This paper aims to carry out an analysis of the way in which the turbulence of the testing explosive mixture, turbulence induced by the high speed rotation movement of the shaft of the motor, as well as the rotation of the interior cooling fan, influences the maximum explosion pressures recorded, when carrying out the type tests of electrical rotating machines, when running. The paper also presents the most important results obtained in the specific laboratory of INSEMEX, during a research project carried out recently. Even if electric motors for environments with explosion hazards are designed and manufactured following the same principles as the ones used for other electric machinery, they have certain particularities related to their field of use. From here the required type of protection is resolved, with a series of restrictions imposed to electric motor projects [3]. As widely known, in case of flameproof electric motors as well as in case of most of the technical equipment in general, design and manufacture exceeded long time ago the stage when the manufacturers used to apply their own design methods.