Answer to Question #45398 in Engineering for Zeph

Question

Electric lighting is often overlooked as a potential source of ignition. List factors that might lead to a lighting fittings becoming an ignition source

Answer 1

The biggest single risk that lighting products have is that of heat generation and the inherent risk of fire. This is particularly the case with the smaller lighting fittings that house the popular extra low voltage' reflector type lamps, or their mains voltage equivalents.
The main heat generation risk is that many lighting products are often relatively small and compact, and thus often specified to be installed in very tight and small spaces or voids. Very few people including lighting experts do not seem to appreciate the high temperatures that these lighting products can generate.
High temperature heat sources like lighting fittings may pose a risk of ignition to combustible materials that may come in close proximity to the same, or even the material upon which the lighting fittings are mounted.
The risk may be further compounded by the fact that some lighting products or. lamp types are designed to dissipate their heat out of the back of the product or lamp (typically ‘dichroic’ type lamps) whilst others are designed to direct their heat forward (typically ’aluminium reflector type lamp).
Another risk is that to an untrained person during maintenance, many lamp types look the same, and have similar interchangeable bases and lamp caps, and incorrect lamp types may be fitted.
Designers, electricians and contractors when specifying or installing lighting products or replacing lamps need to carefully consider their selection and adequately address the design issues and potential fire risks of their designs and installations.
Typical examples of risks to be considered;
• Soft furnishings, curtains, etc. placed close to lighting products.
• Combustible dust/debris building up behind lighting products.
• Lighting products in voids, roof space, or attic areas must be kept away from combustible materials.
Additional heat protection measures may need to be considered if there is any risk of ignition from the heat generated by the lighting products to be installed.