Various defined protection methods can be utilised to mitigate the risks associated with the hazards of a hazardous area. These protection methods are engineered solutions to either remove one of the parameters required for an explosion or in the case of Ex d flameproof contain any explosion to prevent it propagating outside the protection containment.
All electrical equipment in the hazardous area must comply with EN 60079-0 the general standard, except were it is overridden by one of the other standards specific to the protection method.
The primary electrical protection methods are:
Code | Protection Concept |
Standard | Notes & Principles |
---|---|---|---|
Ex d | Flameproof | EN 60079-1 | Contain the Explosion |
Ex e | Increased Safety | EN 60079-7 | High Integrity Non Sparking |
Ex i | Intrinsic Safety | EN 60079-11 | Power limitation |
Ex t | Enclosure | EN 60079-31 | Keep out the dust (Not for Gas) |
Ex n | Various1 | EN 60079-6 | non sparking |
Ex p | Pressurised | EN 60079-2 | see EN 61241-4 for Dust |
Ex m | encapsulated2 | EN 60079-18 | rarely used on its own |
Ex o | Oil Filled | EN 60079-6 | Rarely used |
Ex q | Powder filled | EN 60079-05 | Rarely used |
Ex s | special | EN 60079-33 | Used when no other method applies |
Note
The EN60079-6 standard for Ex n (for use in Category 3G only) covers a number of protection techniques, Ex nA Non-Sparking, Ex nC Enclosed Break and Ex nR Restricted Breathing. ↩
if an item is entirely encapsulated it has not connections i.e. aportable device. Ex m is either used as a component with trailing cables or more commonly in confunction with another protection method such as Ex em. ↩