CompEx `n` – Reduced Risk
Electrical equipment within CompEx type of protection `n` is such that in normal operation and in certain specified fault conditions it is not capable of igniting a surrounding explosive atmosphere.
Areas of usage:
- Zone 2 or Category 2 or EPL GC
- All gas groups
Ingress protection
CompEx type of protection `n` requires IP54 as a minimum.
Protection details
CompEx `n` standard is subdivided into several other types of which the following are most commonly used:
- Ex `n` C
- Ex `n` R
- Ex `n` L
Ex `n` C
Ex `n` C standard is further subdivided in to these categories:
- Hermetically sealed devices - Sparking contacts are enclosed within a hermetically sealed enclosure.
- Enclosed break devices – Break devices are incorporated within an enclosure that is capable of withholding an internal explosion (recently replaced by Ex `d` standard).
- Encapsulated devices – Similar to hermetically sealed devices (recently replaced by Ex `m`).
Ex `n` R`
Ex `n` R standard stands for Restricted Breathing devices. This type of protection is designed to restrict, but not totally prevent the entry of gases.
Ex `n` R protection is very common with various types of luminaries used in the oil and gas industry.
Cable entries into restricted breathing enclosures must be fitted with an IP washer.
Ex `n` L
Ex `n` L stands for Energy Limited Apparatus. This is a type of protection where circuit components restrict the maximum available energy in a circuit to a level incapable of causing an explosion.
Accessories
| Accessories | Required type |
|---|---|
| Glands | Certified glands only:
|
| Blanks | Certified blanks only:
|
| IP washer |
|
| Serrated washer | Required on painted surfaces |
| Locknut |
|
| Earth tag | Required on plastic enclosures without earth continuity plates |
