oSIST prEN 2794-004:2026
(Main)Aerospace series - Circuit breakers, single-pole, temperature compensated, rated currents 20 A to 60 A - Part 004: UNC thread terminals - Product standard
General Information
- Abstract
This document specifies the characteristics of single-pole circuit breakers, temperature compensated with a rated current from 20 A to 25 A, used in aircraft on-board circuits at a temperature between −55 °C and 125 °C and at an altitude of 15 000 m max.
These circuit breakers are operated by a push-pull type single push button (actuator), with delayed action “trip-free” tripping.
They will continue to function up to the short-circuit current.
- Status
- Not Published
- Public Enquiry End Date
- 30-Oct-2026
- Technical Committee
- I13 - Imaginarni 13
- Current Stage
- 4020 - Public enquire (PE) (Adopted Project)
- Start Date
- 20-Aug-2026
- Due Date
- 07-Jan-2027
Overview
oSIST prEN 2794-004:2026 defines the product standard for aerospace single-pole, temperature-compensated circuit breakers with rated currents from 20 A to 60 A, specifically focusing on models with UNC thread terminals. Developed by the Slovenian Institute for Standardization (SIST) and in alignment with the European Committee for Standardization (CEN), this draft standard applies to circuit breakers used in aircraft on-board electrical circuits. These devices are engineered to operate at extreme temperatures from −55 °C to 125 °C and at altitudes up to 15,000 meters, ensuring safety and reliability under harsh aerospace conditions.
The standard supersedes EN 2794-004:2014 and introduces updated requirements regarding short-circuit values, mass, actuator dimensions, and performance thresholds. oSIST prEN 2794-004:2026 is a key reference for product conformity, quality assurance, and the design of critical electrical components in the aerospace sector.
Key Topics
- Product Characteristics: Specifies the material, mechanical, and environmental properties necessary for aerospace circuit breakers, including push-pull (trip-free) actuators and delayed tripping functionality.
- Electrical Performance: Covers key electrical ratings such as nominal voltages (28 V DC and 115 V AC, 360 Hz to 800 Hz), current ratings (20–60 A), voltage drops, tripping thresholds, overload and short-circuit capabilities.
- Mechanical Endurance: Details the endurance under vibration, shock, mechanical cycling, and varying environmental influences like humidity and corrosion.
- UNC Thread Terminals: Focuses on the design and dimensions for compatibility with UNC threaded connections, ensuring secure installation and standardized interface.
- Installation Requirements: Outlines recommended tightening torques, fastener compatibility according to EN 6113, and panel cut-out dimensions per EN 2794-001.
- Identification and Marking: Prescribes marking protocols for traceability, including manufacturer, date code, electrical characteristics, and hardware designation.
- Compliance and Safety: Ensures devices comply with stringent safety requirements applicable to aircraft environments, providing reliable protection for critical electrical circuits.
Applications
- Aircraft On-Board Circuits: Used in primary and secondary electrical distribution systems across all types of aircraft, ensuring overload and short-circuit protection in vital circuits.
- High-Reliability Environments: Suited for environments with extreme temperature variations and high altitude, such as military and commercial aviation.
- OEM and Maintenance: Supports aerospace manufacturers and maintenance organizations in equipment specification, replacement, and certification processes by providing unified product requirements.
- Panel Integration: Designed for straightforward mounting and integration into standardized aircraft electrical panels using UNC thread terminals, simplifying product selection and installation.
Related Standards
- EN 2350: Provides general technical and performance requirements for aerospace circuit breakers.
- EN 2794-001: Establishes the technical specifications for temperature-compensated single-pole circuit breakers with rated currents from 20 A to 50 A, serving as the base standard.
- EN 3841-305: Addresses test methods for circuit breakers, including short-circuit performance.
- EN 6113: Specifies the requirements for associated connecting and attaching hardware, ensuring compatibility and reliability.
- SAE-AMS-STD-595: Color standards relevant for actuator identification and aerospace procurement.
- TR 6083: Details cut-outs for the installation of electrical components in aerospace systems.
For organizations involved in the production, integration, or certification of aerospace electrical systems, oSIST prEN 2794-004:2026 is an essential standard ensuring conformity, interoperability, and operational safety for single-pole circuit breakers with UNC thread terminals. Following this product standard helps ensure mission-critical circuits remain protected and aircraft systems operate reliably under the most demanding conditions.
Relations
- Effective Date
- 08-Jan-2025
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Frequently Asked Questions
oSIST prEN 2794-004:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Aerospace series - Circuit breakers, single-pole, temperature compensated, rated currents 20 A to 60 A - Part 004: UNC thread terminals - Product standard". This standard covers: This document specifies the characteristics of single-pole circuit breakers, temperature compensated with a rated current from 20 A to 25 A, used in aircraft on-board circuits at a temperature between −55 °C and 125 °C and at an altitude of 15 000 m max. These circuit breakers are operated by a push-pull type single push button (actuator), with delayed action “trip-free” tripping. They will continue to function up to the short-circuit current.
This document specifies the characteristics of single-pole circuit breakers, temperature compensated with a rated current from 20 A to 25 A, used in aircraft on-board circuits at a temperature between −55 °C and 125 °C and at an altitude of 15 000 m max. These circuit breakers are operated by a push-pull type single push button (actuator), with delayed action “trip-free” tripping. They will continue to function up to the short-circuit current.
oSIST prEN 2794-004:2026 is classified under the following ICS (International Classification for Standards) categories: 49.060 - Aerospace electric equipment and systems. The ICS classification helps identify the subject area and facilitates finding related standards.
oSIST prEN 2794-004:2026 has the following relationships with other standards: It is inter standard links to SIST EN 2794-004:2014. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
oSIST prEN 2794-004:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2026
Aeronavtika - Odklopniki, enopolni, temperaturno kompenzirani, naznačeni tok od
20 A do 50 A - 004. del: Navojni priključki UNC - Standard za proizvod
Aerospace series - Circuit breakers, single-pole, temperature compensated, rated
currents 20 A to 60 A - Part 004: UNC thread terminals - Product standard
Luft- und Raumfahrt - Schutzschalter, einpolig, temperaturkompensiert, Nennströme von
20A bis 50A - Teil004: UNC-Klemmengewinde - Produktnorm
Série aérospatiale - Disjoncteurs unipolaires compensés en température, intensités
nominales 20 A à 50 A - Partie 004 : Bornes à filetage UNC - Norme de produit
Ta slovenski standard je istoveten z: prEN 2794-004
ICS:
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.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2026
ICS 49.060 Will supersede EN 2794-004:2014
English Version
Aerospace series - Circuit breakers, single-pole,
temperature compensated, rated currents 20 A to 60 A -
Part 004: UNC thread terminals - Product standard
Série aérospatiale - Disjoncteurs unipolaires Luft- und Raumfahrt- Schutzschalter, einpolig,
compensés en température, intensités nominales 20 A temperaturkompensiert, Nennströme von 20A bis 50A-
à 50 A - Partie 004 : Bornes à filetage UNC - Norme de Teil004: UNC-Klemmengewinde- Produktnorm
produit
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-
STAN.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 2794-004:2026 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Dimensions and mass . 4
4.1 Dimensional characteristics . 4
4.2 Electrical diagram . 6
4.3 Mass . 6
4.4 Panel cut-out . 6
5 Characteristics . 6
5.1 Material, surface treatment . 6
5.2 Mechanical characteristics . 6
5.2.1 Fasteners . 6
5.2.2 Recommended tightening torque of attaching nut for installation . 6
5.2.3 Recommended tightening torque of connection hardware for installation . 6
5.2.4 Resistance to vibrations . 7
5.2.5 Resistance to shocks . 7
5.2.6 Mechanical endurance . 7
5.3 Environment characteristics . 7
5.3.1 Humidity . 7
5.3.2 Corrosion . 7
5.3.3 Contaminating liquids . 7
5.3.4 Overvoltage caused by lightning . 7
5.4 Electrical characteristics . 7
5.4.1 Nominal voltage of operational circuits . 7
5.4.2 Voltage drop at Ι . 8
n
5.4.3 Minimum and maximum tripping thresholds . 8
5.4.4 Overload trip . 8
5.4.5 Short-circuit values . 8
5.4.6 No-Load and load endurance . 9
5.4.7 Dielectric rigidity . 9
5.4.8 Insulation resistance . 10
6 Designation . 10
7 Rated current code . 10
8 Delivery hardware code . 11
9 Marking . 11
10 Technical specification . 11
Bibliography . 12
European foreword
This document (prEN 2794-004:2026) has been prepared by 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 pr
...