prEN IEC 60079-7:2023

This part of IEC 60079 specifies the requirements for the design, construction, testing and marking of electrical Ex Equipment and Ex Components with Type of Protection increased safety “e” intended for use in explosive gas atmospheres.
Electrical Ex Equipment and Ex Components of Type of Protection increased safety “e” are either:
a) Level of Protection “eb” (EPL “Mb” or “Gb”); or
b) Level of Protection “ec” (EPL “Gc”)
Level of Protection “eb” applies to Ex Equipment or Ex Components, including their connections, conductors, windings, lamps, and batteries; but not including semiconductor devices or electrolytic capacitors.
NOTE 1 The fundamental basis of “eb” is limitation of temperature, and reduced likelihood of insulation failure resulting in an arc or spark. Expected malfunctions of electronic components, such as semiconductor devices or electrolytic capacitors, can result in a failure producing excessive temperatures, or arcs and sparks.
Level of Protection “ec” applies to Ex Equipment or Ex Components, including their connections, conductors, windings, lamps, and batteries; and also including semiconductor devices and electrolytic capacitors.
NOTE 2 The use of electronic components, such as semiconductor devices or electrolytic capacitors, is permitted in
Level of Protection “ec” as these are evaluated under both normal conditions and regular expected occurrences, and are not likely to result in excessive temperatures or arcs and sparks. As the requirements for separation distances are not applied to the internal construction, commercially available electronic components are generally suitable if the external separation distances comply.
The requirements of this standard apply to both Levels of Protection unless otherwise stated.