Guide To: UNECE R5 - Sealed Beam headlamps

UN ECE Regulation No. 5 establishes the uniform provisions concerning the approval of sealed-beam headlamps for power-driven vehicles. These headlamps are designed to emit a European asymmetrical passing beam, a driving beam, or both. Sealed-beam units (SB units) are integral lighting components that are permanently sealed during manufacture and cannot be dismantled without rendering them unusable.

Scope of the Regulation

UN ECE R5 applies to:

• Sealed-beam headlamps (SB units) for motor vehicles, primarily for vehicles in category T, which includes agricultural tractors, forest tractors, and other slow-moving vehicles.

Key Features of UN ECE R5

1. Sealed-Beam (SB) Units:

   • Sealed-beam headlamps (SB units) consist of a reflector system, lens system, and electrical light sources, all of which are permanently sealed together. These units cannot be disassembled or repaired without destroying the unit.

2. Types of SB Units:

   • SB units differ in various characteristics such as trade name, optical system, voltage, wattage, filament shape, and beam type (passing or driving beam).
   • The regulation allows for SB units that can be adapted for both right-hand and left-hand traffic, with distinct markings indicating the appropriate setting for each traffic system.

3. Approval Process:

   • Manufacturers must apply for type approval, providing technical details, drawings, and samples of the SB units for testing. The units must meet specific standards for light output, beam shape, and durability.
   • Upon meeting the requirements, an approval mark is assigned, which includes the approval number and additional symbols denoting specific beam types and traffic settings.

4. Illumination and Light Intensity:

   • The regulation defines strict photometric standards for the passing beam and driving beam to ensure sufficient illumination without causing discomfort or dazzle to other road users. The passing beam must produce a sharp cut-off line, helping with alignment and preventing glare.
   • SB units are tested at a distance of 25 meters on a vertical screen, and specific illumination levels must be achieved in defined zones.

5. Colour of Light:

   • SB units approved under this regulation must emit white light, in accordance with the colorimetric standards defined by UN ECE R48.

6. Durability and Environmental Testing:

   • SB units are tested for durability under normal vehicle operating conditions, including exposure to vibration and environmental elements. If plastic lenses are used, additional tests are conducted to ensure the lenses remain effective and durable.

Conclusion

UN ECE R5 ensures that sealed-beam headlamps meet stringent safety, performance, and durability standards for vehicles, particularly for those in category T. By setting specific guidelines for beam patterns, light intensity, and durability, this regulation helps improve road safety by ensuring consistent and reliable vehicle lighting.