IEC 60079-35-2:2011

Overview

IEC 60079-35-2:2011 is an international standard published by the International Electrotechnical Commission (IEC) that specifies performance and safety requirements for caplights used in mines susceptible to firedamp. Firedamp, a hazardous explosive atmosphere primarily composed of methane, presents significant safety risks in mining environments. This standard addresses performance features not covered in its companion document IEC 60079-35-1, particularly focusing on light output, reliability, ergonomics, and user safety to enhance working conditions for miners.

This edition, published in 2011, is a full technical revision replacing the earlier IEC 62013-2 (2005). It incorporates advancements in caplight technologies such as LED light sources and improves linkage with Part 1 of the standard by making cross-referencing mandatory. The update aligns this standard with the broader IEC 60079 series addressing equipment for explosive atmospheres.

Key Topics

Light Output Requirements

• Multiple Light Sources: Caplights must have at least two light sources, with one designated as the main source meeting performance criteria. A single non-filament source is permitted if it satisfies lamp life requirements.
• Beam Orientation: The caplight’s main beam must point downward at 10° ± 5° to optimize miner visibility without glare.
• Illumination Intensity: The standard requires a minimum luminous intensity cone of 1 cd (lux at 1 m) throughout the useful working period, with a maximum intensity minimum of 1,500 cd.
• Focus: The main light source must produce a focused light pattern free of distortion.
• Chromaticity: For LED or other non-filament light sources, the correlated color temperature (CCT) should be above 5,000 K with a color rendering index (CRI) greater than 70, unless otherwise specified.

Reliability and Durability

• Lamp and Battery Life: Specifies minimum lamp life for filament sources and battery charge/discharge cycles. Manufacturers must define the caplight’s useful working period based on current draw and luminous intensity maintenance.
• Physical Durability: Components such as fasteners and connectors must resist abrasion and maintain operability after mechanical stress testing.
• Maintainability: Caplights must be easy to operate and maintain, with secure headpiece attachment to avoid accidental detachment underground.

Ergonomics and Safety

• Weight and Comfort: Mass of the caplight should be optimized for lasting comfort during extended underground use.
• Ease of Use: Controls and operational mechanisms are designed for straightforward use by miners wearing gloves or in wet conditions.
• Instructions and Marking: Clear manufacturer instructions and marking requirements ensure correct use, maintenance, and routine user testing.

Applications

IEC 60079-35-2:2011 is critical for manufacturers, designers, and users of caplights in mining environments where explosive atmospheres are present, specifically those susceptible to the presence of firedamp. These caplights provide safe, reliable, and effective lighting for miners, reducing the risk of ignition of explosive gases while improving visibility and safety in hazardous conditions. The standard also supports mining operations in non-gassy environments when safety agreements are reached between suppliers and users.

Industries and sectors benefitting from this standard include:

• Underground coal and mineral mining
• Safety equipment manufacturers specializing in mining lighting solutions
• Mining safety regulatory and compliance authorities
• Equipment testing and certification bodies

Related Standards

• IEC 60079-35-1: Caplights for use in mines susceptible to firedamp - General requirements covering construction and explosion risk testing.
• IEC 60983: Specifies requirements for miniature filament lamps used in caplights.
• IEC 60050-845: International Electrotechnical Vocabulary for lighting terms ensuring consistent terminology.
• ISO 80000-1: General quantities and units relevant for defining performance metrics.
• IEC 60079 Series: Broad suite of standards addressing equipment and protective systems within explosive atmospheres for varied industrial applications.

Keywords: IEC 60079-35-2, caplights, mining safety equipment, explosive atmospheres, firedamp, LED caplight performance, mining illumination standards, caplight reliability, mining equipment ergonomics, IEC mining safety standards, underground mining lighting