Промышленная зона Вэньян Юэцин Вэньчжоу 325000
Рабочие часы
Понедельник - пятница: 7AM - 7PM
Выходные: 10AM - 5PM
Промышленная зона Вэньян Юэцин Вэньчжоу 325000
Рабочие часы
Понедельник - пятница: 7AM - 7PM
Выходные: 10AM - 5PM

УЗИП постоянного тока может выглядеть просто снаружи, но маркировка на его этикетке содержит важную информацию о том, где его можно использовать и каковы его эксплуатационные характеристики.
Рассмотрим этот пример для солнечного УЗИП постоянного тока на 1000 В:
Ucpv: 1000 В пост. тока
Класс II
In: 20кА
Imax: 40кА
Up: 4,0 кВ
Iscpv: 10 кА
от -40°C до +85°C
Для помещений, IP20
Для опытного инженера-электрика эти аббревиатуры хорошо знакомы.
Однако для покупателя, дистрибьютора, монтажника солнечных электростанций или специалиста по закупкам они могут легко стать источником путаницы.
Означает ли Класс II устройство защиты от перенапряжения (УЗИП) второго класса?
Является ли 40 кА Imax автоматически лучше, чем 20 кА?
Почему на одном и том же УЗИП указаны оба значения 1000V и 4,0 кВ?
Означает ли Iscpv 10 кА означает ли это, что УЗИП может выдержать импульс тока молнии 10 кА?
Короткий ответ: ни одно число не описывает УЗИП целиком.
Характеристики УЗИП постоянного тока следует рассматривать как полный набор электрических параметров. Если вы новичок в области защиты от перенапряжений, сначала разберитесь, как работает УЗИП постоянного тока в фотоэлектрической системе, это поможет легче понять данные спецификации.
В этом руководстве объясняется, как правильно читать эти маркировки, используя УЗИП постоянного тока класса II на 1000 В в качестве практического примера.
Посмотрите это краткое руководство, чтобы узнать, как читать основные маркировки на паспортной табличке УЗИП постоянного тока.
Прежде чем переходить к техническим деталям, в таблице ниже представлен простой обзор.
| Маркировка | Пример | Простое значение |
|---|---|---|
| Ucpv | 1000 В ПОСТОЯННОГО ТОКА | Максимальное длительное рабочее напряжение для фотоэлектрических систем |
| Класс II | Класс II | УЗИП класса испытаний II, соответствующее защите от перенапряжений типа 2 |
| На сайте | 20 кА | Номинальный разрядный ток |
| Imax | 40 кА | Максимальный разрядный ток |
| Вверх | 4,0 кВ | Заявленный уровень напряжения защиты |
| Iscpv | 10 кА | Номинальный ток короткого замыкания УЗИП в фотоэлектрических системах |
| Температура | от -40°C до +85°C | Заявленный диапазон рабочих температур |
| Влажность | 5%–95% | Заявленный диапазон влажности |
| Для использования внутри помещений | Для использования внутри помещений | Предназначено для условий установки с защитой |
| IP20 | IP20 | Степень защиты корпуса УЗИП |

Самый важный момент:
Не сравнивайте УЗИП постоянного тока только по наибольшему значению кА, указанному на этикетке.
Например, Imax 40 кА, In 20 кА и Iscpv 10 кА все они используют единицу измерения кА, но описывают совершенно разные характеристики.
Когда покупатели впервые видят технический паспорт УЗИП, они часто начинают с самого большого числа.
Обычно это неверный подход.
Более полезный порядок чтения:
Такой порядок позволяет отсеять неподходящие изделия до сравнения основных показателей импульсного тока.
VIOX использует аналогичный подход “сначала отклонять несовместимые спецификации” в своем руководстве по техническим данным; для фотоэлектрических систем эта логика становится еще более важной, поскольку Ucpv и поведение при коротком замыкании фотоэлектрических модулей требуют особого внимания.
Одной из первых маркировок на примере этикетки является:
Класс II
Это не не означает второсортное качество.
Класс I, класс II и класс III относятся к стандартизированным классификациям испытаний УЗИП, а не к уровням качества продукции.
Для устройств защиты от перенапряжений в фотоэлектрических системах УЗИП типа 2 связано с испытаниями класса II.
Именно поэтому разные производители или технические паспорта могут использовать такие обозначения, как:
Они относятся к тесно связанным концепциям классификации и испытаний, хотя технически “Тип” и “класс испытаний” — это не просто два разных написания одного и того же термина.
Для большинства покупателей практическую взаимосвязь можно понять следующим образом:
| Классификация УЗИП | Класс испытаний | Основной параметр тока | Стандартная форма испытательной волны |
|---|---|---|---|
| Тип 1 | Класс I | Iimp | 10/350 мкс |
| Тип 2 | Класс II | In / Imax | 8/20 мкс |
| Тип 3 | Класс III | Другие параметры согласованных испытаний | Испытание комбинированной волной |

Для примера в данной статье:
Класс II → направление применения Тип 2
и поэтому наиболее важными указанными параметрами тока являются:
In = 20 кА
Imax = 40 кА
Нет.
Это одно из самых распространенных заблуждений при сравнении УЗИП.
Термины «класс I» и «класс II» могут звучать как ранжирование:
Класс I = лучше
Класс II = дешевле или слабее
Классификация УЗИП работает не так.
Они предназначены для различных условий возникновения импульсных перенапряжений.
УЗИП типа 1 / класса I оценивается по способности выдерживать импульсный ток молнии, когда в точке установки может потребоваться отвод части тока молнии.
УЗИП типа 2 / класса II обычно используется для ограничения переходных перенапряжений, вызванных наведенными эффектами молнии и коммутационными процессами.
Поэтому правильный вопрос звучит не так:
Какой класс лучше?
А в том:
Какой тип УЗИП требуется в данной точке установки?
УЗИП типа 1 не всегда является автоматически правильным выбором для любой фотоэлектрической установки, а УЗИП типа 2 не является автоматически недостаточным только потому, что существует тип 1.
Если вам нужно подробное объяснение этого вопроса выбора, ознакомьтесь с нашим руководством:
УЗИП постоянного тока типа 1, типа 2 и типа 1+2 для солнечных фотоэлектрических систем
Ваша текущая статья более подробно рассматривает воздействие молнии, место установки и случаи, когда следует оценивать необходимость применения устройств типа 1.
The biggest technical difference becomes clearer when we look at the test current.
A Type 1 SPD is associated with an impulse-current rating:
Iimp
and a 10/350 мкс current waveform is commonly associated with Class I testing.
The 10/350 μs waveform represents a much different current-energy duty than the 8/20 μs waveform used for Type 2 evaluation.
Это означает:
Iimp cannot be directly compared with Imax just because both are shown in kA.
Например:
Iimp = 12.5kA
и
Imax = 40 кА
do not mean that the 40kA Type 2 product is “stronger.”
They refer to different test waveforms and different performance characteristics.
A Type 2 SPD is mainly characterized using:
The 8/20 μs current waveform is associated with Class II discharge-current testing.
Type 2 DC SPDs are commonly evaluated for use in locations such as:
However, the final SPD type must still depend on the actual lightning protection design and installation conditions.

Class III exists within general SPD classification, but it should not become the main subject when discussing typical PV DC SPD selection.
Class III protection is generally associated with coordinated fine protection close to sensitive equipment.
For solar PV DC protection, buyers will much more commonly encounter:
That is why this article focuses mainly on Class II and its relationship with Type 2 DC SPDs, rather than treating Class I, II and III as three equally common PV product categories.
The example label shows:
Ucpv: 1000 В пост. тока
Ucpv means:
Maximum Continuous Operating Voltage for PV Application
In simple terms:
Ucpv tells you the maximum DC voltage that may be continuously applied to the SPD’s mode of protection.
IEC 61643-32 defines Ucpv in essentially this way and states that it must be equal to or higher than the maximum PV open-circuit voltage condition relevant to the installation.
This makes Ucpv one of the first specifications that should be checked when selecting a solar DC SPD.
Не обязательно.
This is important.
A PV system should not be evaluated using only a convenient nominal label such as:
1000V solar system
The actual maximum DC voltage of a PV string depends on factors including:
PV module open-circuit voltage normally increases when temperature falls.
For a broader explanation of PV array voltage, string design and related system requirements, see our IEC 62548 PV array design guide.
Therefore, the selection process should be based on the maximum calculated PV open-circuit voltage, rather than simply copying the nominal inverter or system voltage.
A simplified workflow is:
Module Voc
→ Количество модулей, соединенных последовательно
→ Low-temperature correction
→ Maximum PV open-circuit voltage
→ Select suitable Ucpv
We have already covered this subject separately in our DC SPD Voltage Selection Guide, including 600V, 1000V and 1500V DC applications.
So in this article, the important point is simply:
Ucpv is a continuous-voltage compatibility rating, not a surge-current rating.
This is another common source of confusion.
Our example SPD shows:
Ucpv = 1000V DC
и
Up = 4.0kV
A buyer may reasonably ask:
Why does a 1000V SPD also have a 4kV voltage rating?
Because these two values describe different things.
| Параметр | Пример | Что это описывает |
|---|---|---|
| Ucpv | 1000 В ПОСТОЯННОГО ТОКА | Continuous PV operating voltage |
| Вверх | 4,0 кВ | Voltage protection level during surge testing |

Итак:
Ucpv is about surviving normal system operation.
Up is about limiting transient surge voltage.
They should never be treated as interchangeable voltage ratings.
The label shows:
In: 20кА
In means:
Номинальный ток разряда
For a Type 2 / Class II SPD, In is associated with an форма волны тока 8/20 мкс.
In technical terms, it represents the crest value of the current through the SPD having the specified 8/20 μs waveshape under the relevant standardized test conditions.
That definition is accurate, but for a buyer it can be simplified:
In is one of the main ratings used to describe the tested surge-discharge performance of a Type 2 SPD.
For this product:
In = 20 кА
The important word here is nominal.
It should not be confused with Imax.
The same SPD also shows:
Imax: 40кА
Imax means:
Максимальный ток разряда
For a Type 2 SPD, Imax is also normally associated with the форма волны тока 8/20 мкс.
It represents the manufacturer’s declared maximum discharge-current capability under the applicable test conditions.
Поэтому:
In 20kA and Imax 40kA are not duplicate specifications.
They represent different test-duty levels.
This is one of the most important parts of the entire datasheet.
Consider the example:
| Параметр | Значение |
|---|---|
| На сайте | 20 кА |
| Imax | 40 кА |
| Форма волны | 8/20 мкс |

A simple way to understand them is:
На сайте = nominal discharge-current rating.
Imax = maximum declared discharge-current rating.
One common purchasing mistake is to look only at Imax because it is the larger number.
Например:
SPD A: In 20kA / Imax 40kA
SPD B: In 10kA / Imax 40kA
A buyer may see “40kA” on both products and assume that their surge performance is equivalent.
That conclusion is incomplete.
The full declared performance needs to be checked.
VIOX makes the same useful procurement distinction in its SPD datasheet guide: In and Imax should be read separately, and Imax should not be interpreted as the SPD’s normal repeated discharge capacity.
Нет.
This is probably the most useful purchasing rule in this article:
The highest kA value does not automatically identify the best SPD.
Suppose two products are advertised as:
It would be incorrect to select SPD B immediately just because:
60kA > 40kA.
Other questions still matter:
A larger number may be useful when the complete design calls for it.
But:
More kA is not a substitute for correct coordination.
Not simply because it says 40kA.
This is another very common mistake.
A Type 2 product may show:
Imax = 40kA, 8/20 μs
while a Type 1 product may show:
Iimp = 12.5kA, 10/350 μs
Looking only at the peak current numbers:
40 > 12.5
may make the Type 2 SPD appear stronger.
But that comparison is technically incorrect.
The two values are based on different test waveforms and different protection duties.
Поэтому:
Imax cannot be used as a substitute for a specified Iimp requirement.
If the project requires Type 1 lightning-current capability, a large Type 2 Imax value alone does not satisfy that requirement.
The example label shows:
Up: 4,0 кВ
Up means:
Уровень защиты по напряжению
It describes the SPD’s declared voltage-limiting performance under specified standardized test conditions.
In practical terms, Up helps answer the question:
How effectively does the SPD limit the transient voltage during the relevant test?
Generally, a lower Up can provide a lower level of surge voltage at the SPD terminals.
However, this needs an important qualification.
The printed Up value should не be treated as the exact maximum voltage that every connected inverter or device will experience in a real installation.
Почему?
Because the actual voltage seen by the protected equipment can also be affected by:
VIOX correctly makes the same distinction: the declared Up is established at the SPD under standardized conditions, while installation conductors can increase the voltage presented to the protected equipment.
Not by itself.
It is reasonable to prefer effective voltage limitation, but the selection must remain compatible with the complete electrical system.
A low Up does not compensate for:
So instead of saying:
“Always buy the SPD with the lowest Up.”
A more technically correct rule is:
Select an SPD with a suitable Up while also verifying Ucpv, SPD Type, protected equipment withstand level and installation coordination.
Now we come to one of the most misunderstood PV-specific parameters:
Iscpv: 10 кА
This is particularly important because it also uses the unit kA.
It is easy to look at:
In 20 кА
Imax 40 кА
Iscpv 10 кА
and assume they are three levels of surge current.
Это не так.
Iscpv means:
Short-Circuit Current Rating of the SPD for the PV application.
IEC terminology defines Iscpv as the maximum prospective short-circuit current from the power system for which the SPD, together with the specified disconnector, is rated.
A simpler explanation is:
Iscpv tells you whether the SPD and its specified disconnection arrangement are suitable for the prospective PV short-circuit current at the installation point.
Это fault-current / short-circuit characteristic.
It is not a lightning-surge rating.

This distinction deserves to be stated clearly:
Iscpv ≠ Imax
Even though both can be expressed in kA.
Например:
Describes surge discharge-current performance.
Describes the SPD’s PV short-circuit-current rating in conjunction with the specified disconnection arrangement.
So on our example product:
Imax = 40 кА
does not mean:
PV short-circuit rating = 40kA.
And:
Iscpv = 10kA
does not mean:
The SPD can only discharge a 10kA surge.
These numbers belong to different electrical events.
PV DC circuits behave differently from ordinary AC circuits.
One important difference is that DC current does not naturally pass through zero every half-cycle as AC current does.
For protection devices, switching equipment and disconnecting arrangements, this makes DC fault interruption an important design consideration.
That is one reason PV-specific SPDs have characteristics and test requirements beyond simply printing:
“DC 1000V”
on an AC-style product.
IEC 61643-31 is specifically intended for SPDs connected to the DC side of photovoltaic installations and establishes PV-specific requirements, ratings and test methods.
Therefore, when buying a PV SPD, do not ask only:
“Is this 1000V DC?”
Also ask:
What is the declared Iscpv and required disconnection arrangement?
The easiest way to remember these parameters is with this table:
| Рейтинг | Main Meaning | Typical Context |
|---|---|---|
| На сайте | Номинальный разрядный ток | Type 2 / Class II surge performance |
| Imax | Максимальный разрядный ток | Type 2 maximum declared surge-current performance |
| Iimp | Impulse current | Type 1 / Class I lightning-current capability |
| Iscpv | PV short-circuit current rating | PV fault-current compatibility |
Notice something important:
Three or four specifications can all contain:
kA
but this does not mean they can be compared directly.
Before comparing any two kA ratings, first ask:
This prevents a large number of purchasing errors.
The label also declares:
от -40°C до +85°C
This is the manufacturer’s declared temperature range for the product.
Environmental ratings should not be ignored simply because electrical parameters look correct.
PV equipment may be installed in:
The internal temperature of an enclosure can be very different from the normal outdoor air temperature.
Therefore, project engineers should confirm that the SPD’s declared environmental conditions are suitable for the actual enclosure and installation environment.
Where the datasheet declares:
5%–95%
this normally represents the manufacturer’s declared relative humidity operating range.
However, humidity specifications should always be read together with conditions such as:
The percentage alone does not mean that an exposed SPD can be installed directly in rain or other outdoor environments.
The label states:
Для использования внутри помещений
This does not necessarily mean that the SPD can never form part of an outdoor PV installation.
It means the SPD itself is intended for a protected environment according to its declared construction and installation conditions.
For example, an indoor-rated SPD may be installed inside:
The important distinction is:
The SPD can be inside outdoor equipment without the SPD itself being directly exposed to outdoor conditions.
IP20 is the enclosure protection rating shown for the SPD itself.
It should not be interpreted as a weatherproof rating.
A DIN-rail SPD with IP20 is normally installed inside another suitable enclosure or cabinet.
For an outdoor PV installation, the final environmental protection depends on the complete enclosure, not only the bare SPD module.
Итак:
IP20 SPD inside a suitable outdoor enclosure
can be a normal arrangement.
But:
IP20 SPD directly exposed to rain, dust and outdoor weather
should not be assumed to be acceptable.

Now we can return to the original example.
Ucpv: 1000 В пост. тока
Класс II
In: 20кА
Imax: 40кА
Up: 4,0 кВ
Iscpv: 10 кА
Instead of reading each number independently, read it as one technical description.
This tells us the declared maximum continuous PV operating voltage of the SPD.
This indicates Class II testing / Type 2 application direction.
This is the nominal discharge-current rating associated with the relevant Type 2 surge test.
This is the declared maximum discharge-current rating.
This is the declared voltage protection level.
This is the PV short-circuit-current rating and must be understood together with the applicable disconnector/protection arrangement.
Now the label makes much more sense.
It is not saying:
“1000V, 20kA, 40kA, 10kA — bigger numbers are better.”
It is describing different electrical functions and limits of the same SPD.
Incorrect:
Class I is premium and Class II is lower quality.
Correct:
Class I and Class II represent different test/protection classifications.
Incorrect:
This one says 60kA, so it is automatically better than the 40kA model.
Correct:
Check:
before making the comparison.
Incorrect:
Imax 40kA is higher than Iimp 12.5kA, so Type 2 is stronger.
Correct:
Iimp and Imax refer to different test waveforms and different surge duties.
Incorrect:
The SPD is rated 1000V but Up is 4kV, so the specifications conflict.
Correct:
Ucpv and Up describe different voltage characteristics.
Incorrect:
Iscpv 10kA means the SPD can discharge 10kA of lightning current.
Correct:
Iscpv is a PV short-circuit-current rating.
Even a correctly selected SPD can provide poor protection if installation is poor.
Important details include:
A datasheet tells you what the device is capable of under defined conditions.
Installation determines how effectively that capability is used in the real system.
The SPD should also be considered together with other solar PV electrical protection devices, including DC fuses, isolators, circuit breakers and the overall protection arrangement.

For buyers, distributors and EPC procurement teams, the following sequence is more useful than simply asking for:
“1000V 40kA SPD price.”
Is the product specifically intended for:
PV DC surge protection?
Do not assume an AC SPD with a similar voltage or current marking is interchangeable.
Determine the maximum possible PV open-circuit voltage.
Then confirm that the selected Ucpv is suitable.
For the full calculation method, refer to the DC SPD Voltage Selection Guide mentioned earlier.
Determine whether the installation requires:
Do not make this decision simply from product price or kA rating.
Our detailed Type 1 vs Type 2 vs Type 1+2 DC SPD guide explains this separately.
For a Type 2 / Class II SPD, confirm both values.
Do not check only Imax.
Verify the declared voltage protection level and whether it is appropriate for the protected equipment and protection concept.
Confirm that the SPD and specified disconnection/protection arrangement are compatible with the prospective short-circuit current of the PV system.
Confirm:
Проверьте:
For PV DC SPDs, IEC 61643-31 is an important product standard to check.
IEC 61643-31:2018 covers SPDs intended for the DC side of photovoltaic installations up to 1500V DC, while IEC 61643-32:2017 addresses their selection, installation and coordination.
Depending on the project and market, buyers may also need:
Do not assume that a logo printed on a product is sufficient evidence.
Match the documentation to the exact model being purchased.
Before approving a PV SPD, use the following checklist.
| Проверьте | Вопрос |
|---|---|
| Приложение | Is it specifically suitable for PV DC? |
| Ucpv | Is it suitable for maximum PV open-circuit voltage? |
| Тип СПД | Does Type 1 / Type 2 / Type 1+2 match the installation design? |
| Класс испытаний | Is the declared classification clear? |
| На сайте | Is the nominal discharge-current rating specified? |
| Imax | Is the maximum discharge-current rating specified? |
| Iimp | If Type 1 is required, is Iimp declared? |
| Вверх | Is the protection level suitable? |
| Iscpv | Is the PV short-circuit rating adequate? |
| Проводка | Is the correct DC connection diagram available? |
| Защита | Is required backup protection identified? |
| Окружающая среда | Are temperature, IP and enclosure conditions suitable? |
| Стандарт | Is the applicable PV SPD standard stated? |
| Документация | Do certificates/test reports match the exact model? |
A weak RFQ might say:
Please quote 1000V 40kA solar SPD.
This leaves many important questions unanswered.
A better RFQ is:
Please quote a Type 2 / Class II PV DC SPD for a 1000V DC application. Please confirm Ucpv, In, Imax, Up, Iscpv, pole configuration, required backup protection, IEC 61643-31 documentation and wiring diagram.
If known, also include:
This allows the manufacturer to evaluate the complete requirement instead of matching only the words:
“1000V” and “40kA.”
They are closely related but technically describe classification/testing from slightly different perspectives.
For practical PV product selection, a Type 2 SPD is associated with испытаниями класса II, which is why labels and datasheets may show Type 2, T2 or Class II terminology.
Нет.
Class I and Class II are not quality levels.
They are intended for different surge-protection duties and test conditions.
In is the nominal discharge current.
Imax is the maximum discharge current.
For Type 2 SPDs, both are normally associated with the 8/20 μs waveform, but they represent different test-duty levels.
Not enough information is available to answer that from Imax alone.
A proper comparison also requires Ucpv, Type, In, Up, Iscpv, standard, protection configuration and installation conditions.
Not simply because its peak current number is larger.
Type 1 is characterized by lightning impulse-current capability such as Iimp and the associated Class I test conditions.
Imax and Iimp should not be directly compared.
Ucpv is the maximum continuous operating voltage for the PV application.
Вверх is the declared voltage protection level under specified surge test conditions.
They perform completely different functions in the datasheet.
Iscpv is the short-circuit current rating of the PV SPD.
More precisely, it describes the maximum prospective short-circuit current for which the SPD, together with its specified disconnector arrangement, is rated.
Нет.
Imax is a surge discharge-current rating.
Iscpv is a short-circuit-current rating.
The fact that both use kA does not make them interchangeable.
Not automatically.
Maximum PV open-circuit voltage should be calculated under the project’s design conditions before selecting Ucpv.
For more detail, see our Руководство по выбору устройств защиты от импульсных перенапряжений (УЗИП) постоянного тока: как выбрать правильное номинальное напряжение.
It may be installed inside a suitable outdoor enclosure, provided the complete installation satisfies the required environmental protection.
IP20 on the SPD itself should not be treated as a weatherproof outdoor rating.
IEC 61643-31 covers requirements and test methods for SPDs intended for the DC side of photovoltaic installations up to 1500V DC.
IEC 61643-32 provides selection and application principles for PV SPDs.
Reading a DC SPD datasheet becomes much easier once each parameter is treated according to its actual purpose.
For the example:
Класс II
Ucpv 1000 В пост. тока
In 20 кА
Imax 40 кА
Up 4.0kV
Iscpv 10 кА
the correct interpretation is not simply:
“This is a 1000V, 40kA SPD.”
A more complete interpretation is:
Each specification answers a different engineering question.
That leads to one simple purchasing principle:
Never select a DC SPD from one voltage number, one kA number or one Type label alone.
The correct SPD is the one whose complete set of ratings matches the PV system voltage, surge environment, equipment protection requirements, short-circuit conditions and installation design.
For solar PV projects requiring 600V, 1000V or 1500V surge protection, explore KUANGYA DC surge protective devices to compare available Type 2 and Type 1+2 models by voltage rating, discharge-current capability and application.