In accordance with IEC Standard 60079-0 (2007), devices for potentially explosive areas are divided into three protection levels (for devices in mine workings susceptible to firedamp, two protection levels are laid down):
- EPL Ga or Da
device with "very high" protection level for use in potentially explosive areas, in the normal operation of which, foreseeable or infrequent faults/malfunctions represent no danger of ignition.
- EPL Gb or Db
device with "high" protection level for use in potentially explosive areas, in the normal operation of which, foreseeable or infrequent faults/malfunctions represent no danger of ignition.
- EPL Gc or Dc
device with "increased" protection level for use in potentially explosive areas, in the normal operation of which, no danger of ignition exists and which is equipped with various additional protective measures which guarantee, in the event of commonly foreseeable faults in the device, that no danger of ignition exists.
The letters "G" and "D" determine whether the device is suitable for potentially explosive areas due to gas (G) or for areas with combustible dust (D).
Devices for mine workings susceptible to firedamp:
- EPL Ma
device with "very high" protection level for installation in mine workings susceptible to firedamp which guarantees the necessary degree of safety, with which in normal operation, foreseeable or infrequent faults/malfunctions represent no danger of ignition, even if the device is still in operation when the gas escape occurs.
- EPL Mb
device with "high" protection level for installation in mine workings susceptible to firedamp which guarantees the necessary degree of safety, with which in normal operation, foreseeable or infrequent faults/malfunctions represent no danger of ignition in the time between when the gas escape occurs and the device is switched off.
