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Equipment Marking




X-Condition on Certificate

Remember to always check to see if the Certificate number marked on the equipment label ends with the letter X. If it does, then there are some special (unusual or restrictive) conditions of installation or use. You must check the certificate or ATEX documentation pack which was supplied with the equipment to understand the special conditions and ensure your installation / use will fully comply. Failure to understand and comply with X-conditions means that the equipment is being used outside its certification conditions and may not be safe.


General Form of Hazardous Area Electrical Equipment Marking

The type of protection may any be any one, or a combination two or more of the types of protection shown in the tables on the Hazardous Area Basics page of this site.


If the code contains just the letters "II" (without a sub group letter: A, B or C) then the equipment is suitable for all surface industry sub groups: IIA, IIB and IIC


If the EEx ia or Ex ia appears in brackets: [EEx ia] or [Ex ia] then the equipment is Associated Apparatus and is intended to be located in the non-hazardous area. (This will be found on equipment such as zener barriers and galvanic isolators which are the safety interface units for an intrinsically safe circuit which is connected to the output terminals of the Associated Apparatus.


General Form of ATEX Marking

For information showing how the relationship between Equipment Category and permissible zone(s) of use, Click Here

For information of the Equipment Category for the different types of protection, Click Here

The ATEX marking will be additional to the general hazardous area equipment marking and the two sets of data may be combined into one string


It is not uncommon for equipment to be designed to be suitable for both Gas/Vapour and Dust hazards, so the Equipment Category may show both Gas/Vapour and Dust categories, for example: II 2G 2D would mean the equipment was suitable for Gas/vapour zones 1 and 2 and dust zones 21 and 22


Marking of Equipment for Dust Hazard Locations


Equipment marking can get horribly complex. Equipment certified to both IEC and European requirements adds to the complexity as does equipment intended for both gas/vapour and dust hazards. The best guidance I can give you is to look at the label information and see if you can find the bits of information which are relevant to your situation / use. Don't let all the other stuff befuddle you!

Also, be aware that the types of protection and the way in which the codes are applied are always changing. (Like, for example, the fact that the first E of EEx has now been dropped and we are back to Ex, which is where we were years ago!) So don't be put off if the code form does not exactly follow the above examples.


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