribution systems. Behind this rather broad statement is the intention that SPDs should not be connected L-G as by so doing these modes of protection are creating pseudo grounds to the floating system. Modes of protection connected L-L are however acceptable.The high-leg delta system is a grounded system and as such allows for protection modes to be connected L-L and L-N or L-G.

How does installation affect the performance of SPDs?

The installation of SPDs is often poorly understood. A good SPD, incorrectly installed, can prove of little benefit in real-life surge conditions. The very high rate-of-change of current, typical of a surge transient, will develop significant volt drops on the leads connecting the SPD to the panel or equipment being protected. This can mean higher than desired voltages reaching the equipment during such a surge condition. Prosurge suggests that measures to counteract this effect include locating the SPD so as to keep interconnecting lead lengths as short as possible, twisting these leads together. Using a heavier gauge AWG cable helps to some extent but this is only a second order effect. It is also important to keep protected and unprotected circuits and leads separate to avoid cross coupling of transient energy.

What is a practical surge rating for service entrance protection?

This is a difficult question and depends on many aspects including – site exposure, regional is okeraunic levels and utility supply. A statistical study of lightning strike probability reveals that the average lightning discharge is between 30 and 40kA, while only 10% of lightning discharges exceed 100kA. Given that a strike to a transmission feeder is likely to share the total current received into anumber of distribution paths, the reality of the surge current entering a facility can be very much less than that of the lightning strike which precipitate it. The ANSI/IEEE C62.41.1-2002 standard seeks to characterize the electrical environment at different locations throughout a facility. It defines the service entrance location as between a B and C environment, meaning that surge currents up to 10kA 8/20 can be experienced in such locations. This said,SPDs located in such environments are often rated above such levels to provide a suitable operating life expectancy, 100kA/phase being typical.

What are surges transients, and temporary over-voltages, and what are their typical characteristics?

Although often used as separate terms in the surge industry, Transients and Surges are the same phenomenon. Transients and Surges can be current, voltage, or both and can have peak values in excess of 10kA or 10kV. They are typically of very short duration (usually >10 µs & <1 ms), with a waveform that has a very rapid rise to the peak and then falls off at a much slower rate. Transients and Surges can be caused by external sources such as lightning or a short circuit, or from internal sources such as Contactor switching, Variable Speed Drives, Capacitor switching, etc. Temporary over voltages (TOVs) are oscillatory phase-to-ground or phase-to-phase over voltages that can last as little as a few seconds or as long as several minutes. Sources of TOV’s include fault reclosing, load switching, ground impedance shifts,single-phase faults and ferroresonance effects to name a few. Due to their potentially high voltage and long duration, TOV’s can be very detrimental to MOV-based SPD’s. An extended TOV can cause permanent damage to an SPD and render the unit inoperable. Note that while UL 1449 (3rd Edition) ensures that the SPD will not create a safety hazard under these conditions, SPDs are not designed to protect against TOVs.

Do SPDs protect against direct lightning strikes?

A direct lighting strike is the most powerful and difficult surge to protect against. Prosurge recommend that Proper grounding and bonding of the electrical system and employing proper surge protection can protect sensitive equipment. A SPD with a higher single surge current rating will perform best against this type of event, if the unit is properly installed and the grounding system is adequate.The maximum single withstand surge current rating is defined in IEEE SPD Standard C62.62.

What is Suppressed Voltage Rating (SVR) and Voltage Protection Rating (VPR)?

SVR was part of an earlier version of UL 1449 Edition and is no longer used in the UL 1449 standard. The SVR was replaced by VPR. VPR is part of the UL 1449 3rd Edition and is the clamping performance data for SPDs. Each SPD mode is subjected to a 6kV/3kA combination surge wave and its measured clamping value is rounded up to the nearest value based on table 63.1 from UL 1449 3rd Edition.

How are SPDs related to UL 96A?

UL 96A is the standard for Lightning Protection systems. For a building to meet UL 96A is must have a Type 1 SPD with a Nominal Discharge Current rating of 20kA installed at the service entrance.

How does a Type 1 SPD compare to a Type 2 SPD?

Some key differences between Type 1 and Type 2 SPDs are: External Overcurrent Protection. Type 2 SPDs may require external overcurrent protection or it may be included within the SPD. Type 1 SPDs generally include overcurrent protection within the SPD or other means to satisfy the requirements of the standard; thus, Type 1 SPDs and Type 2 SPDs that do not require external overcurrent protection devices eliminate the potential for installing an incorrectly rated (mismatched) overcurrent protection device with the SPD. Nominal Discharge Current Ratings. Available Nominal Discharge Current (In) ratings of Type 1 SPDs are 10 kA or 20 kA; whereas, Type 2 SPDs may have 3 kA , 5 kA, 10 kA or 20 kA Nominal Discharge Current ratings. UL 1283 EMI/RFI Filtering. Some UL 1449 Listed SPDs include filter circuits that have been evaluated as a UL 1283 (Standard for Electromagnetic Interference Filters) filter. These are complimentary UL Listed as a UL 1283 filter and a UL 1449 SPD. By definition and the scope of UL 1283, UL 1283 Listed filters are evaluated for load-side applications only, not line-side applications. Consequently, UL will not complimentary list a Type 1 SPD as a UL 1283 Listed filter. However, a Type 1 SPD might include a UL 1283 filter as a Recognized Component within a Listed Type 1 SPD, which has been fully evaluated for lineside usage. Manufacturers of such products generally offer the identical SPD as a Type 2 UL 1449 Listed SPD with complimentary Listing as a UL 1283 Listed filter. Capacitors. Capacitors utilized in Type 1 SPDs may be evaluated for safety differently than in Type 2 SPDs. All capacitors in Type 1 SPD applications are evaluated to UL 810 (Standard for Capacitors). This includes filtering capacitors referenced above in UL 1283 (Standard for Electromagnetic Interference Filters) applications. Capacitors in Type 2 SPDs are evaluated to UL 1414 (Standard for Capacitors and Suppressors for Radio- and Television-Type Appliances) and/or UL 1283 (Standard for Electromagnetic Interference Filters).

What are the UL SPD Type categories and what do they mean?

Type 1 SPDs (Listed) – Permanently connected, hard-wired SPDs intended for installation between the secondary of the service transformer and the line side of the main service equipment overcurrent protective device, as well as the load side of the main service equipment (i.e. Type 1’s can be installed anywhere within the distribution system). Type 1 SPDs include watt-hour meter socket enclosure type SPDs. Being on the line side of the service disconnect where there are no overcurrent protective devices to protect an SPD, Type 1 SPDs must be listed without the use of an external overcurrent protective device. The Nominal Discharge Current Rating for Type 1 SPDs is either 10kA or 20kA. Type 2 SPDs (Listed) – Permanently connected, hard-wired SPDs intended for installation on the load side of the main service equipment overcurrent protective device. These SPDs may also be installed at the main service equipment, but must be installed on the load side of the main service overcurrent protective device. Type 2 SPDs may or may not require an overcurrent protection device per their NRTL listing. If a specific overcurrent protection is required, the SPD’s NRTL listing file and labeling/instructions are required to note the size and type of overcurrent protective device. Note: In some cases the overcurrent protective device used can impact the nominal discharge rating of the SPD. For example, the SPD may have a 10 kA nominal discharge current rating when protected by a 30 Amp circuit breaker and a 20 kA nominal discharge current rating when protected by a different but specific make and model of overcurrent protection device. The Nominal Discharge Current Rating for Type 2 SPDs is 3 kA, 5 kA, 10 kA, or 20 kA. Type 3 SPDs (Listed) – These SPDs are called, ‘Point of Utilization SPDs’, which are to be installed at a minimum conductor length of 10 meter (30 feet) from the electrical service panel unless they are evaluated at Type 2 SPDs (that is, they receive a Nominal Discharge Current Rating of 3 kA minimum). Typically, these are cord-connected surge strips, direct plug-in SPDs, or receptacle-type SPDs installed at the utilization equipment being protected (i.e. computers, copy machines, etc.). Type 1, 2, 3 Component Assembly SPDs (Component Recognized) – These SPDs are intended to be factory installed into electrical distribution equipment or end-use equipment. These are Recognized Component SPDs evaluated for use in Type 1, 2 or 3 SPD applications. Such component SPDs must pass all the same electrical safety failure tests as listed Type 1, 2 or 3 SPDs. While these SPDs are 100% compliant from a safety failure testing point of view, these Type 1, 2 and 3 component assembly SPDs have conditions of acceptability such as exposed terminals or other mechanical construction that requires them to be installed or housed within a listed assembly to provide protection from exposure to live parts or other requirements. These Type 1, 2 or 3 Recognized Component SPDs should not be confused with ANSI/UL 1449-2006 Type 4 Component Assemblies and Type 5 discrete SPD components that require additional components (possibly safety disconnectors), design and testing in order to be used as a complete surge protective device. Type 4 Component Assembly SPD (Component Recognized) –– These component assemblies consist of one or more Type 5 SPD components together with a disconnector (integral or external) or a means of complying with the limited current tests in UL 1449, Section 39.4. These are incomplete SPD assemblies, which typically are installed in listed end-use products as long as all conditions of acceptability are met. These Type 4 component assemblies are incomplete as an SPD, require further evaluation and are not permitted to be installed in the field as a stand-alone SPD. Often, these devices require additional overcurrent protection. Type 5 SPD (Component Recognized) – Discrete component surge protection devices, such as MOVs that may be mounted on a printed wiring board, connected by its leads or provided within an enclosure with mounting means and wiring terminations. These Type 5 SPD components are incomplete as an SPD, require further evaluation and are not permitted to be installed in the field as a stand-alone SPD. Type 5 SPDs are generally the components used in the design and construction of complete SPDs or other SPD assemblies.

What is the UL Short Circuit Current Rating (SCCR)?

SSCR-Short Circuit Current Rating. The suitability of an SPD for use on an AC power circuit that is capable of delivering not more than a declared rms symmetrical current at a declared voltage during a short circuit condition. SCCR is not the same as AIC (Amp Interrupting Capacity). SCCR is the amount of “available”current that the SPD can be subjected to and safely disconnect from the power source under short circuit conditions. The amount of current “interrupted” by the SPD is typically significantly less than the “available” current. UL 1449 and the National Electric Code (NEC) require the SCCR (Short Circuit Current Rating) to be marked on all SPD units. It is not a surge rating, but the maximum allowable current a SPD can interrupt in the event of failure. The NEC/UL has a requirement that the SPD be tested and labelled with a SCCR equal to, or greater than the available fault current at that point in the system.

What is important when specifying SPD?

When specifying SPD, submit a clear, concise specification detailing the required performance and design features. A minimum specification should include: • UL surge rating • Suppression rating • Short circuit rating • Peak surge current per mode (L-N, L-G, and N-G) • voltage and configuration of electrical service

What is a Surge Protective Device or Surge Arrestor (SPD)?

SPD is a device designed to limit surge energy to electrical equipment. It does this by diverting or limiting surge current. An SPD is wired in parallel to the equipment it is intended to protect. Once the surge voltage exceeds its designed rating it “begins to clamp” and starts to conduct energy directly to the electrical grounding system. An SPD has a very low resistance during this time and “shorts” the energy to ground. Once the surge is over it “opens” up, so it does not trigger upstream circuit breakers.

FAQ - Prosurge

Q: Do SPDs protect against direct lightning strikes?

A direct lighting strike is the most powerful and difficult surge to protect against. Prosurge recommend that Proper grounding and bonding of the electrical system and employing proper surge protection can protect sensitive equipment. A SPD with a higher single surge current rating will perform best against this type of event, if the unit is properly installed and the grounding system is adequate.The maximum single withstand surge current rating is defined in IEEE SPD Standard C62.62.

Hoe kies ek 'n behoorlike Prosurge SPD vir my aansoek?prosurge2017-10-31T17:34:33+08:00

Hoe kies ek 'n behoorlike Prosurge SPD vir my aansoek?

Alhoewel ons ons bes probeer om 'n omvattende, deeglike produkaanbieding op ons webwerf, katalogusse en ander dokumente aan te bied, glo ons dat die beste manier vir die keuse van die model is om met u te eis, en dan sal ons professionele 'n geskikte model aanbeveel.

Wat is ANSI / UL 1449 Derde Uitgawe versus IEC 61643-1 - Sleutelverskille in Toetsprosurge2017-10-31T17:29:56+08:00

Wat is ANSI / UL 1449 Derde Uitgawe versus IEC 61643-1 - Sleutelverskille in Toets

Die volgende ondersoek 'n paar van die belangrikste verskille tussen die onderskrywers Laboratorium se vereiste toets vir surge protection devices (SPDs); ANSI / UL 1449 Derde Uitgawe en die Internasionale Elektriese Tegniese Kommissie (OVK) het toets vir SPD's, IEC 61643-1 vereis.

Kort stroom stroomgradering (SCCR): Die kapasiteit van stroom waarmee die getoetse SPD kan bystaan by die terminale waar verbind word, sonder om die omhulsel op enige manier te breek.

UL: Toets die volle produk by twee keer die nominale spanning om te sien of die hele produk heeltemal aflyn is. Die hele produk (soos gestuur) word getoets; insluitende metaaloksiedvaristors (MOV's).

IEC: Toets net kyk na die terminale en die fisiese verbindings om te bepaal of hulle robuust genoeg is om die fout te hanteer. MOV's word vervang met 'n koperblok en 'n vervaardiger se aanbevole siklus word in die lyn geplaas (buite die toestel).

Imax: Per IEC 61643-1 - Die helmtekenwaarde van 'n stroom deur middel van die SPD met 'n 8 / 20 waveshape en grootte volgens die toetsvolgorde van die klas II operasionele diens toets.

UL: herken nie die behoefte aan 'n Imax-toets nie.

IEC: 'n Werksiklustoets word gebruik om op te stoot tot 'n Imax-punt (bepaal deur die vervaardiger). Dit is bedoel om 'blinde punte' binne die ontwerp te vind wanneer dit aan 'n hoë vlak impuls onderwerp word. Dit word as 'n lewensverwagtingstoets gedoen. Die lont moet Imax weerstaan, en die toets kontroleer die thermiese stabiliteit van die SPD (na elke dienssiklusimpuls wat die SPD op sy maksimum deurlopende werkspanning MCOV verhoog) en sy fisiese toestand。

Ek nominale: Die helmtekenwaarde van die stroom deur die SPD met 'n huidige waveshape van 8 / 20.

UL: Ek nominale toets is soortgelyk aan die IEC's, maar die nominale resultate koppel nie aan 'n opwaarde nie ('n waarde wat internasionaal gebruik word vir elektriese koördinasie). In plaas daarvan gebruik UL ek nominale om 'n produk se Voltage Protection Rating (VPR) te bepaal. Vlakke is beperk tot 'n maksimum van 20 kA. Die SPD bly funksioneel na 15-stygings.

IEC: Beperk ek nie nominale toetsing aan 20kA nie, maar die vervaardiger se gekose In-vlak word gebruik om 'n Up-waarde te kry, 'n waarde wat beskou word as die beskermende prestasie van die SPD. Hierdie waarde word gebruik vir elektriese koördinasie (graderings van boudraad, toerusting).

Daarom is die doel van die vervaardiger om te probeer om die hoogste binne-vlak te behaal met die laagste resultate. Baie vervaardigers kies om net so hoog soos 20 kA te toets, sodat hulle 'n lae hoër sal wees.

Klas teenoor kategorie

UL: UL Tipe aanwysing is 'n ligging aanwyser met 'n verskil in die manier waarop ek nominale getoets word (vir toestel wat SCCR benodig, moet ingesluit word en oorleef wanneer ek 'n nominale toets doen).

OVK: dui sekere toetse aan as klas I, II of III. Klasbenaming tussen I en II het te make met die toegepaste impuls - Klas I; 'n I imp toets (10 × 350) en 'n klas II - 8 x 20 μs.

Die OVK wys sekere toetse as 'n klas I, II of III aan en kan met UL se tipe I, II, III of IV benoem word. Daar is sekere geldigheid om beide die produk se goedgekeurde installasie-plek (UL) te identifiseer en 'n sterker impuls / golfvorm toe te pas op die produkte wat op erger plekke (IEC) geïnstalleer sal word.

Golfvorms: 'n Grafiek van 'n impulsgolf wat sy vorm toon en verander in amplitude met tyd.

UL: Herken die 8 x 20 μs golfvorm.

OVK: Die OVK bevat 2-golfvorms in hul toets, die 8 x 20 μs wat gebruik word vir klas II toetse om stygings wat op kraglyne geïnduseer word, voor te stel. En die 10 x 350 μs-golfvorm wat gebruik word vir die toets van klasse I wat gedeeltelike of direkte weerligstrome verteenwoordig (as gevolg van gebou- of kraglynaanvalle). Die OVK gebruik ook ander golfgolf tipe golfvorms vir gebruiksaanwendings (klas III) toetse.

Hoe weet ek wat is die korrekte stuwingsbeskermingsapparaat wat geïnstalleer moet word?prosurge2017-10-31T17:28:05+08:00

Hoe weet ek wat is die korrekte stuwingsbeskermingsapparaat wat geïnstalleer moet word?

Die regte oorspanningsafleider (s) is 'n belangrike faktor om die korrekte beskerming van die installasie te waarborg. 'N Swak ontwerpte Lightning & Surge-beveiligingstelsel kan lei tot die vroeë veroudering van die SPD en die moontlike mislukking van die beskermingstoestelle in die installasie, wat skade aan die primêre stelsels kan laat stroom, en sodoende die rasionaal agter die beskerming wat geïnstalleer word, kan verswak

Prosurge verskaf nie 'n stel reëls en riglyne om die korrekte ontwerp van die beskermingstelsel volgens die aansoek te ondersteun nie. Ons volg egter die OVS- en UL-weerlig- en stuwingsbeveiligingsstandaarde. Met hierdie in gedagte bied ons 'n cascaded stelsel soos neergelê in die reëls van die standaard, nie die Prosurge-reëls nie.

Op die gebied van industriële toepassings is 'n standaardpraktyk 'n kaskadebeskermingstelsel wat gebaseer is op verskeie gekoördineerde beskermende toestelle wat in verskillende stadiums geïnstalleer is. Die voordeel van hierdie strategie is die feit dat dit 'n hoë ontslagkapasiteit naby die installasie-ingang toelaat, asook 'n lae residuele spanning (vlak van beskerming) by die hoofaanval van die installering van sensitiewe toerusting.

Die ontwerp van so 'n beskermende stelsel is onder meer gebaseer op die assessering van inligting soos die bestaan van 'n weerligstrook (Weerligbeskermingsstelsel) en die tipe inkomende kragtoevoerlyne, sekondêre primêre toerusting en datastelsels.

Die oplossings bied tegelykertyd beskerming teen beide Oorgangs- of Permanente (TOV) oorvoltings of teen beide (T + P).

Die finale produkkeuse hang af van parameters soos: tipe installasie, tipe netwerkonderbreking (operasie op MCB of RCD), outomatiese herwinning, kapasiteit, ens.

Gewoonlik kan u IEC61643- Laagspanningsbeveiligingstoestelle verwys - Deel 12: Spanningsbeveiligingstoestelle gekoppel aan laespanning-kragverspreidingstelsels - Seleksie- en toepassingsbeginsels

Kan weerlig die fotovoltaïese stelsel vernietig?prosurge2017-10-31T17:26:31+08:00

Kan weerlig die fotovoltaïese stelsel vernietig?

Fotovoltaïese stelsels is tegnologies hoogs sensitief en 'n direkte weerligstaking sal dit beslis vernietig. Daar is ook nog 'n gevaar, aangesien 'n weerligstaking spanning naby die sonkragstelsel kan veroorsaak en hierdie opwaartse spannings kan ook die stelsel vernietig. Die omskakelaar is die primêre punt wat beskerming benodig. Gewoonlik sal omsetters spanningsbeskermers in hul omsetters integreer. Aangesien hierdie komponente egter slegs klein spanningspieke uitlaat, moet u in individuele gevalle oorweegbeskermingsmiddels (SPD) gebruik.

Is joule-graderings 'n spesifikasie wat vir SPD gebruik word?prosurge2017-10-31T17:25:41+08:00

Is joule-graderings 'n spesifikasie wat vir SPD gebruik word?

In die verlede het sommige vervaardigers joule-graderings in hul spesifikasies gebruik. Hulle word nie as 'n goeie aanwyser vir SPD-prestasie beskou nie en word nie deur enige standaard organisasies erken nie. Prosurge ondersteun ook nie hierdie spesifikasie nie.

Is "Response Time" 'n geldige spesifikasie?prosurge2017-10-31T17:24:47+08:00

Is "Response Time" 'n geldige spesifikasie?

Reaksie tyd spesifikasies word nie ondersteun deur enige standaarde organisasies toesig Surge Protective Devices.IEEE C62.62 Standaard Toets spesifikasie vir SPDs spesifiek noem dit moet nie gebruik word as 'n spesifikasie.

Wat is die verskillende kragstelsels in gebruik in die VSA en wat is die beskerming benodighede vir elkeen?prosurge2017-10-31T17:23:39+08:00

Wat is die verskillende kragstelsels in gebruik in die VSA en wat is die beskerming benodighede vir elkeen?

Die Amerikaanse kragverspreidingstelsel is 'n TN-CS-stelsel. Dit impliseer dat die Neutrale en Grondgeleiers by die diensingang van elke, en elke fasiliteit of afsonderlike afgeleide substelsel gebind word. Dit beteken dat die neutrale-tot-grond-beskerming (NG) -beskermingsmodus binne 'n multi-modus SPD geïnstalleer by die dienspaneel basies oorbodig is. Verdere van hierdie NG-bindingspunt, soos in takverspreidingspanele, is die behoefte aan hierdie addisionele beskermingstipe meer geregverdig. Benewens die NG-beskermingsmodus, kan sommige SPD's lyn-na-neutrale (LN) en lyn-tot-lyn-beskerming (LL) insluit. Op 'n drie-fase WYE-stelsel is die behoefte aan LL-beskerming te betwyfel aangesien gebalanseerde LN-beskerming ook 'n mate van beskerming bied op die LL-geleiers.
Veranderinge aan die 2002-uitgawe van die Nasionale Elektriese Kode® (NEC®) (www.nfpa.org) het die gebruik van SPD's op ongegronde delta-kragverspreidingstelsels uitgesluit. Agter hierdie taamlike breë stelling is die bedoeling dat SPD's nie gekoppel moet word nie. Deur dit te doen, is dit moontlik om pseudo-gronde aan die swaaistelsel te skep. Beskermingsmodusse wat met LL verband hou, is egter aanvaarbaar. Die hoëbeen-delta-stelsel is 'n gegronde stelsel en sodoende kan beskermingswyses met LL en LN of LG verbind word.

Hoe beïnvloed installasie die prestasie van SPD's?prosurge2017-10-31T17:19:51+08:00

Hoe beïnvloed installasie die prestasie van SPD's?

Die installering van SPD's word dikwels swak verstaan. 'N goeie SPD, verkeerd geïnstalleer, kan bewys van min voordeel in real-life oplewing voorwaardes. Die baie hoë tempo van verandering van die huidige, tipiese van 'n surge-oorgang, sal aansienlike volt druppels ontwikkel op die leidings wat die SPD verbind met die paneel of toerusting wat beskerm word. Dit kan hoër wees as verlangde spannings wat die toerusting tydens so 'n oplewingstoestand bereik. Prosurge suggereer dat maatreëls om hierdie effek teen te werk, insluit om die SPD te vind sodat die loodlengte so kort moontlik met mekaar verbind word, om hierdie leidings saam te draai. Deur 'n swaarder maat te gebruik, help AWG kabel tot 'n mate, maar dit is slegs 'n tweede orde effek. Dit is ook belangrik om beskermde en onbeskermde stroombane te hou en lei afsonderlik om kruiskoppeling van oorgangs energie te vermy.

Wat is 'n praktiese oplewing vir diens toegangsbeskerming?prosurge2017-10-31T17:17:34+08:00

Wat is 'n praktiese oplewing vir diens toegangsbeskerming?

Dit is 'n moeilike vraag en hang af van baie aspekte, insluitend: - blootstelling aan die werf, streeks is okeraunic vlakke en nutvoorsiening. 'N Statistiese studie van weerligwaarskynlikheid toon dat die gemiddelde weerlig ontslag tussen 30 en 40kA is, terwyl slegs 10% van weerlig ontslaan 100kA oorskry. Aangesien 'n staking na 'n transmissievoeder waarskynlik die totale stroom wat in 'n aantal verspreidingspaaie ontvang word, kan deel, kan die realiteit van die stroomstroom wat 'n fasiliteit binnegaan, baie minder wees as dié van die weerligstaking wat dit neersit.

Die ANSI / IEEE C62.41.1-2002-standaard poog om die elektriese omgewing op verskillende plekke deur 'n fasiliteit te karakteriseer. Dit definieer die diens ingangs-plek tussen 'n B en C omgewing, wat beteken dat opwaartse strome tot 10kA 8 / 20 op sulke plekke ervaar kan word. Dit gesê, SPD's in sulke omgewings word dikwels bo sulke vlakke gegradeer om 'n geskikte lewensverwagting te bied, 100kA / fase is tipies.

Wat is oorgangsgevangenes en tydelike oorspannings, en wat is hul tipiese eienskappe?prosurge2017-10-31T17:16:14+08:00

Wat is oorgangsgevangenes en tydelike oorspannings, en wat is hul tipiese eienskappe?

Alhoewel dit dikwels as afsonderlike terme in die oplewingbedryf gebruik word, is Transients en Surges dieselfde verskynsel. Transiënte en stuwings kan stroom, spanning of albei wees en kan piekwaardes van meer as 10 kA of 10 kV hê. Hulle het gewoonlik 'n baie kort duur (gewoonlik> 10 µs en <1 ms), met 'n golfvorm wat baie vinnig na die piek styg en dan teen 'n baie stadiger tempo val. Transiënte en stootstowwe kan veroorsaak word deur eksterne bronne soos weerlig of kortsluiting, of deur interne bronne soos kontakskakelaar, veranderlike snelhede, kondensatorskakeling, ens.

Tydelike oor spannings (TOV's) is ossillatoriese fase-tot-grond- of fase-tot-fase-oorspanning wat so min as 'n paar sekondes of so lank as 'n paar minute kan duur. Bronne van TOV's sluit in foutherwinning, ladingskakel, grondimpedansie verskuiwings, enkelfase foute en ferroresonance effekte om 'n paar te noem. As gevolg van hul potensiaal hoë spanning en lang duur, kan TOV's baie nadelig wees vir MOV-gebaseerde SPD's. 'N Uitgebreide TOV kan permanente skade aan 'n SPD veroorsaak en die eenheid onbruikbaar maak. Let daarop dat, terwyl UL 1449 (3rd Edition) verseker dat die SPD nie onder hierdie toestande 'n veiligheidsgevaar skep nie, is SPD's nie ontwerp om teen TOV's te beskerm nie.

Beskerm SPD's teen direkte weerligstaking?prosurge2017-10-31T17:13:42+08:00

Beskerm SPD's teen direkte weerligstaking?

'N direkte beligting staking is die mees kragtige en moeilike oplewing te beskerm teen. Prosurge beveel aan dat behoorlike aarding en binding van die elektriese stelsel en die gebruik van behoorlike overspanning beskerming sensitiewe toerusting beskerm. 'N SPD met 'n hoër enkelspanning huidige beoordeling sal die beste presteer teen hierdie tipe gebeurtenis, as die eenheid behoorlik geïnstalleer is en die aardingstelsel voldoende is. Die maksimum enkelweerstand-stroomtoets is gedefinieer in IEEE SPD Standard C62.62.

Wat is Onderdrukte Voltage Rating (SVR) en Voltage Protection Rating (VPR)?prosurge2017-10-31T17:10:31+08:00

Wat is Onderdrukte Voltage Rating (SVR) en Voltage Protection Rating (VPR)?

SVR was deel van 'n vorige weergawe van UL 1449 Edition en word nie meer in die UL 1449-standaard gebruik nie. Die SVR is vervang deur VPR.

VPR is deel van die UL 1449 3rd Edition en is die klem prestasie data vir SPDs. Elke SPD af is onderworpe aan 'n 6kV / 3kA kombinasie surge golf en die gemete klemwaarde word afgerond tot die naaste waarde gebaseer op tabel 63.1 van UL 1449 3rd Edition.

Hoe is SPD's verwant aan UL 96A?prosurge2017-10-31T17:05:54+08:00

Hoe is SPD's verwant aan UL 96A?

UL 96A is die standaard vir Lightning Protection-stelsels. Vir 'n gebou wat UL 96A moet ontmoet, moet 'n Type 1 SPD met 'n nominale afvoerstroombedrag van 20kA by die diensingang geïnstalleer word.

Hoe vergelyk 'n Type 1 SPD met 'n Type 2 SPD?prosurge2017-10-31T17:01:51+08:00

Hoe vergelyk 'n Type 1 SPD met 'n Type 2 SPD?

Enkele belangrike verskille tussen Tipe 1 en Tipe 2 SPD's is:

Eksterne oorstroombeskerming. Tipe 2 SPD's kan eksterne oorstroom vereis
beskerming of dit mag ingesluit word in die SPD. Tipe 1 SPD'e bevat gewoonlik
oorstroombeskerming binne die SPD of ander middele om aan die vereistes te voldoen
van die standaard; dus, Tik 1 SPD's en Type 2 SPD's wat nie eksterne benodig nie
oorstroombeskermings toestelle elimineer die potensiaal om 'n verkeerde installasie te installeer
gegradeerde (verkeerde) oorstroombeskermingsapparaat met die SPD.
Nominale ontslag huidige waardes. Beskikbaar Nominale Afvoerstroom (In)
Graderings van Tipe 1 SPD's is 10 kA of 20 kA; terwyl 2-SPD's van tipe 3 mag hê
kA, 5 kA, 10 kA of 20 kA Nominale afvoerstroom-graderings.
UL 1283 EMI / RFI filter. Sommige UL 1449-genoteerde SPD's sluit filterbane in
wat geëvalueer is as 'n UL 1283 (Standaard vir Elektromagnetiese Interferensie
Filters) filter. Hierdie is komplimentêre UL wat as 'n UL 1283 filter en 'n UL beskou word
1449 SPD. Per definisie en die omvang van UL 1283, UL 1283 Genoteerde filters is
evalueer slegs vir laai-kant-aansoeke, nie aanlyn-toepassings nie.
Gevolglik sal UL nie 'n Tipe 1 SPD as 'n UL 1283 Genoteer, opsioneel lys nie
filter. 'N Type 1 SPD kan egter 'n UL 1283-filter as 'n Erkenning insluit
Komponent binne 'n genoteerde tipe 1 SPD, wat ten volle vir lynlyne geëvalueer is
gebruik. Vervaardigers van sulke produkte bied gewoonlik die identiese SPD as 'n
Tik 2 UL 1449 Genoteerde SPD met komplimentêre aanbieding as 'n UL 1283 Genoteer
filter.
Kapasitors. Kapasitors wat in Tipe 1 SPD's gebruik word, kan vir veiligheid geëvalueer word
anders as in Tipe 2 SPD's. Alle kapasitors in Tipe 1 SPD toepassings is
geëvalueer aan UL 810 (Standaard vir Kapasitors). Dit sluit in filterkapasitors
hierbo verwys in UL 1283 (Standaard vir Elektromagnetiese Interferensie Filters)
aansoeke. Kapasitors in Type 2 SPD's word geëvalueer na UL 1414 (Standaard vir
Kapasitors en Onderdrukkers vir Radio- en Televisie-tipe toestelle) en / of
UL 1283 (Standaard vir Elektromagnetiese Interferensie Filters).

Wat is die UL SPD Type kategorieë en wat bedoel dit?prosurge2017-10-31T16:58:48+08:00

Wat is die UL SPD Type kategorieë en wat bedoel dit?

Tik 1 SPDs (Genoteer) - Permanent gekoppelde, hardgekoppelde SPD's bedoel vir
installasie tussen die sekondêre van die diens transformator en die lynkant van die hoof
diens toerusting oorstroom beskerming toestel, sowel as die laai kant van die hoof
Diens toerusting (dws Tipe 1's kan oral in die verspreiding geïnstalleer word
stelsel). Tipe 1 SPDs sluit in watt-uur meter-sokkel tipe SPD's. Om op die
lyn kant van die diens ontkoppel waar daar geen oorstroom beskermende toestelle is
beskerm 'n SPD, Tipe 1 SPD's moet gelys word sonder die gebruik van 'n eksterne oorstroom
beskermende toestel. Die Nominale Afvoer Huidige Prestasie vir Type 1 SPDs is ook
10kA of 20kA.

Tik 2 SPDs (Genoteer) - Permanent gekoppelde, hardgekoppelde SPD's bedoel vir
installasie aan die laai kant van die hoof-diens toerusting oorstroom beskerming toestel.
Hierdie SPD's kan ook by die hoof diens toerusting geïnstalleer word, maar moet geïnstalleer word op
die las kant van die hoof diens oorstroom beskermende toestel. Tik 2 SPD's mag of mag
benodig nie 'n oorstroombeskermingsapparaat per hul NRTL-lys nie. As 'n spesifieke
Oorstroombeskerming word benodig, die SPD se NRTL-lêer en etikettering / instruksies
moet die grootte en tipe oorstroombeskermings toestel opmerk. Nota: In sommige
gevalle waar die oorstroombeveiligingstoestel gebruik kan word, kan die nominale ontladingsgraad van
die SPD. Byvoorbeeld, die SPD kan 'n 10 kA nominale afvoerstroomgradering hê
wanneer dit beskerm word deur 'n 30 Amp-stroombreker en 'n 20 kA nominale ontladingsstroom
beoordeling wanneer beskerm deur 'n ander maar spesifieke merk en model van oorstroom
beskermings toestel. Die nominale afvoerstroombedrag vir die tipe 2 SPDs is 3 kA, 5
kA, 10 kA, of 20 kA.

Tik 3 SPDs (Genoteer) - Hierdie SPD's word genoem, 'Point of Utilization SPDs', wat na
geïnstalleer word teen 'n minimum geleier lengte van 10 meter (30 voete) van die elektriese
dienspaneel, tensy hulle geëvalueer word by Tipe 2 SPD's (dit wil sê, hulle ontvang 'n Nominale
Laai huidige stroom van 3 kA minimum). Tipies, dit is koord-gekoppelde oplewing
stroke, direkte plug-in SPD's, of houers-tipe SPD's geïnstalleer by die gebruik toerusting
beskerm word (dws rekenaars, kopieermasjiene, ens.).

Tipe 1-, 2-, 3-komponente-samestelling-SPD's (komponente herken) - Hierdie SPD's is
bedoel om fabriek geïnstalleer te word in elektriese verspreidingstoerusting of eindgebruik
toerusting. Hierdie is erkende komponent-SPD's wat vir gebruik in Tipe 1, 2 of 3 geëvalueer word.
SPD aansoeke. Sulke komponent-SPD's moet dieselfde elektriese veiligheidsversaking slaag
toetse soos gelys Tipe 1, 2 of 3 SPDs. Terwyl hierdie SPD's 100% voldoen aan 'n veiligheid
versuim toets oogpunt, hierdie tipe 1, 2 en 3 komponent vergadering SPDs het
voorwaardes van aanvaarbaarheid soos blootgestelde terminale of ander meganiese konstruksie
Dit vereis dat hulle geïnstalleer of gehuisves word binne 'n gelysde vergadering om beskerming te bied
van blootstelling aan lewende dele of ander vereistes. Hierdie tipe 1, 2 of 3 erken
Komponent SPD's moet nie verwar word met ANSI / UL 1449-2006 Type 4 komponent
Vergelykings en Tipe 5 diskrete SPD komponente wat addisionele komponente benodig
(moontlik veiligheidskonnekteerders), ontwerp en toets om as 'n volledige oplewing gebruik te word
beskermende toestel.

Tipe 4 komponent vergadering SPD (komponent herken) - Hierdie komponent
gemeentes bestaan uit een of meer Tipe 5 SPD komponente tesame met 'n ontkoppelaar
(integraal of ekstern) of 'n manier om te voldoen aan die beperkte stroomtoetse in UL 1449,
Afdeling 39.4. Hierdie is onvolledige SPD gemeentes, wat tipies geïnstalleer is in
genoteerde eindgebruiksprodukte solank as wat alle aanvaarbaarheidsvereistes nagekom word. Hierdie tipe 4
komponent vergaderings is onvolledig as 'n SPD, vereis verdere evaluering en is nie
Mag in die veld geïnstalleer word as 'n alleenstaande SPD. Dikwels benodig hierdie toestelle
bykomende oorstroombeskerming.

Tik 5 SPD (komponent herken) - Diskrete komponent oplewing beveiligings toestelle,
soos MOV's wat op 'n gedrukte bedradingsraad gemonteer kan word, gekoppel deur sy lei of
voorsien in 'n omhulsel met monteermiddele en bedradingstermings. Hierdie tipe
5 SPD komponente is onvolledig as 'n SPD, vereis verdere evaluering en is nie
Mag in die veld geïnstalleer word as 'n alleenstaande SPD. Tipe 5 SPD's is oor die algemeen die
komponente wat gebruik word in die ontwerp en konstruksie van volledige SPD's of ander SPD
gemeentes.

Wat is die UL-kortstroomstroomwaarde (SCCR)?prosurge2017-10-31T16:52:02+08:00

Wat is die UL-kortstroomstroomwaarde (SCCR)?

SSCR-kort stroombaan aanslag. Die geskiktheid van 'n SPD vir gebruik op 'n wisselstroomkring wat in staat is om nie meer as 'n verklaarde rms simmetriese stroom teen 'n verklaarde spanning tydens 'n kortsluitingstoestand te lewer nie. SCCR is nie dieselfde as AIC (Amp onderbrekende kapasiteit). SCCR is die hoeveelheid "beskikbare" stroom wat die SPD onderhewig kan wees en veilig onder die kortsluiting van die kragbron kan koppel. Die hoeveelheid huidige "onderbreek" deur die SPD is tipies aansienlik minder as die "beskikbare" stroom.

UL 1449 en die Nasionale Elektriese Kode (NEC) vereis dat die SCCR (Kort stroomstroomgradering) op alle SPD-eenhede gemerk word. Dit is nie 'n overslaggradering nie, maar die maksimum toelaatbare stroom wat 'n SPD kan onderbreek in die geval van 'n mislukking. Die NEC / UL het 'n vereiste dat die SPD getoets en gemerk word met 'n SCCR gelyk aan of groter as die beskikbare foutstroom op daardie stadium in die stelsel.

Wat is belangrik wanneer SPD spesifiseer?prosurge2017-10-31T16:31:39+08:00

Wat is belangrik wanneer SPD spesifiseer?

Wanneer u SPD spesifiseer, moet u 'n duidelike, bondige spesifikasie spesifiseer waarin u die vereiste prestasie- en ontwerpkenmerke uiteensit. 'N Minimum spesifikasie moet insluit:

• UL surge rating

• Onderdrukkingsgradering

• Kortsluiting

• Peak surge current per modus (LN, LG, en NG)

• Spanning en konfigurasie van elektriese diens

Wat is 'n Surge Protective Device of Surge Arrestor (SPD)?prosurge2017-10-31T16:30:05+08:00

Wat is 'n Surge Protective Device of Surge Arrestor (SPD)?

SPD is 'n toestel wat ontwerp is om opwaartse energie te beperk tot elektriese toerusting. Dit doen dit deur stroomopwaartse stroom af te lei of te beperk. 'N SPD is parallel gekoppel aan die toerusting wat dit beoog om te beskerm. Sodra die opwaartse spanning sy ontwerpgradering oorskry, begin dit "klamp" en begin energie direk na die elektriese grondstelsel te voer. 'N SPD het gedurende hierdie tyd 'n baie lae weerstand en die energie aan die grond "kort". Sodra die oplewing verby is, word dit oopgemaak, dus veroorsaak dit nie stroomopbrekers nie.