SIST EN 50719:2024

Connecting terminal flags for bushings from 250A to 4 000 A for insulating liquid filled transformers

This document is applicable to vertical connecting terminal flags for insulated bushings with rated currents from 250 A to 4 000 A and frequencies from 15 Hz to 60 Hz for liquid immersed equipment.

Durchführungen bis 1 kV und von 250 A bis 5 kA für flüssigkeitsgefüllte Transformatoren

Cosses à drapeau pour traversées de 250 A à 4 000 A pour les transformateurs à remplissage de liquide isolant

Le présent document s'applique aux cosses à drapeau vertical des traversées isolées pour des courants assignés compris entre 250 A et 4 000 A et des fréquences comprises entre 15 Hz et 60 Hz utilisées avec des équipements immergés dans un liquide.

Povezovalni ploščati priključki za skoznjike od 250 A do 4000 A za transformatorje, polnjene z izolacijsko tekočino

Ta standard se uporablja za navpične povezovalne ploščate priključke za izolirane skoznjike z nazivnim tokom od 250 A do 4000 A in frekvenco od 15 Hz do 60 Hz za opremo, potopljeno v tekočino.

General Information

• Status: Published
• Public Enquiry End Date: 30-Mar-2023
• Publication Date: 12-Jun-2024
• ICS: 29.080.20 - Bushings
• ICS: 29.180 - Transformers. Reactors
• Technical Committee: IZL - Insulators
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 19-Mar-2024
• Due Date: 24-May-2024
• Completion Date: 13-Jun-2024
• Ref Project: EN 50719:2024 - Connecting terminal flags for bushings from 250 A to 4 000 A for insulating liquid filled transformers

Overview

EN 50719:2024 (CLC) defines requirements for vertical connecting terminal flags for insulated bushings used on insulating liquid‑filled transformers. It covers flags with rated currents from 250 A to 4 000 A and operating frequencies from 15 Hz to 60 Hz. The standard specifies materials, manufacturing practices, interchangeability dimensions, surface finish and testing to ensure safe, reliable electrical and mechanical connection between bushings and external conductors.

Key Topics and Requirements

• Scope and definition
  • Applies to vertical connecting flags (plate parallel to bushing axis) for liquid‑immersed equipment.
  • Standard rated currents: 250, 630, 1 250, 2 000, 3 150, 4 000 A.
• Materials & manufacturing
  • Flag body: brass CUZn40Pb2 (CW617N) in accordance with EN 12165:2016.
  • Fasteners (screws, washers): stainless steel A4 (A2 allowed by agreement).
  • Forging preferred over casting.
• Geometry & interchangeability
  • Common flag dimensions and screw sizes are provided per rated type (e.g., M10 and M12 screws for higher ratings).
  • Tolerances per ISO 2768 (medium) to support interchangeability.
  • Un‑dimensioned details may vary by manufacturer; critical features are the connecting plate and threads.
• Surface & finishing
  • Flags are unplated by default; tin or silver plating allowed by agreement.
  • Connecting plate roughness: < 3.2 μm.
  • All sharp edges must be rounded; bodies include a cut to ensure correct clamping.
• Testing
  • Type tests: temperature rise tests performed on a bushing/flag assembly in accordance with EN 60137.
  • Acceptance criteria: temperature and temperature‑rise limits are given in Table 1 of EN 50719:2024 (different limits for uncoated, tinned and silver‑plated terminals and for Ir < 4 000 A versus Ir = 4 000 A).
  • Routine tests: visual inspection and dimensional checks.

Applications and Who Uses It

• Transformer manufacturers and design engineers specifying bushings and terminal connections for liquid‑filled power transformers and reactors.
• Bushing and flag component manufacturers needing to ensure interchangeability and compatibility with EN 60137 bushings.
• Testing laboratories and procurement/specification teams in utilities and OEMs verifying temperature‑rise performance, material conformity and mechanical dimensions.
• Maintenance and installation teams ensuring correct replacement parts and safe clamping of external conductors.

Related Standards

• EN 60137 - insulated bushings for voltages above 1 000 V (referenced for temperature tests)
• EN 12165:2016 - copper alloys (CW617N)
• ISO 2768 - general tolerances
• Bibliography references: EN 50180 (series) and EN 50386 (related bushing ranges)

Keywords: EN 50719:2024, connecting terminal flags, insulated bushings, liquid‑filled transformers, rated currents 250–4000 A, temperature rise tests, CW617N brass, interchangeability.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2024
Povezovalni ploščati priključki za skoznjike od 250 A do 4000 A za transformatorje,
polnjene z izolacijsko tekočino
Connecting terminal flags for bushings from 250A to 4 000 A for insulating liquid filled
transformers
Durchführungen bis 1 kV und von 250 A bis 5 kA für flüssigkeitsgefüllte Transformatoren
Cosses à drapeau pour traversées de 250 A à 4 000 A pour les transformateurs à
remplissage de liquide isolant
Ta slovenski standard je istoveten z: EN 50719:2024
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 50719
NORME EUROPÉENNE
EUROPÄISCHE NORM March 2024
ICS 29.180
English Version
Connecting terminal flags for bushings from 250 A to 4 000 A
for insulating liquid filled transformers
Cosses à drapeau pour traversées de 250 A à 4 000 A pour Anschlussfahnen für Durchführungen von 250 A bis 4 000 A
les transformateurs à remplissage de liquide isolant für flüssigkeitsgefüllte Transformatoren
This European Standard was approved by CENELEC on 2024-02-12. 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
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50719:2024 E
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Requirements . 4
4.1 Manufacturing process . 4
4.2 Material . 4
4.3 General requirements . 4
4.4 Standard values of rated current (Ir) . 5
4.5 Compliance. 5
5 Flag common dimensions . 5
5.1 General . 5
5.2 Type 250 A . 6
5.3 Type 630 A . 7
5.4 Type 1 250 A . 8
5.5 Type 2 000 A . 9
5.6 Type 3 150 A .10
5.7 Type 4 000 A .11
6 Tests .12
6.1 Type tests .12
6.1.1 Temperature rise tests .12
6.1.2 Acceptance .12
6.2 Routine tests .12
Bibliography .13
European foreword
This document (EN 50719:2024) has been prepared by CLC/TC 36A “Insulated bushings”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2025-02-12
...