Considerations regarding test methods against dust and water ingress protection for Ex equipment

Abstract

The explosion danger in all industries where explosive atmospheres generated by the mixture of combustible dusts or flammable gases with air may form, must be treated as a major hazard, as the explosions that may occur can seriously affect both health and safety people, as well as the environment. It is therefore necessary to assess the explosion risk and to establish appropriate measures to reduce it to acceptable levels in accordance with the requirements of the European Directives. An essential element in the assessment of the explosion risk for electrical and non-electrical equipment intended for use in potentially explosive atmospheres is the way in which an appropriate normal degree of protection is provided through the equipment housing (protection against touching of dangerous parts inside the equipment housing and protection against the ingress of dust and water inside it). The aim of the paper is to highlight compliance with the requirements of the ATEX Directive, given that this protection is a basic requirement for explosion protection and to present the important elements to be considered for the assessment of the normal degree of protection and the development of harmonized test methods with the requirements of European standards.

Quality assurance issues for normal grade testing protection provided by equipment housings Ex

“…According to the ATEx Directive 2014/34 / EU, taken over in the Romanian legislation by GD 245/2016, the technical equipment intended for use in areas with danger of potentially explosive atmospheres is divided into two groups and three categories. The appropriate procedure for assessing the conformity of the product by an accredited body shall be chosen, after the manufacturer has decided, to which groups and categories the equipment belongs, depending on the level of protection required for the chosen destination [2][3][4].…”

“…In these situations, one of the characteristic figures must be replaced by the letter "X", the normal degree of protection of a technical equipment can be expressed for example, in the following form: IP 5X, IP X7, IP 6X, IP X6 / X8. By combining the two characteristic digits (the first and the second characteristic digit), in practice, technical equipment with the following normal degrees of protection, shown in Table 2, can be made [2,3,6,7].…”

“…To perform the tests for all 12 housings, follow the steps in the flow chart shown in Fig. 4 [3,7,13,14]. The expected value corresponds directly to the test result in terms of passed / failed assessments, performed after each test, the difference being the estimation of the absolute differences between the assigned value and the participant's result.…”