Considerations regarding the main differences between flameproof electric motors, designed for explosion Group IIC, compared to explosion Group IIB, when testing in explosive mixtures

The flameproof enclosure type of protection is still one the safest because it based on a very simple and, therefore, unlikely fallible technology. If an explosive atmosphere penetrates producing trigger, explosion occurs, but remains confined within enclosure. EN 60079-1 standard, states that flanged flame paths are allowed in presence gases and vapours Group IIB, cannot be used with IIC. Also, transmission tests for IIB equipment carried out at atmospheric pressure, whereas IIC they conducted (depending testing method applied) higher initial pressure. purpose paper to perform thorough study upon differences between electric motors IIC, compared vapours, terms conditions required by standard how group influences maximum pressures pressure development, when tested mixtures vapours. this assist manufacturers designing satisfy requirements specific either or applications order smooth path certification.