SIST EN 2794-001:2024

Aerospace series - Circuit breakers, single-pole, temperature compensated, rated currents 20 A to 50 A - Part 001: Technical specification

This document specifies the single-pole temperature compensated circuit breakers rated from 20 A to 50 A and used in aircraft on-board circuits. It describes specific environmental, electrical and mechanical characteristics and the stringency of tests to be applied according to test methods of EN 3841 100.
These circuit breakers are intended for use in aircraft with electrical supplies in accordance with EN 2282 (all categories).

Luft- und Raumfahrt - Schutzschalter, einpolig, temperaturkompensiert, Nennströme von 20 A bis 50 A - Teil 001: Technische Lieferbedingungen

Dieses Dokument legt einpolige, temperaturkompensierte Schutzschalter mit Nennströmen von 20 A bis 50 A für den Einsatz in Luftfahrzeug-Bordnetzen fest. Es beschreibt die spezifischen Umwelt-, elektrischen und mechanischen Eigenschaften und den Umfang der entsprechend den Prüfverfahren nach EN 3841 100 durchzuführenden Prüfungen.
Diese Schutzschalter sind für den Einsatz in Luftfahrzeugen mit Stromversorgung nach EN 2282 (alle Kategorien) vorgesehen.

Série aérospatiale - Disjoncteurs unipolaires compensés en température, intensités nominales 20 A à 50 A - Partie 001 : Spécification technique

Le présent document spécifie les disjoncteurs unipolaires compensés en température à intensité nominale de 20 A à 50 A, utilisés dans les circuits embarqués des aéronefs. Il décrit les caractéristiques d'environnement, électriques et mécaniques spécifiques, et la rigueur des essais à appliquer conformément aux méthodes d’essais de l’EN 3841-100.
Ces disjoncteurs sont destinés à être utilisés à bord des aéronefs avec une alimentation électrique conforme à l’EN 2282 (toutes catégories).

Aeronavtika - Odklopniki, enopolni, temperaturno kompenzirani, za naznačene tokove od 20 A do 50 A - 001. del: Tehnična specifikacija

Ta dokument določa enopolne temperaturno kompenzirane odklopnike z naznačenim tokom od 20 A do 50 A, ki se uporabljajo v letalskih vezjih. Opisuje posebne okoljske, električne in mehanske lastnosti ter strogost preskusov, ki se uporabljajo v skladu s preskusnimi metodami iz standarda EN 3841-100.
Ti odklopniki so namenjeni uporabi v letalskih plovilih z električno oskrbo v skladu s standardom EN 2282 (vse kategorije).

General Information

• Status: Published
• Public Enquiry End Date: 28-Oct-2020
• Publication Date: 03-Dec-2023
• ICS: 29.120.50 - Fuses and other overcurrent protection devices
• ICS: 49.060 - Aerospace electric equipment and systems
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 28-Nov-2023
• Due Date: 02-Feb-2024
• Completion Date: 04-Dec-2023
• Ref Project: EN 2794-001:2023 - Aerospace series - Circuit breakers, single-pole, temperature compensated, rated currents 20 A to 50 A - Part 001: Technical specification

Relations

• Revised: SIST EN 2794-001:2014 - Aerospace series - Circuit breakers, single-pole, temperature compensated, rated current 20 A to 50 A - Part 001: Technical specification
• Effective Date: 19-Jan-2023

Overview - EN 2794-001:2023 (Aerospace circuit breakers)

EN 2794-001:2023 is a CEN aerospace series technical specification for single‑pole, temperature‑compensated circuit breakers rated 20 A to 50 A for aircraft on‑board electrical circuits. Approved July 2023 (superseding EN 2794‑001:2014), it defines environmental, electrical and mechanical characteristics, and the required test stringency using the test methods in EN 3841‑100. These circuit breakers are intended for aircraft with electrical supplies conforming to EN 2282 (all categories).

Key topics and technical requirements

• Type and rating: Single‑pole, temperature‑compensated breakers, rated 20 A–50 A. Rating marking must appear in indelible white on the control actuator.
• Operation and mechanism: Push‑pull single push button actuator with delayed action trip‑free tripping; breaker must remain open if actuator is held during overload.
• Materials:
  • Metallic parts resistant or protected against corrosion; galvanic couples limited (≤ 0.25 V).
  • Insulation must be auto‑extinguishing/non‑flammable, not emit harmful vapours or support microbial growth.
• Environmental & performance limits:
  • Operational ambient temperature range: −55 °C to +125 °C.
  • Temperature compensation characteristics as defined in the product standard.
• Mechanical dimensions & mounting:
  • Panel cut‑out per TR 6083 C202; recommended spacing 25 mm horizontal / 40 mm vertical; panel thickness 1–3 mm.
  • Mechanical forces and torques (visual check, operational/closing/opening forces, transverse/longitudinal loads, tightening torques) referenced to EN 3841 parts with specific limits in the product standard.
• Safety features: Rating inviolability (sealed calibration), leakage creepage/clearance requirements, protection against non‑release without causing fire or heavy smoke.
• Tests & qualification: Mechanical, environmental, electrical and qualification tests per EN 3841 series; sampling, material tests, periodic checks, quality assurance, marking, packaging and storage conditions specified.

Applications and who uses it

• Aircraft OEMs, electrical system designers and integrators specifying onboard overcurrent protection.
• Avionics and electrical component manufacturers for product design, qualification and procurement.
• Maintenance organizations and regulators for component selection, airworthiness compliance and replacement parts.
• Procurement/specification teams in aerospace supply chains seeking standardized circuit breakers for 20–50 A circuits.

Related standards

• EN 3841 series - Circuit breaker test methods (including EN 3841‑100)
• EN 2282 - Aircraft electrical supply characteristics
• TR 6083 - Panel cut‑out and installation
• EN 2083, EN 2825 / EN 2826, EN 3844‑1 - Materials, burning behaviour and flammability tests

Keywords: EN 2794-001:2023, aerospace circuit breakers, temperature compensated circuit breakers, single‑pole 20 A to 50 A, EN 3841‑100, EN 2282.

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2024
Aeronavtika - Odklopniki, enopolni, temperaturno kompenzirani, za naznačene
tokove od 20 A do 50 A - 001. del: Tehnična specifikacija
Aerospace series - Circuit breakers, single-pole, temperature compensated, rated
currents 20 A to 50 A - Part 001: Technical specification
Luft- und Raumfahrt - Schutzschalter, einpolig, temperaturkompensiert, Nennströme von
20 A bis 50 A - Teil 001: Technische Lieferbedingungen
Série aérospatiale - Disjoncteurs unipolaires compensés en température, intensités
nominales 20 A à 50 A - Partie 001 : Spécification technique
Ta slovenski standard je istoveten z: EN 2794-001:2023
ICS:
29.120.50 Varovalke in druga Fuses and other overcurrent
nadtokovna zaščita protection devices
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 2794-001
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2023
EUROPÄISCHE NORM
ICS 49.060 Supersedes EN 2794-001:2014
English Version
Aerospace series - Circuit breakers, single-pole,
temperature compensated, rated currents 20 A to 50 A -
Part 001: Technical specification
Série aérospatiale - Disjoncteurs unipolaires Luft- und Raumfahrt - Schutzschalter, einpolig,
compensés en température, intensités nominales 20 A temperaturkompensiert, Nennströme von 20 A bis 50
à 50 A - Partie 001 : Spécification technique A - Teil 001: Technische Lieferbedingungen
This European Standard was approved by CEN on 23 July 2023.

CEN 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 CEN
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 CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 2794-001:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Description . 4
5 Design . 5
5.1 Materials . 5
5.1.1 Metallic materials . 5
5.1.2 Insulation materials . 5
5.2 Design . 5
5.2.1 Insulating box . 5
5.2.2 Free release mechanism . 5
5.2.3 Attachment . 5
5.2.4 Electrical connection units . 5
5.2.5 Control actuator . 5
5.2.6 Rating inviolability . 6
5.2.7 Leakage lines . 6
5.2.8 Protection against non-release . 6
6 Characteristics . 6
6.1 General characteristics . 6
6.2 Ratings . 6
6.3 Nominal voltage of operational circuits . 6
6.4 Dimensional characteristics . 7
6.5 Recommended panel mounting dimensions . 7
7 Tests . 7
7.1 Mechanical tests . 7
7.2 Environmental tests . 7
7.3 Electrical tests . 13
8 Qualification tests . 15
8.1 Sampling . 15
8.2 Material tests . 19
8.3 Periodic checks for qualification maintenance . 19
9 Quality assurance . 19
10 Marking . 19
11 Delivery conditions . 19
12 Packaging . 20
13 Storage . 20
13.1 Definition . 20
13.2 Storage conditions . 20
13.3 Storage duration . 20
Bibliography . 21

European foreword
This document (EN 2794-001:2023) has been prepared by the Aerospace and Defence Industries
Association of Europe — Standardization (ASD-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-STAN, prior to its presentation to CEN.
This document shall be given the status of a national standard, either by publication of an identical text
or by endorsement, at the latest by May 2024, and conflicting national standards shall be withdrawn at
the latest by May 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 2794-001:2014.
The main changes with respect to the previous edition are as follows:
— prEN 2794-001 (P2), 02/2012 — Editorial revision of this document: g replaced by g-PK for
n
sinusoidal and low frequencies, g replaced by Grms for random.
n
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this document: Austria, Belgium, Bulgaria, Croatia, Cyprus,
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
1 Scope
This document specifies the single-pole temperature compensated circuit breakers rated from 20 A to
50 A and used in aircraft on-board circuits. It describes specific environmental, electrical and
mechanical characteristics and the stringency of tests to be applied according to test methods of
EN 3841-100.
These circuit breakers are intended for use in aircraft with electrical supplies in accordance with
EN 2282 (all categories).
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 2083, Aerospace series — Copper or copper alloy conductors for electrical cables — Product standard
EN 2282, Aerospace series — Characteristics of aircraft electrical supplies
EN 2825, Aerospace series — Burning behaviour of non-metallic materials under the influence of
radiating heat and flames — Determination of smoke density
EN 2826, Aerospace series — Burning behaviour of non-metallic materials under the influence of
radiating heat and flames — Determination of gas components in the smoke
EN 3841-*, Aerospace series — Circuit breakers — Test methods
EN 3844-1, Aerospace series — Flammability of non-metallic materials — Part 1: Small burner test,
vertical — Determination of the vertical flame propagation
TR 6083, Aerospace series — Cut-outs for installation of electrical components
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 3841-100 apply.
ISO and IEC maintain terminology 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/
4 Description
These circuit breakers are operated by a “push-pull” type single push button (actuator) and with
delayed action “trip-free” tripping. Their function is ensured up to the short-circuit current.

Published as ASD-STAN Standard at the date of publication of this document by AeroSpace and Defence
industries Association of Europe — Standardization (ASD-STAN), https://www.asd-stan.org/.
*
All parts quoted in this document.
2)
Published as ASD-STAN Technical Report at the date of publication of this document. http://www.asd-
stan.org/.
5 Design
5.1 Materials
5.1.1 Metallic materials
All metallic parts shall be resistant to corrosion or finished against corrosion. When dissimilar materials
are in close contact, an adequate protection against corrosion shall be used so that the electromotive
force of the galvanic couple does not exceed 0,25 V.
When bimetals are used, an eventual corrosion shall not affect the good operation of the circuit breaker.
5.1.2 Insulation materials
The insulating parts shall be made of auto-extinguishing or non-flammable materials; they shall not
emit damaging or explosive vapours, even in presence of fire or internal electric arc.
They shall be insensitive to moulds and microorganisms action.
Application of any material or protective coating which might crack, break on flake shall be forbidden.
Materials which are not specified, or which are not specially described shall be as light as possible for
the requested use.
Materials shall be selected according to security criteria (toxicity, smoke density) as defined in
contractual documents.
5.2 Design
5.2.1 Insulating box
The insulating box shall integrate besides the mechanism, the connection and attachment unit.
5.2.2 Free release mechanism
Design of circuit breaker mechanism shall allow free release, i.e. the circuit breaker cuts out in case of
overload and remains cut out even if the actuator is kept by force in engaged position.
A new engagement of circuit breaker is only possible after a first total release of the control actuator.
The operation in these conditions shall not affect further performances of the circuit breaker.
5.2.3 Attachment
All visible parts shall be black-coloured and non-reflective.
5.2.4 Electrical connection units
They shall be able to receive the lugs.
5.2.5 Control actuator
In engaged position, the visible part of the control actuator shall be of the colour stated in the product
standard. In disengaged (or opened) position, the control actuator shall show a white strip.
The outer part of this actuator shall be isolated from all undervoltage parts.
The control actuator shall not stay in a transition position or give a false indication about the circuit
breaker condition. It shall not be removable.
When pushing it, power contacts of the circuit breaker engage.
When pulling it, power contacts of the circuit breaker open.
The circuit breaker rating is indicated in indelible white colour on the front part of the control actuator.
The product standard gives the digits positioning.
5.2.6 Rating inviolability
The circuit breaker shall be designed in such a way that the calibration unit cannot be reached without
breaking a sealing.
5.2.7 Leakage lines
The leakage lines and the minimal space to be foreseen between the undervoltage parts and any other
part of the circuit breaker made of non-insulating material, as well as between the undervoltage parts of
opposite polarity, shall be sufficient to avoid any default or arcing in all uses and climatic conditions.
5.2.8 Protection against non-release
Electrical overload happening on a circuit breaker locked in its engaged position (sticked contacts or
non-operating release mechanism), shall cause the opening
...