Bob asks this question, which concerns an electrical enclosure, what IPxxB means in relation to it, and its compliance with the regulations. It has been answered by SELECT (Theme – Regulations and Legislation):
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Question: Firstly, what does IPxxB mean, and secondly where is an 'appropriate' place for an electrical enclosure (lowbay) to be installed when it is only IP1x when suspended (i.e. has large holes <40mm on the back of it)?
This is relating to 713-07-01 of BS 7671: 2008.
Also, can this fitting be installed as expected (trunk mounted 4 - 5m high) with the large holes open, and still comply?
Answer: IP Codes for ingress protection are given in BS EN 60529:1991, which is a standard used to form the basic requirements of electrical equipment standards.?
The degree of protection provided by an enclosure is indicated generally by two numbers and followed by an optional letter and / or optional supplementary letter, e.g. IP 44 B H.
The first numeral indicates the level of protection against ingress of solid foreign bodies and protection against access to hazardous parts inside an enclosure.
The second numeral refers to the level of protection against ingress of water. If not required, the numeral can be replace by X or XX.
The additional letter indicates the degree of protection of persons against access to hazardous parts. It is only used if the protection against access to hazardous parts is higher than that indicated by the first character, or if only the protection against access to hazardous parts, and not general ingress is indicated, the first character numeral being replaced by X.
The letter B - is protection against access with a finger (minimum 12mm diameter test finger, 80mm long) - adequate clearance from live parts.
IP1X - is generally protection against access to hazardous parts with the back of the hand and protection against foreign solid objects of 50mm diameter and greater.
Regulation 713-07-01 requires that the verifier ensures that the specified level of protection against direct contact is achieved - use the above as guidance, i.e. if the designer has specified xxB - you should not be able to stick a finger into the equipment and touch live parts, and if IP1X is specified, then as long as openings are less than 50mm, this is satisfied.
If the fitting cannot be installed with this level of protection - the designer should be consulted to either review the equipment specified or to assess the risks if using the type specified and to ensure safety.
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