SIST EN 3841-307:2005

Aerospace series - Circuit breakers - Test methods - Part 307: Performance with a locked tripping system

This standard specifies a method of verifying the performance of circuit breakers with a locked tripping system.
It shall be used together with EN 3841-100.
The test is intended to estimate the consequences of a trip failure in the case of a short-circuit.

Luft- und Raumfahrt - Schutzschalter - Prüfverfahren - Teil 307: Verhalten mit blockiertem Auslösesystem

Série aérospatiale - Disjoncteurs - Méthodes d'essais - Partie 307 : Comportement avec mécanisme bloqué

Aeronavtika - Odklopniki - 307. del: Lastnosti pri blokiranem prožilnem sistemu

General Information

• Status: Published
• Publication Date: 31-Mar-2005
• ICS: 49.060 - Aerospace electric equipment and systems
• Technical Committee: SS SPL - Technical Board for the general field
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Apr-2005
• Due Date: 01-Apr-2005
• Completion Date: 01-Apr-2005
• Ref Project: EN 3841-307:2004 - Aerospace series - Circuit breakers - Test methods - Part 307: Performance with a locked tripping system

Overview

EN 3841-307:2004 - “Aerospace series - Circuit breakers - Test methods - Part 307: Performance with a locked tripping system” is a CEN-adopted aerospace test standard for verifying the behaviour of circuit breakers when their tripping mechanism is locked. The test method is intended to estimate the consequences of a trip failure under short-circuit conditions and is to be used together with EN 3841-100 (general test methods for aerospace circuit breakers).

Key topics and technical requirements

• Scope: Defines a method to verify performance of circuit breakers with a locked tripping system to simulate a failed trip (e.g., welded contacts).
• Relationship: Must be applied in conjunction with EN 3841-100 (general mounting, instrumentation and test conditions).
• Locked mechanism simulation: The tripping mechanism is mechanically locked so the breaker cannot open by its normal actuation - used to simulate contact welding without directly affecting the bimetal.
• Poles under test:
  • Single-pole configuration: test circuits defined for both d.c. and a.c. (see Figure 1 in the standard).
  • Three-pole circuit breakers: only one pole is tested while the other poles remain unloaded (see Figure 2).
• Test mounting and circuit: Mounting and wiring follow EN 3841-100 and the applicable technical specification. Test circuits include provision for inductance, loading resistor, measurement shunt/converter, fuses and the specified test voltage.
• Temperature conditioning: Specimens are placed in an oven at 90 °C for 2 hours (no-load), then tested within 5 minutes of removal.
• Acceptance criteria: The breaker may open only by destructive means but must not burst, produce flaming or thick smoke. The duration limits are those specified in the applicable technical specification.

Applications and users

• Who uses it: Aerospace manufacturers, design and test engineers, component qualification labs, certification bodies and maintenance organizations involved in electrical power systems for aircraft and aerospace platforms.
• Practical value:
  • Evaluates risk and behaviour when a circuit breaker fails to trip during a short-circuit (safety and reliability analysis).
  • Supports component qualification, type approval and verification of robustness under fault conditions.
  • Informs system-level hazard assessments and selection of protective devices in aircraft electrical systems.

Related standards

• EN 3841-100 - Aerospace series: Circuit breakers - Test methods - Part 100: General (normative reference).
• Document prepared under AECMA-STAN and adopted by CEN (EN 3841-307:2004).

Keywords: aerospace circuit breakers, locked tripping system, test methods, EN 3841-307:2004, short-circuit performance, circuit breaker verification, CEN aerospace standards.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2005
Aeronavtika - Odklopniki - 307. del: Lastnosti pri blokiranem prožilnem sistemu
Aerospace series - Circuit breakers - Test methods - Part 307: Performance with a
locked tripping system
Luft- und Raumfahrt - Schutzschalter - Prüfverfahren - Teil 307: Verhalten mit
blockiertem Auslösesystem
Série aérospatiale - Disjoncteurs - Méthodes d'essais - Partie 307 : Comportement avec
mécanisme bloqué
Ta slovenski standard je istoveten z: EN 3841-307:2004
ICS:
49.060 /HWDOVNDLQYHVROMVND Aerospace electric
HOHNWULþQDRSUHPDLQVLVWHPL equipment and systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 3841-307
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2004
ICS 49.060
English version
Aerospace series - Circuit breakers - Test methods - Part 307:
Performance with a locked tripping system
Série aérospatiale - Disjoncteurs - Méthodes d'essais - Luft- und Raumfahrt - Schutzschalter - Prüfverfahren - Teil
Partie 307 : Comportement avec mécanisme bloqué 307: Verhalten mit blockiertem Auslösesystem
This European Standard was approved by CEN on 10 September 2004.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3841-307:2004: E
worldwide for CEN national Members.

Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Method .4
3.1 General conditions .4
3.2 Test mounting .4
3.3 Test circuit.4
3.4 Procedure
...