Generally, Ex d equipment will have a level of production “db” (EPL: Mb or Gb).
This means that this equipment can be used in locations requiring EPL Gb or Gc, as indicated on the area classification drawing (in which case a risk assessment, taking into account the possible consequences of an explosion, will have been conducted).
If there are no specified EPL requirements, the equipment may be used in Zones 1 or 2
The equipment marking will include the gas subdivision (IIA, IIB or IIC), indicating the gas hazards in which it may be used.
The 2013 edition of the standards also covers levels of protection “da” (only applies to catalytic sensors for portable gas detectors), and “dc” (devices or components with switching contacts – dc applies to “enclosed break” devices formerly covered under the Ex n standard 60079-15)
Level of protection “da” has EPL “Ma” or “Ga” ; “dc” has EPL “Gc”.
Other than the specific requirements for level of protection “da” and “dc”, all requirements of the standard apply to level of protection “db”.
Flameproof equipment is designed for uses with particular Group II gas subdivisions (IIA,IIB and or IIC), and may only be used in the appropriate gas hazards
Ambient Conditions:
Unless otherwise marked, flameproof enclosures are designed for use in ambient temperatures in the range -20° to +40°C.
