Protection Levels2019-04-08T04:07:15+00:00

Equipment Protection Levels

The Level of Protection assigned to equipment is based on its likelihood of becoming a source of ignition and is often in line with Ex Zones.

The Equipment Protection Level (EPL) is based on a grading.  In some case equipment may be assembled with devices with varying EPLs and this will impact the final rating and Ex Code. One example might be a higher rated device (e.g. Ma), however housed within a lower rated enclosure (e.g. Mb), resulting in a maximum Mb rating.

Equipment Protection Levels

Group, Zone and suitable Equipment Protection Level

GROUP IGROUP IIGROUP III
Zone 0 - EPL MaZone 0 - EPL GaZone 20 - EPL Da
Zone 1 - EPL Ma, MbZone 1 - EPL Ga, GbZone 21 - EPL Da, Db
Zone 2 - EPL Ga, Gb, GcZone 22 - EPL Da, Db, Dc

EPL Ma

Equipment for installation in a mine susceptible to firedamp*, having a “very high” Level of Protection, which has sufficient security that it is unlikely to become an ignition source in normal operation, during expected malfunctions or during rare malfunctions, and may be left energized even in the presence of an outbreak of gas.

*Firedamp is defined as the gas typically formed in coal mines. This gas is typically methane but might also contain other flammable and explosive gasses.

EPL Mb

Equipment for installation in a mine susceptible to firedamp, having a “high” Level of Protection, which has sufficient security that it is unlikely to become a source of ignition in normal operation or during expected malfunctions in the time span between there being an outbreak of gas and the equipment being de-energized.

EPL Ga

Equipment suitable to be installed in Group II explosive gas atmospheres, having a “very high” Level of Protection, which is not a source of ignition in normal operation, during expected malfunctions or during rare malfunctions.

EPL Gb

Equipment suitable to be installed in Group II explosive gas atmospheres, having a “high” Level of Protection. This equipment is not a source of ignition in normal operation or during expected malfunctions.

EPL Gc

Equipment suitable to be installed in Group II explosive gas atmospheres, having an “enhanced” Level of Protection. The equipment is not a source of ignition in normal operation and which may have some additional protection to ensure that it remains inactive as an ignition source in the case of regular expected occurrences (for example failure of a lamp).

EPL Da

Equipment suitable to be installed in explosive dust atmospheres, having a “very high” Level of Protection, which is not a source of ignition in normal operation, during expected malfunctions, or during rare malfunctions.

EPL Db

Equipment suitable to be installed in explosive dust atmospheres, having a “high” Level of Protection, which is not a source of ignition in normal operation or during expected malfunctions.

EPL Dc

Equipment suitable to be installed in explosive dust atmospheres, having an “enhanced” level of protection, which is not a source of ignition in normal operation and which may have some additional protection to ensure that it remains inactive as an ignition source in the case of regular expected occurrences (for example failure of a lamp).