Definition #
Type ‘n’ protection is a type of protection applied to electrical equipment such that in normal operations and in certain specified regular expected occurrences, it is not capable of igniting a surrounding flammable gas atmosphere.
Type ‘N’, a UK innovation, become an accepted method of explosion protection in Europe as type ‘n’ to EN50021. Type ‘n’ is now accepted internationally to IEC60079-15.
Equipment Protection Level (EPL): Gc #
Type ‘n’ equipment is basically similar to increased safety type ‘e’ equipment, but that there is a relaxation in the constructional requirements because it can only be used where the required EPL is Gc. Generally, this means locations in Zone 2 only, unless a risk assessment indicates differently.
Standards #
| Current constructional standards | |
| IEC 60079-15: 2010 BS EN 60079-15: 2010 | Explosive atmospheres – Parts 15: Equipment protection by type of protection ‘n’ |
| Original standard | |
| BS 6941: 1988 | Electrical equipment for explosive atmospheres with type of protection N |
| Codes of Practice | |
| IEC 60079-14: 2013 BS EN60079-14: 2014 | Electrical Equipment for explosive gas atmospheres: Part 14 Electrical installations in hazardous areas (other than mines) |
| IEC 60079-17: 2013 BS EN60079-17: 2014 | Electrical Equipment for explosive gas atmospheres: Part 17 Inspection and Maintenance of electrical installations in hazardous areas (other than mines) |
Ambient Conditions: #
Unless otherwise marked, type ‘n’ enclosures are designed for use in ambient temperatures in the range -20°C to +40°C.
IP Rating #
The minimum IP rating for Ex n equipment containing bare live parts is IP54. For enclosures with no bare live parts IP44 is sufficient.
