EN 50708-2-4:2022
(Main)Power transformers - Additional European requirements - Part 2-4: Medium power transformer - Special tests
Power transformers - Additional European requirements - Part 2-4: Medium power transformer - Special tests
This document describes the special tests for Medium Power Transformers ≤ 3150 kVA compliant with the EN 50708 2 series: - for corrugated tank for liquid immersed transformers, - for the method of measurement of losses for one winding in Highest Voltage (HV) and windings in Lowest Voltage (LV) for liquid immersed and dry type transformers.
Leistungstransformatoren – Zusätzliche europäische Anforderungen - Teil 2-4: Mittelleistungstransformatoren – Sonderprüfungen
Transformateurs de puissance - Exigences européennes supplémentaires - Partie 2-4 : Transformateurs de moyenne puissance - Essais spéciaux
Le présent document décrit les essais spéciaux pour les transformateurs de moyenne puissance ≤ 3150 kVA conformes à la série EN 50708 2: - pour la cuve à plis pour les transformateurs immergés dans un liquide ; - pour la méthode de mesure des pertes pour un enroulement en haute tension (HT) et 2 enroulements en basse tension (BT) pour les transformateurs de type sec et les transformateurs immergés dans un liquide.
Močnostni transformatorji - Dodatne evropske zahteve - 2-4. del: Srednji močnostni transformatorji - Posebni preskusi
Ta dokument opisuje poseben preskus za srednje močnostne transformatorje ≤ 3150 kVA v skladu s skupino standardov EN 50708-2:
– za transformatorje z rezervoarjem iz valovite pločevine, potopljene v tekočino;
– za metodo merjenja izgub za eno navitje pri najvišji napetosti (HV) in dve navitji pri najnižji napetosti (LV) za transformator, potopljen v tekočino, in suhi transformator.
General Information
Overview
EN 50708-2-4:2022 is a European standard developed by the European Committee for Electrotechnical Standardization (CLC) that defines special test requirements for medium power transformers with ratings up to 3150 kVA. This standard supplements the EN 50708-2 series by specifying additional test methods tailored for liquid immersed transformers with corrugated tanks and for measuring losses on transformers with specific winding configurations.
These tests ensure transformers meet stringent reliability, safety, and energy efficiency requirements under European regulations, particularly the EU Regulation 548/2014 and its amendments. The standard is essential for manufacturers and purchasers aiming to guarantee transformer quality and compliance with energy performance directives.
Key Topics
Scope of the Standard
Focuses on special tests for medium power transformers ≤ 3150 kVA, including:- Corrugated tank tests for liquid immersed transformers.
- Loss measurement methods on transformers with one highest voltage (HV) winding and multiple lowest voltage (LV) windings.
Corrugated Tank Testing
- Simulates thermal volume variations between -25 °C and +88 °C to mimic seasonal and daily operating conditions.
- Applies an endurance test with 2,000 cycles of overpressure and underpressure measuring tank integrity under fluctuating liquid volumes.
- Includes a leakage test under increased pressure for 24 hours to ensure no fluid leaks or cracks occur.
- Mandates pressure monitoring to verify structural stability and detect permanent deformations.
Measurement of Transformer Losses for Double LV Windings
- Provides a standardized method for transformers featuring one HV winding and two identical LV windings, common in solar energy applications.
- Specifies conditions where winding impedances differ by no more than 20%, enabling simplified loss measurement techniques.
- Describes procedures for resistance measurement and evaluation of load losses and short circuit impedance.
- Includes instructions for additional impedance measurements between individual windings and their coupling.
Normative References
Relies on key standards such as EN 50708-1-1, EN 60076-1:2011, IEC 60076-8, and EN IEC 60076-11:2018 for general transformer requirements and testing methods.
Applications
Transformer Manufacturers
Utilize EN 50708-2-4:2022 to design and verify medium power transformers that comply with EU energy efficiency regulations and exhibit long-term reliability.Quality Assurance and Testing Laboratories
Implement special tests outlined in this standard to validate tank durability against pressure variations and accurately measure losses, ensuring transformers meet required specifications.Energy Sector and Utilities
Use compliant transformers in distribution networks, especially where medium power transformers with double LV windings are employed, including renewable energy setups like solar plants.Purchasers and Specifiers
Refer to this standard to establish contract requirements for transformer performance, ensuring longevity, safety, and optimized energy consumption.
Related Standards
EN 50708 Series
Covers additional European requirements for power transformers across different power classes and types:- EN 50708-1-1: Common general requirements.
- EN 50708-2-1: General requirements for medium power transformers.
- EN 50708-3-1: General requirements for large power transformers.
EN 60076 (IEC 60076) Series
The fundamental international standards on power transformer testing and design:- EN 60076-1: General requirements for power transformers.
- IEC 60076-8: Application guide for measuring transformer losses.
- EN IEC 60076-11: Requirements specifically for dry-type transformers.
Keywords: EN 50708-2-4, medium power transformers, special tests, corrugated tank test, transformer losses measurement, double LV windings, liquid immersed transformers, transformer testing standards, European transformer requirements, power transformer energy efficiency, EN 60076 series, CLC standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2022
Močnostni transformatorji - Dodatne evropske zahteve - 2-4. del: Srednji
močnostni transformatorji - Posebni preskusi
Power transformers - Additional European requirements - Part 2-4: Medium power
transformer - Special tests
Transformateurs de puissance - Exigences européennes supplémentaires - Partie 2-4 :
Transformateurs de moyenne puissance - Essais spéciaux
Ta slovenski standard je istoveten z: EN 50708-2-4:2022
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN 50708-2-4
NORME EUROPÉENNE
EUROPÄISCHE NORM September 2022
ICS 29.180
English Version
Power transformers - Additional European requirements - Part 2-
4: Medium power transformer - Special tests
Transformateurs de puissance - Exigences européennes Leistungstransformatoren - Zusätzliche europäische
supplémentaires - Partie 2-4 : Transformateurs de moyenne Anforderungen - Teil 2-4: Mittelleistungstransformatoren -
puissance - Essais spéciaux Sonderprüfungen
This European Standard was approved by CENELEC on 2022-07-25. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50708-2-4:2022 E
Contents Page
Contents . 3
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Service conditions . 6
5 Special test for corrugated tank . 6
5.1 General information . 6
5.2 Temperature variation . 6
5.3 Sealing temperature . 7
5.4 Calculation of the liquid volume variation . 7
5.5 Test procedure . 7
5.5.1 General . 7
5.5.2 Measurement of pressure range . 7
5.5.3 Endurance test . 8
5.5.4 Leakage test . 8
5.5.5 Evaluation of the tests . 8
6 Method of measurement of losses on double LV windings . 8
6.1 Introduction . 8
6.2 Limits of this method . 8
6.3 Resistance measurement . 8
6.4 Measurement of load losses and short circuit impedance . 9
Bibliography . 10
European foreword
This document (EN 50708-2-4:2022) has been prepared by CLC/TC 14 “Power transformers”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2023-07-25
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2025-07-25
conflicting with this document have to be
withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Introduction
This document defines the rules for the assessment of energy performance to ensure the product
conformity to the EU Regulation 548/2014 and amendment of 2019.
Regulation leads to have a minimum level of energy performances of power transformers.
NOTE In the document the term Regulation refers to the EU Regulation 548/2014 and amendment of 2019.
For the purpose of this document, the requirements of EN 50708-1-1 apply.
This document contains particular requirements for specific transformers or transformer applications,
which are based on the requirements of EN 50708-1-1.
This document should be considered in conjunction with the requirements of the general parts.
The particular requirements of the different sub parts of EN 50708 supplement, modify or replace
certain requirements of the general parts of EN 50708-1 and/or EN 50708-1-X being valid at the time
of publication of this document. The absence of references to the exclusion of a part or a clause of a
general part means that the corresponding clauses of the general part are applicable (undated
reference).
Requirements of other -X parts with X greater than 1 being eventually relevant for cases covered by
this document also apply. This document could therefore also supplement, modify or replace certain
of these requirements valid at the time of publication of this document.
The main clause numbering of each part follows the pattern and corresponding references of
EN 50708-1-1. The numbers following the particular number of this document are those of the
corresponding parts, or clauses of the other parts of the EN 50708 series, valid at the time of
publication of this document, as indicated in the normative references of this document (dated
reference).In the case where new or amended general parts with modified numbering were published
after the sub part was issued, the clause numbers referring to a general part in sub parts might no
longer align with the latest edition of the general part. Dated references should be observed.
1 Scope
This document describes the special tests for Medium Power Transformers ≤ 3150 kVA compliant
with the EN 50708-2 series:
— for corrugated tank for liquid immersed transformers,
— for the method of measurement of losses for one winding in Highest Voltage (HV) and windings
in Lowest Voltage (LV) for liquid immersed and dry type transformers.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
EN 50708 (series), Power transformers — Additional European
...
Frequently Asked Questions
EN 50708-2-4:2022 is a standard published by CLC. Its full title is "Power transformers - Additional European requirements - Part 2-4: Medium power transformer - Special tests". This standard covers: This document describes the special tests for Medium Power Transformers ≤ 3150 kVA compliant with the EN 50708 2 series: - for corrugated tank for liquid immersed transformers, - for the method of measurement of losses for one winding in Highest Voltage (HV) and windings in Lowest Voltage (LV) for liquid immersed and dry type transformers.
This document describes the special tests for Medium Power Transformers ≤ 3150 kVA compliant with the EN 50708 2 series: - for corrugated tank for liquid immersed transformers, - for the method of measurement of losses for one winding in Highest Voltage (HV) and windings in Lowest Voltage (LV) for liquid immersed and dry type transformers.
EN 50708-2-4:2022 is classified under the following ICS (International Classification for Standards) categories: 29.180 - Transformers. Reactors. The ICS classification helps identify the subject area and facilitates finding related standards.
You can purchase EN 50708-2-4:2022 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of CLC standards.
The standard EN 50708-2-4:2022 provides a comprehensive framework for medium power transformers, specifically those with a capacity of 3150 kVA or less. Its focus on special tests ensures that transformers are assessed rigorously, promoting safety and efficiency in operations. This document caters primarily to liquid-immersed transformers with corrugated tanks and establishes the methods necessary for measuring losses in both the highest voltage (HV) and lowest voltage (LV) windings. One of the significant strengths of this standard is its alignment with the EN 50708 2 series, which adds to its credibility and relevance within the broader context of European standards. By setting forth specific testing protocols, EN 50708-2-4:2022 enhances reliability and performance in the deployment of medium power transformers, thus ensuring that they meet contemporary operational demands. The inclusion of testing methodologies for both liquid-immersed and dry-type transformers demonstrates the standard's adaptability and comprehensive nature. This versatility is crucial for manufacturers and operators in navigating varying requirements across different applications and geographical regions. Overall, EN 50708-2-4:2022 stands out as a vital document within the power transformer sector, reaffirming the importance of standardized testing in the enhancement of product quality and safety in electrical systems. Its focus on technical precision and operational effectiveness makes it an essential reference for professionals engaged in the design, manufacturing, and maintenance of medium power transformers.
표준 EN 50708-2-4:2022는 중전력 변압기(≤ 3150 kVA)의 특별 테스트에 관한 문서로, EN 50708 2 시리즈에 준수하는 액체 침적 변압기의 주름진 탱크에 대한 요구사항과 최고 전압(HV)과 최저 전압(LV)에서의 손실 측정 방법을 상세히 설명합니다. 이 문서는 중전력 변압기의 효과적인 성능 평가에 중점을 두고 있으며, 변압기 설계 및 운용 시의 신뢰성을 높이는 데 기여합니다. 이 표준의 강점은 다양한 변압기 유형을 아우르는 형식을 제공함으로써, 산업 전반에서 널리 적용될 수 있는 유연성을 갖추고 있다는 점입니다. 증류 식 또는 건식 변압기 등 다양한 환경의 요구를 충족할 수 있도록 설계되어 있어, 변압기의 신뢰성을 확보하는 데 중요한 역할을 합니다. 또한, 특별 테스트를 통해 제품의 품질 보증 및 성능 개선을 위한 중요한 기준을 제공하여, 제조업체와 최종 사용자 모두에게 이익이 되는 평가 기준을 제시합니다. EN 50708-2-4:2022는 전력 변압기 분야에서의 국제적 규범인 만큼, 유럽 내에서의 시장 진입을 위한 필수 지침으로 자리 잡고 있습니다. 이러한 점에서, 이 표준은 변압기 산업의 경쟁력을 높이고, 안전성과 효율성을 보장함으로써 관련 산업의 발전에 기여하는 중요한 문서로 평가받고 있습니다.
SIST EN 50708-2-4:2022の標準は、中容量変圧器に関する特別試験について詳述しており、これによりパワートランスフォーマーの設計と性能評価に重要な基準が提供されます。この文書は、出力が3150 kVA以下の中容量変圧器に対応しており、特に液浸変圧器の波形タンクに関する要件や、液浸型および乾式変圧器における高電圧（HV）と低電圧（LV）の巻線に対する損失測定方法が含まれています。 この標準の強みは、特別試験のための具体的なガイダンスを提供し、製品の信頼性と安全性を向上させるための基準を確立している点です。液浸変圧器の設計者や製造業者は、EN 50708 2シリーズに準拠した試験を実施することで、業界全体の信頼性と性能基準を向上させることができます。また、この文書は、技術的な詳細が明確に示されているため、実務者やエンジニアにとっても理解しやすく、適用が容易です。 さらに、環境への配慮やエネルギー効率の向上にも反映されており、持続可能なエネルギーの未来に貢献する標準となっています。このように、SIST EN 50708-2-4:2022は、変圧器の性能向上のみならず、パワートランスフォーマー関連の基準を統一する重要な役割を果たしていると言えます。
Die Norm EN 50708-2-4:2022 behandelt spezifische Anforderungen und besondere Prüfungen für Mitteltransformatoren mit einer Nennleistung von bis zu 3150 kVA. Ein zentraler Aspekt dieser Norm ist die Fokussierung auf Transformatoren, die für die Verwendung in Flüssigkeiten eingetaucht sind, insbesondere solche mit gewelltem Tankdesign. Diese detaillierte Betrachtung ist besonders relevant für Hersteller und Prüfinstitutionen, da sie sicherstellt, dass Sicherheits- und Leistungsstandards eingehalten werden. Ein wesentlicher Schwerpunkt der Norm liegt auf den Methoden zur Verlustmessung für die Wicklungen in der höchsten Spannung (HV) sowie in der niedrigsten Spannung (LV). Diese Prüfmethoden sind entscheidend, um die Effizienz und Zuverlässigkeit von Transformatoren zu gewährleisten. Durch die klare Definition der Prüfungen werden auch mögliche Unstimmigkeiten zwischen verschiedenen Prüfanstalten minimiert, was zu einer höheren Markttransparenz führt. Die Stärken der Norm EN 50708-2-4:2022 liegen somit in ihrer umfassenden und klaren Struktur, die es Fachleuten ermöglicht, die speziellen Anforderungen an Mitteltransformatoren zu verstehen und umzusetzen. Darüber hinaus fördert sie die Harmonisierung innerhalb des europäischen Marktes, indem sie einheitliche Teststandards vorgibt, die für alle Beteiligten von Bedeutung sind. Die Relevanz dieser Norm für die Branche ist unbestreitbar, da sie nicht nur die Qualität der Produkte verbessert, sondern auch zur Sicherheit und Effizienz im Betrieb von elektrischen Netzen beiträgt. Insgesamt zeigt die Norm EN 50708-2-4:2022, wie wichtig spezielle Tests sind, um die Leistungsfähigkeit und Sicherheit von Mitteltransformatoren in verschiedenen Anwendungen zu gewährleisten und hebt die Notwendigkeit hervor, diese speziellen Anforderungen kontinuierlich zu überprüfen und anzupassen.
La norme EN 50708-2-4:2022 traite des exigences supplémentaires applicables aux transformateurs de puissance moyenne, spécifiquement pour les transformateurs d'une capacité allant jusqu'à 3150 kVA. Ce document se concentre sur les tests spéciaux, qui sont essentiels pour garantir la conformité et la performance des transformateurs. L’étendue de la norme couvre principalement deux aspects. D’une part, elle aborde les transformateurs à immersion liquide avec réservoir ondulé, et d’autre part, elle définit les méthodes de mesure des pertes pour un enroulement en Haute Tension (HT) et les enroulements en Basse Tension (BT) pour les transformateurs à immersion liquide ainsi que pour les transformateurs de type sec. Cette double approche assure que les transformateurs sont testés de manière rigoureuse, ce qui est capital pour leur efficacité énergétique et leur fiabilité. Les points forts de cette norme incluent son cadre rigoureux et son alignement avec la série EN 50708 2, garantissant ainsi une harmonisation avec d’autres exigences européennes en matière de transformateurs de puissance. Les tests spéciaux décrits dans le document permettent de détecter d’éventuelles anomalies et de valider la performance, ce qui est crucial pour les utilisateurs finaux et les fabricants. En ce qui concerne la pertinence de cette norme, elle répond à des besoins croissants dans l'industrie énergétique, où l'efficacité et la durabilité des transformateurs sont de plus en plus exigées. La norme EN 50708-2-4:2022 permet aux fabricants de s'assurer que leurs produits respectent les spécificités imposées par le marché, tout en offrant une assurance de qualité aux utilisateurs. Par conséquent, cette norme joue un rôle clé dans l'amélioration des standards de performance des transformateurs à moyenne puissance en Europe.
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