Luminaire fasteners, corrosion protection

Luminaire suspension devices must not exhibit any hazardous changes when burdened with loads of five times the luminaire's mass (or a minimum of 10 kg). This applies to fixing accessories offered by luminaire manufacturers according to device regulation EN 60598 as well as for fixing equipment provided on-site according to installation regulation HD 60364-5-559.

In damp or wet rooms as well as in outdoor areas, e.g. under projecting roofs, supporting elements such as suspended ceilings and luminaires and their fixing equipment must be sufficiently protected against corrosion. In most cases, “normal” stainless steel or sufficiently galvanised materials are sufficient.

Figure 2.54: Corrosion

Humid, warm and chloric air, e.g. at insufficiently ventilated indoor swimming pools can form acidic and saliferous films on fixing components, which, due to complicated access, are not always rinsed off sufficiently during cleaning and therefore become more and more concentrated. This can cause long-term corrosion. This particularly affects suspension equipment with small diameters and equipment under constant mechanical stress (traction, pressure). In such cases, long-term corrosion effects due to the electrochemical series (electrolyte formation) between less compatible, conducting construction materials must be given special consideration. In extreme environmental conditions, it may be necessary to use higher-quality metals or appropriate plastic suspension equipment. For example, in outdoor lighting, where similar long-term corrosion can occur, wire suspensions made of glass fibre-reinforced polyester plastic are used for luminaires suspended between buildings to counteract this issue.

Competent material testing institutions therefore recommend reinforced, galvanised ceiling hooks (e.g. 8 mm instead of 6 mm hooks) for corrosive atmospheres.