Type

Description of Protection Method

Ex d

Flameproof Enclosures
Flammable gases & vapors are expected inside an enclosure, the equipment must be capable of withstanding an explosion caused by sparking contacts, high temperatures, or an electrical fault.

Ex e

Increased Safety
Type of protection applied in electrical components do not produce arcs or sparks in normal service and under specified abnormal conditions.

Ex i

Intrinsic Safety
Apparatus used in a potentially explosive area contain intrinsically safe electric circuits only. An electric circuit is intrinsically safe if no sparks or thermal effects are produced under specified test conditions (which include normal operation and specific fault conditions) which might result in the ignition of a specified potentially explosive atmosphere.

Ex p

Purged and Pressurized
This type of protection prevents the surrounding atmosphere from entering an enclosure by maintaining a positive pressure within the unit. Clean air or inert gas is used to maintain a higher pressure than the surrounding atmosphere.

Ex m

Encapsulation
Encapsulation is a type of protection in which the parts that can ignite an explosive atmosphere are enclosed in resin. The resin must be sufficiently resistant to environmental influences so that the explosive atmosphere can not be ignited by either sparking or heating, which may occur within the device.