No abstract

Design reliable and safe LED (light emitting diode) lighting equipment for potentially explosive atmospheres should require knowledge about the possible failure modes of LED sources. Nowadays, LED technology potential is not adequately considered by IECEx (International Electrotechnical Commission system for certification to standards relating to equipment for use in explosive atmospheres) yet. Standards only consider LEDs adequate for Zone 1 when luminary is realized by the Ex-d protection strategy, or if a big limitation in terms of power is guarantee, for Ex-i mode. In particular, Ex-d LED luminaries are obtained by using heavy, thick and expensive flameproof enclosures, entrusting safety only to the mechanical strength of the case. Luminous efficiency's also reduced since the glass used is very thick (10% reduction of approximately every 10 mm of thickness of the glass). The paper shows a study about different possible causes of LED failure and their implication with explosive atmospheres, investigating whether LED technology can be used safely with other safety strategy like Ex-e, which can guarantee better performance and less cost.