CompEx `n` Reduced Risk | SparkyFacts.co.uk

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:
  • Ex `d`
  • Ex `d` barrier
  • Ex `de`
  • Ex `e`
Blanks Certified blanks only:
  • Ex `d`
  • Ex `de`
  • Ex `e`
IP washer
  • Clearance entry - required
  • Threaded entry less than 6mm thread – required
  • Threaded entry more than 6mm thread – not required
  • Ex `n` R - required
Serrated washer Required on painted surfaces
Locknut
  • Clearance entry – required
  • Threaded entry less than 6mm thread – required
  • Threaded entry more than 6mm thread – not required
  • Plastic enclosures - required
Earth tag Required on plastic enclosures without earth continuity plates



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