Relation of Ex d rating, Ex e rating with IP ratings

[NickParker]

I would like to know the relation between Ingress Protection (IP) & Explosion protection (Hazardous area classification). If there is a Ex certified equipment, is there any minimum requirement on its IP rating (though IP rating depends on exposure to ingress of water/liquid & solid items)?

For example, what is the minimum IP rating required for Ex e certified equipment? what is the minimum IP rating required for Ex d certified equipment?

I could not see the IP ratings in most of the Ex certificates which are "Ex d" or "Ex e", but can see they are also certified for dust protection

 

[che12345]

Dear Mr. NickParker (Electrical)(OP)11 Mar 22 09:47
"..#1.I would like to know the relation between Ingress Protection (IP) & Explosion protection (Hazardous area classification). #1.1 If there is a Ex certified equipment, is there any minimum requirement on its IP rating (though IP rating depends on exposure to ingress of water/liquid & solid items)?
#2. For example, what is the minimum IP rating required for Ex e certified equipment? what is the minimum IP rating required for Ex d certified equipment?
#3. I could not see the IP ratings in most of the Ex certificates which are "Ex d" or "Ex e", but can see they are also certified for dust protection."
I try to answer your learned/valid questions
#1 There is NO relationship between IP and Ex standards. They cover different scopes/areas of application.
#1.1. NO, see above #1.
#2. Ex or Ex d certification does NOT carryout IP testing. See above #1.
#3. The "dust" in IP testing is NOT an " explosive dust " considered in the Ex ... certification.
Che Kuan Yau (Singapore)

 

[JezNZ]

I disagree (in part) with the post above.

If you read IEC 60079-7 you will indeed find there are specifications for IP ratings. For example in section 4.10.1 "Degrees of protection provided by enclosures".

 

[SwinnyGG]

The two concepts (ingress protection and explosion protection) seem to be related, but really they aren't.

The point of IP is to make whatever is inside an enclosure survive should the enclosure be exposed to a certain set of environmental conditions.

The point of Ex is to make whatever and whoever is OUTSIDE an enclosure not die in a giant ball of flame should whatever is INSIDE the enclosure experience any manner of electrical fault. Different horses for different courses.

 

[Gr8blu]

Nick An enclosure rated as "Ex d" (flameproof) is designed to contain an explosion and stop any flames, sparks, and hot gases from escaping into the surrounding atmosphere should an internal explosion occur. In addition, an Ex d enclosure protects the fitted equipment against external moisture, dirt, dust, or water. The enclosure may house equipment such as, contactors, relays, power supplies, transformers, radio devices and other electrical equipment with potentially hot surfaces. Sometimes referred to as ‘flameproof’ or “explosion-proof”, an Ex d enclosure includes what is known as a flame path. The flame path design can vary depending on the construction of the Ex d enclosure system.

An enclosure rated "Ex e" (increased safety) is an explosion protection concept applied to the installation to ensure increased security against the possibility of excessive temperatures and sparks from hazardous area electrical equipment. Equipment that normally causes sparks is excluded from use within this method of explosion protection. ‘Ex e’ means that an enclosure is constructed and certified as Explosion Protected according to the Increased Safety standard. The intention of the Ex e Increased Safety standard is to provide an impact resistant enclosure for electrical equipment and also to ensure that the contents will not produce a spark, temperature or current creepage that could ignite the external flammable atmosphere in a hazardous area zone, location or workspace.

Given the two descriptions above, the minimum acceptable IP comparison for either would be IP 54. More likely it would be IP 65 or better, because of the requirement for the flame path. You MIGHT find a rotating machine with an IP 44 rating that meets the intent of Ex e by eliminating all sparking contacts and/or "hot" spots.

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