EN 4728:2015

Overview

EN 4728:2015 is a European Standard developed by CEN that specifies the characteristics of dummy circuit breakers used in aerospace applications. These dummy circuit breakers, available in single and three-pole configurations, are designed for provisional connection of cables in aircraft on-board circuits. Importantly, they contain no electrical connections between terminals, serving purely as mechanical placeholders in wiring installations.

The standard ensures consistent design, dimensions, material, and marking requirements for these essential aerospace components, enabling compatibility and safety in aircraft electrical systems during installation and maintenance phases.

Key Topics

• Scope and Purpose
  EN 4728:2015 applies to dummy circuit breakers used for temporarily connecting cables aboard aircraft without providing actual electrical continuity.

• Design and Dimensions
  The standard covers detailed dimensional codes, model variations (Model Code A with control button, Model Code B without), and mass specifications to ensure physical compatibility with corresponding functional circuit breakers.

• Material and Mechanical Properties
  Specifications mandate materials and surface treatments consistent with aerospace requirements. Mechanical robustness includes resistance to vibration, shocks, and environmental factors like humidity and corrosion, reflecting actual operating conditions.

• Marking and Identification
  Products must carry markings including standard designation, manufacturing date, manufacturer identification, pin terminal info, and part numbers for traceability and quality assurance.

• Technical Specifications and Compliance
  The dummy circuit breakers must comply with corresponding technical specifications linked to functional circuit breakers as referenced in related EN standards such as EN 2995 and EN 3661 series.

Applications

• Aircraft On-Board Circuit Installation
  These dummy circuit breakers are critical for temporary wiring setups during aircraft assembly or maintenance, allowing technicians to provisionally interconnect cables while preventing electrical flow and ensuring safety.

• Testing and Validation
  Used during wiring system validation phases to simulate circuit breaker presence, facilitating system checks without risking electrical shorts or unintended operation.

• Maintenance and Spare Parts
  Serve as placeholder devices in aircraft electrical panels, maintaining wire routing integrity and simplifying troubleshooting or component replacement without affecting actual electrical circuits.

• Training and Demonstration
  Useful in aerospace training environments to represent circuit breakers safely, enabling hands-on learning without live electrical risks.

Related Standards

• EN 2995 Series – Technical specifications and product standards for single-pole temperature-compensated circuit breakers with rated currents from 1 A to 25 A.

• EN 2996 Series – Related standards covering three-pole circuit breakers for similar ratings as EN 2995.

• EN 3661 and EN 3662 Series – Address single-pole and three-pole circuit breakers with rated currents from 20 A to 50 A, including versions with polarized signal contacts.

• EN 6113 – Aerospace standard for circuit breaker connecting and attachment hardware, referenced for delivery hardware kits in EN 4728.

Practical Value

EN 4728:2015 ensures that dummy circuit breakers used in aerospace applications meet stringent mechanical and environmental requirements, enabling seamless integration with aircraft electrical systems during installation and testing phases. By standardizing dimensions, material properties, and marking conventions, this standard supports safety, interoperability, and traceability, which are vital in aerospace manufacturing and maintenance.

Adherence to EN 4728 minimizes the risk of installation errors, protects sensitive equipment during wiring deployment, and facilitates efficient aircraft wiring system commissioning. Engineers, manufacturers, maintenance personnel, and procurement specialists benefit from the clear guidance provided, advancing reliability and safety in aerospace electrical infrastructure.

Keywords: EN 4728:2015, aerospace dummy circuit breakers, single-pole circuit breakers, three-pole circuit breakers, aircraft electrical systems, aviation wiring standards, CEN aerospace standards, provisional cable connection, circuit breaker placeholders, aerospace electrical safety, circuit breaker dimensions, aviation maintenance standards.