Aspects regarding the surface temperature for luminaires used in potentially explosive atmosphere

Assessment for certification purposes of explosion-proof electrical equipment is considerd to be very important taking into account the risk of explosion that needs to be maintained at a safe level in order to provide both safety and health of workers and to prevent the damage over property and the environment; and also free movement of goods meeting the EU essential safety requirements. Even if luminaires intended to be used in explosive atmospheres are designed and built using some of specific principles as those used for luminaires intndended to be used in normal environment, they also present other specific characteristics related to their area of use. Therefore, specific requirements and tests are needed to be taken into account in this case. The surface temperature is a very important component on which the explosion protection depends. The surface temperature is the highest temperature reached in running conditions, under the most unfavorable circumstances by any component of the electrical luminaire. The maximum surface temperature may appear on an internal component or on the outer surface of the equipments which operate in explosive atmospheres generated by gases, that can occur in technical installations endangered by the presence of explosive atmospheres. In the case of electrical equipment used in (potentially) explosive atmospheres, in order to provide explosion protection, it is essential that the tests carried out on the equipment during the certification process are performed in accordance with the requirements of the standards referring to the protection types used in the construction of the equipment.