Motors for Zone 2 in Process Plants

BS EN 60079 gives details.

In general terms:

• 'Increased safety' (or EEx 'e') refers to a method of construction and use of terminal boxes that makes in unlikely for an incendive spark to occur inside it.
• 'Flameproofing' (or EEx 'd') means constructing the equipment in such a way that any internal explosion is contained within the enclosure without rupture and any flame path arranged so that an internal explosion cannot ignite a surrounding flammable atmosphere.

It is quite in order for a motor to be certified EEx 'de', which usually means a flameproof motor with an increased safety terminal box.