SIST EN 50243:2022
(Main)Outdoor bushings for 24 kV and 36 kV and for 5 kA and 8 kA, for liquid filled transformers
Outdoor bushings for 24 kV and 36 kV and for 5 kA and 8 kA, for liquid filled transformers
This document is applicable to ceramic insulated outdoor bushings for highest voltages for equipment of 24 kV and 36 kV, with rated currents of 5 kA and 8 kA for insulating liquid filled transformers and frequencies from 15 Hz up to 60 Hz.
This document establishes dimensions to ensure interchangeability and adequate mounting of bushings.
Two types of construction are specified, type A and type B, both types for highest voltages for equipment 24 kV and 36 kV and rated currents of 5 kA and 8 kA. The mechanical stresses of the conductor tube define the difference between type A and type B. The conductor tube of type A is axially and radially fixed in the top of the bushing. The inner line terminal of the transformer can be flexible and without any special support for the lower end of the conductor tube.
For new installations bushings of Type A are expected to be used. Type B bushings can be supplied at the request of a customer.
In case of type B, the conductor tube is only radially fixed in the top of the bushing. In that case, a rigid support is mounted to fix the lower end of the conductor tube (for example, in combination with a drip proofed sealing end). The drip proofed sealing end is often required in the service requirements. In this case, it is not possible to use type A because of the existing double fixation. Therefore, both bushing types A and B are specified.
The condition for the usage of type B is that the drip-proof sealing end is able to withstand the mechanical stress in axial direction.
Durchführungen für Freiluft, 24 kV und 36 kV sowie 5 kA und 8 kA, für flüssigkeitsgefüllte Transformatoren
Traversées d'extérieur pour 24 kV et 36 kV et pour 5 kA et 8 kA, pour transformateurs remplis de liquide
Le présent document est applicable aux traversées d'extérieur à isolation en matière céramique pour des tensions les plus élevées pour le matériel de 24 kV et 36 kV, avec des courants assignés de 5 kA et 8 kA pour les transformateurs remplis de liquide isolant et des fréquences de 15 Hz à 60 Hz.
Le présent document établit les dimensions pour assurer l'interchangeabilité et le montage correct des traversées.
Deux types de constructions sont spécifiés: le type A et le type B. Ces deux types s'appliquent pour des tensions les plus élevées pour le matériel de 24 kV et 36 kV et des courants assignés de 5 kA et 8 kA. Les contraintes mécaniques des tubes conducteurs définissent la différence entre le type A et le type B. Le tube conducteur de type A est fixé de manière axiale et radiale en haut de la traversée. La borne de ligne intérieure du transformateur peut être souple et sans support spécial pour l'extrémité inférieure du tube conducteur.
Pour les nouvelles installations, l'utilisation de traversées de type A est attendue. Des traversées de type B peuvent être fournies à la demande du client.
Dans le cas du type B, le tube conducteur est uniquement fixé de manière radiale en haut de la traversée. Dans ce cas, un support rigide est monté pour fixer l'extrémité inférieure du tube conducteur (en combinaison avec une extrémité scellée étanche, par exemple). L'extrémité étanche est souvent spécifiée dans les exigences de maintenance. Dans ce cas, il n'est pas possible d'utiliser un type A à cause de la double fixation existante. C'est pourquoi les traversées de types A et B sont spécifiées.
La condition pour l'utilisation du type B est que l'extrémité étanche soit capable de résister à la contrainte mécanique axiale.
Skoznjiki za zunanjo montažo 24 kV in 36 kV ter za 5 kA in 8 kA, za transformatorje, napolnjene s tekočino
Ta dokument se uporablja za keramično izolirane skoznjike za zunanjo montažo pri največji napetosti opreme 24 kV in 36 kV, z nazivnim tokom 5 kA in 8 kA za izoliranje transformatorjev, napolnjenih s tekočino, ter s frekvencami od 15 Hz do 60 Hz.
Določa mere za zagotavljanje zamenljivosti in ustrezne montaže skoznjikov.
V dokumentu sta določeni dve vrsti konstrukcije, tip A in tip B, pri čemer se obe uporabljata za največjo napetost opreme 24 kV in 36 kV ter nazivni tok 5 kA in 8 kA. Mehanske obremenitve cevi za vodnike določajo razliko med tipom A in tipom B. Cev za vodnike tipa A je aksialno (osno) in radialno pritrjena na zgornjem delu skoznjika. Notranji linijski zaključni element transformatorja je lahko fleksibilen in brez posebne opore za spodnji del cevi za vodnike.
Pri novih inštalacijah se pričakuje uporaba skoznjikov tipa A. Skoznjike tipa B je mogoče dobaviti na zahtevo stranke.
Pri tipu B je cev za vodnike na zgornjem delu skoznjika pritrjena zgolj radialno. V tem primeru je treba namestiti togo oporo, ki pritrdi spodnji del cevi za vodnike (npr. v kombinaciji s tesnilnim končnikom z zaščito pred kapljanjem). Tesnilni končnik z zaščito pred kapljanjem je pogosto predmet zahtev glede delovanja. V tem primeru zaradi obstoječe dvojne pritrditve ni mogoče uporabiti tipa A, zato sta določena tako skoznjik tipa A kot tipa B.
Pogoj za uporabo tipa B je, da tesnilni končnik z zaščito pred kapljanjem lahko prenese mehansko obremenitev v aksialni (osni) smeri.
General Information
Relations
Overview
EN 50243:2022 is a CLC (CENELEC) standard that specifies ceramic insulated outdoor bushings for liquid‑filled transformers rated for 24 kV and 36 kV equipment voltages and 5 kA and 8 kA rated currents. Applicable for frequencies from 15 Hz to 60 Hz, the document defines common dimensions, creepage distances and parts lists to ensure interchangeability and reliable mounting of bushings used on transformer covers and housings.
Key topics and requirements
- Ratings and scope
- Highest voltage for equipment Um: 24 kV, 36 kV
- Rated currents Ir: 5 000 A, 8 000 A
- Frequency range: 15–60 Hz
- Two construction types
- Type A: conductor tube axially and radially fixed at the top - inner terminal may be flexible. Recommended for new installations.
- Type B: conductor tube only radially fixed; requires a rigid lower support (e.g., drip‑proof sealing end) to withstand axial stress. Supplied on customer request.
- Mechanical & electrical requirements
- Bushings installed with transformer side immersed in insulating liquid and the other end in air.
- Dimensions, tolerances and component detail drawings are specified (Annex A) to guarantee mounting and interchangeability.
- Provision for arcing horns where required.
- Creepage distances & pollution
- Designated creepage distances for pollution severity levels (per IEC/TS 60815); EN 50243:2022 includes the highest pollution class.
- Parts lists and component drawings
- Detailed lists for Type A and Type B, component drawings, mounting hardware and vertical connecting flags (Annex B).
Applications and who uses it
- Transformer manufacturers specifying compatible outdoor bushings for liquid‑filled units.
- Utilities and substations ensuring replacement bushings meet mounting and creepage requirements.
- OEMs, procurement and specifiers aiming for interchangeability across transformer models.
- Testing laboratories and certification bodies for compliance checks against EN 50243:2022.
- Typical use cases: new transformer installations, retrofits where existing sealing ends or supports determine bushing type (A vs B), and environments with high pollution where increased creepage is required.
Related standards
- EN 60137 (Insulated bushings for >1 000 V)
- EN 60672‑3 (Ceramic/glass insulating materials)
- EN 62155 (Hollow ceramic/glass insulators)
- IEC/TS 60815 (Selection for polluted conditions)
- EN ISO 286‑2, ISO 261 (geometrical and thread tolerances)
EN 50243:2022 is primarily a dimensional and application standard that helps manufacturers and users choose and install the correct outdoor bushings for reliable, interoperable transformer connections.
Frequently Asked Questions
SIST EN 50243:2022 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Outdoor bushings for 24 kV and 36 kV and for 5 kA and 8 kA, for liquid filled transformers". This standard covers: This document is applicable to ceramic insulated outdoor bushings for highest voltages for equipment of 24 kV and 36 kV, with rated currents of 5 kA and 8 kA for insulating liquid filled transformers and frequencies from 15 Hz up to 60 Hz. This document establishes dimensions to ensure interchangeability and adequate mounting of bushings. Two types of construction are specified, type A and type B, both types for highest voltages for equipment 24 kV and 36 kV and rated currents of 5 kA and 8 kA. The mechanical stresses of the conductor tube define the difference between type A and type B. The conductor tube of type A is axially and radially fixed in the top of the bushing. The inner line terminal of the transformer can be flexible and without any special support for the lower end of the conductor tube. For new installations bushings of Type A are expected to be used. Type B bushings can be supplied at the request of a customer. In case of type B, the conductor tube is only radially fixed in the top of the bushing. In that case, a rigid support is mounted to fix the lower end of the conductor tube (for example, in combination with a drip proofed sealing end). The drip proofed sealing end is often required in the service requirements. In this case, it is not possible to use type A because of the existing double fixation. Therefore, both bushing types A and B are specified. The condition for the usage of type B is that the drip-proof sealing end is able to withstand the mechanical stress in axial direction.
This document is applicable to ceramic insulated outdoor bushings for highest voltages for equipment of 24 kV and 36 kV, with rated currents of 5 kA and 8 kA for insulating liquid filled transformers and frequencies from 15 Hz up to 60 Hz. This document establishes dimensions to ensure interchangeability and adequate mounting of bushings. Two types of construction are specified, type A and type B, both types for highest voltages for equipment 24 kV and 36 kV and rated currents of 5 kA and 8 kA. The mechanical stresses of the conductor tube define the difference between type A and type B. The conductor tube of type A is axially and radially fixed in the top of the bushing. The inner line terminal of the transformer can be flexible and without any special support for the lower end of the conductor tube. For new installations bushings of Type A are expected to be used. Type B bushings can be supplied at the request of a customer. In case of type B, the conductor tube is only radially fixed in the top of the bushing. In that case, a rigid support is mounted to fix the lower end of the conductor tube (for example, in combination with a drip proofed sealing end). The drip proofed sealing end is often required in the service requirements. In this case, it is not possible to use type A because of the existing double fixation. Therefore, both bushing types A and B are specified. The condition for the usage of type B is that the drip-proof sealing end is able to withstand the mechanical stress in axial direction.
SIST EN 50243:2022 is classified under the following ICS (International Classification for Standards) categories: 29.080.20 - Bushings; 29.180 - Transformers. Reactors. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 50243:2022 has the following relationships with other standards: It is inter standard links to SIST EN 50243:2004, SIST EN 50243:2004. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase SIST EN 50243:2022 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 SIST standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2022
Nadomešča:
SIST EN 50243:2004
Skoznjiki za zunanjo montažo 24 kV in 36 kV ter za 5 kA in 8 kA, za
transformatorje, napolnjene s tekočino
Outdoor bushings for 24 kV and 36 kV and for 5 kA and 8 kA, for liquid filled transformers
Durchführungen für Freiluft, 24 kV und 36 kV sowie 5 kA und 8 kA, für flüssigkeitsgefüllte
Transformatoren
Traversées d'extérieur pour 24 kV et 36 kV et pour 5 kA et 8 kA, pour transformateurs
remplis de liquide
Ta slovenski standard je istoveten z: EN 50243:2022
ICS:
29.080.20 Skoznjiki Bushings
29.180 Transformatorji. Dušilke Transformers. Reactors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN 50243
NORME EUROPÉENNE
EUROPÄISCHE NORM August 2022
ICS 29.080.20; 29.180 Supersedes EN 50243:2002
English Version
Outdoor bushings for 24 kV and 36 kV and for 5 kA and 8 kA, for
liquid filled transformers
Traversées d'extérieur pour 24 kV et 36 kV et pour 5 kA et Durchführungen für Freiluft, 24 kV und 36 kV sowie 5 kA
8 kA, pour transformateurs remplis de liquide und 8 kA, für flüssigkeitsgefüllte Transformatoren
This European Standard was approved by CENELEC on 2022-06-20. 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,
Türkiye 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 50243:2022 E
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Requirements . 5
4.1 General Requirements . 5
4.2 Ratings . 5
4.2.1 Standard values of highest voltage for equipment (Um) . 5
4.2.2 Standard values of rated current (I ) . 5
r
4.3 Common dimensions and creepage distances of bushings type A and type B . 5
4.4 Parts list according to bushing type A . 8
4.5 Parts list according to bushing type B . 9
Annex A (normative) Detail drawings of components . 10
A.1 General . 10
A.2 Insulator (Item N° 1) . 11
A.3 Conductor tube (Item N° 2) . 15
A.4 Upper cap (Item N° 4) . 16
A.5 Lower cap (Item N° 6) . 16
A.6 Nut (Item N° 3) . 17
A.7 Sealing ring (Item N° 5) . 18
A.8 Flat gasket (Item N° 9) . 18
A.9 Flat gasket (Item N° 18) . 18
A.10 Clamping ring (Item N° 16) . 19
A.11 Interlayer (Item N° 13) . 19
A.12 Compression ring (Item N° 11) . 20
A.13 Retaining ring (Item N° 12) . 21
A.14 Flat gasket (Item N° 10) . 21
A.15 Clamping paw (Item N° 17). 22
Annex B (normative) Vertical connecting flags . 23
B.1 General . 23
B.2 Vertical connecting flags – 5 000 A type TP78-120 . 23
B.3 Vertical connecting flags – 8 000 A – type TP78-180 . 24
Bibliography . 26
European foreword
This document (EN 50243:2022) has been prepared by CLC/TC 36A “Insulated bushings”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2023-06-20
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2025-06-20
conflicting with this document have to be
withdrawn
This document will supersede EN 50243:2002 and all of its amendments and corrigenda (if any).
— Addition of the highest pollution class.
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.
1 Scope
This document is applicable to ceramic insulated outdoor bushings for highest voltages for equipment of 24 kV
and 36 kV, with rated currents of 5 kA and 8 kA for insulating liquid filled transformers and frequencies from
15 Hz up to 60 Hz.
This document establishes dimensions to ensure interchangeability and adequate mounting of bushings.
Two types of construction are specified, type A and type B, both types for highest voltages for equipment
24 kV and 36 kV and rated currents of 5 kA and 8 kA. The mechanical stresses of the conductor tube define
the difference between type A and type B. The conductor tube of type A is axially and radially fixed in the top
of the bushing. The inner line terminal of the transformer can be flexible and without any special support for
the lower end of the conductor tube.
For new installations bushings of Type A are expected to be used. Type B bushings can be supplied at the
request of a customer.
In case of type B, the conductor tube is only radially fixed in the top of the bushing. In that case, a rigid
support is mounted to fix the lower end of the conductor tube (for example, in combination with a drip proofed
sealing end). The drip proofed sealing end is often required in the service requirements. In this case, it is not
possible to use type A because of the existing double fixation. Therefore, both bushing types A and B are
specified.
The condition for the usage of type B is that the drip-proof sealing end is able to withstand the mechanical
stress in axial direction.
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 12165:2016, Copper and copper alloys — Wrought and unwrought forging stock
EN 60137, Insulated bushings for alternating voltages above 1 000 V (IEC 60137)
EN 60672-3, Ceramic and glass-insulating materials — Part 3: Specifications for individual materials (IEC
60672-3)
EN 62155, Hollow pressurized and unpressurized ceramic and glass insulators for use in electrical equipment
with rated voltages greater than 1 000 V (IEC 62155)
EN ISO 286-2, Geometrical product specifications (GPS) — ISO code system for tolerances on linear sizes —
Part 2: Tables of standard tolerance classes and limit deviations for holes and shafts (ISO 286-2)
EN ISO 1101, Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form,
orientation, location and run-out (ISO 1101)
EN ISO 21920-1, Geometrical product specifications (GPS) — Surface texture: Profile — Part 1: Indication of
surface texture (ISO 21920-1)
IEC/TS 60815 (all parts), Selection and dimensioning of high-voltage insulators intended for use in polluted
conditions
ISO 261, ISO general purpose metric screw threads — General plan
ISO 2768-1, General Tolerances — Part 1: Tolerances for linear and angular dimensions without individual
tolerance indications
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
bushing type A
bushing with a conductor tube which is axially and radially fixed in the top of the bushing
3.2
bushing type B
bushing with a conductor tube which is only radially fixed in the top of the bushing
4 Requirements
4.1 General requirements
Bushings specified by this document shall be installed with the transformer side of the bushing fully immersed
in insulating liquid and the other end in air.
Bushings shall meet the requirements of EN 60137.
4.2 Ratings
4.2.1 Standard values of highest voltage for equipment (U )
m
The value of U of a bushing shall be chosen from the standard values of the highest voltage for transformers
m
given below in kilovolts:
24 - 36
4.2.2 Standard values of rated current (I )
r
The value I of a bushing shall be chosen from the standard values given below in amperes:
r
5 000 – 8 000
4.3 Common dimensions and creepage distances of bushings type A and type B
The common dimensions of bushings type A and type B shall be as specified in Figure 1 and Table 1.
The details of the components are given in Annex A.
The provisions for arcing horns should be made if required.
In case of environmental conditions, which do not require site pollution sever
...
The article discusses the specifications for outdoor bushings used in liquid-filled transformers with voltages of 24 kV and 36 kV, and rated currents of 5 kA and 8 kA. The document establishes dimensions to ensure proper mounting and interchangeability of the bushings. There are two types of construction specified, type A and type B, with the difference between them being the mechanical stresses on the conductor tube. Type A has the conductor tube fixed both axially and radially, while type B has it only radially fixed with a rigid support at the lower end. Type A is recommended for new installations, but type B can be provided upon request. However, type B can only be used if the drip-proof sealing end can withstand the mechanical stress in the axial direction.
記事のタイトル：SIST EN 50243:2022- 液体充填変圧器用の24 kVおよび36 kVの屋外ブッシュ 記事の内容：この文書は、24 kVおよび36 kVの装置のための最高電圧用のセラミック絶縁屋外ブッシュに適用されます。評価電流は5 kAおよび8 kAで、周波数は15 Hzから60 Hzまでです。 この文書は、交換性と適切なブッシュの取り付けに必要な寸法を確立します。 2つのタイプの構造が指定されており、タイプAとタイプBがあります。どちらのタイプも装置用の最高電圧は24 kVおよび36 kVで、評価電流は5 kAおよび8 kAです。両者の違いは導体管の機械的応力にあります。タイプAのブッシュは導体管が軸方向および半径方向に固定されています。変圧器の内部の線端子は柔軟であり、導体管の下端部に特別なサポートは必要ありません。 新しい設置では、タイプAのブッシュが使用されることが期待されますが、タイプBのブッシュは顧客の要求に応じて提供することができます。 タイプBの場合、導体管はブッシュの上部で半径方向にのみ固定されています。この場合、下部の導体管を固定するために剛性サポートが取り付けられます（例：防滴仕様のシールエンドとの組み合わせ）。防滴仕様のシールエンドはサービス要件でしばしば要求されます。この場合、既存の二重固定のため、タイプAは使用できません。したがって、A型およびB型の両方のブッシュが指定される必要があります。 B型を使用する条件は、防滴仕様のシールエンドが軸方向の機械的応力に耐えることができるかどうかです。
기사 제목: SIST EN 50243:2022 - 액체 충전 변압기용 24 kV 및 36 kV용 야외 부싱 기사 내용: 이 문서는 24 kV 및 36 kV 장비를 위한 최고 전압용 세라믹 절연 야외 부싱에 적용됩니다. 평가 전류는 5 kA 및 8 kA이며 주파수는 15 Hz에서 60 Hz까지입니다. 이 문서는 호환성과 부싱의 적절한 매핑을 위해 치수를 제시합니다. 두 가지 종류의 구조가 지정되어 있으며, A형과 B형이 있습니다. 두 형식 모두 장비용 최고 전압이 24 kV 및 36 kV이고, 평가 전류는 5 kA 및 8 kA입니다. 이들 간에는 도체 관의 기계적 응력에 차이가 있습니다. A형 부싱은 도체 관이 축 방향과 반경 방향으로 고정됩니다. 변압기의 내부 선 단자는 유연하게 되어 있으며, 도체 관의 하단에 특별한 지지 없이 제작됩니다. 새로운 설치에는 A형 부싱을 사용하는 것이 기대되며, B형 부싱은 고객의 요청에 따라 공급될 수 있습니다. B형의 경우, 도체 관은 부싱의 상단에서 반경 방향으로만 고정됩니다. 이 경우, 경직 지지대를 사용하여 도체 관의 하단을 고정시킵니다(예: 방수 마감된 밀봉 부분과 함께 조합). 방수 마감된 밀봉 부분은 서비스 요구 사항에서 자주 요구됩니다. 이 경우, 기존의 이중 고정 때문에 A형을 사용할 수 없습니다. 따라서 A형과 B형 부싱 모두가 지정되어야 합니다. B형 사용의 조건은 방수 마감된 밀봉 부분이 축 방향의 기계적 응력을 견딜 수 있는지 여부입니다.
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