Standardised protection against contact, foreign matter and water
The protection of an enclosure against penetration by foreign matter and water is identified by a letter-number combination. The resulting code defines standardised levels of protection, which are stated as a protection rating.
The protection that an enclosure can provide by encasing hazardous or sensitive parts is identified in accordance with IEC 60529 by means of a combination of numbers and letters.
and is specified as a protection rating by means of the IP code (International Protection).
If the protection rating is specified by means of the code numbers (e.g. IP 54), the first digit applies to both the foreign matter protection and also protection against contact. If the protection rating is specified by means of the “additional letters” (e.g. IP 20C), the first code number applies only to the foreign matter protection, and the “additional letter” describes the contact protection.
A distinction is made between protection against direct contact and protection against penetration by foreign matter. In principle, both are specified simultaneously in the first numerical code.
In the second edition of IEC 60529 published in 2000, the difference between protection against direct contact (basic protection) and protection against penetration by solid matter was addressed for the first time; in principle both of these defined simultaneously by the first code number.
In some cases, however, the protection against direct contact is more important, and the level of protection to be chosen is higher than the protection against penetration by solid foreign matter. This often results in misunderstandings in the specification. in accordance with IEC 61439, general protection against direct contact in switchgear assemblies, for example, does not have to be IP 20 but only IP XXB. If IP 20 is required for other reasons, then IP XXB is automatically covered as well.
The distinction is critical in the realisation of higher protection ratings (e.g. IP 4X), which is best clarified using the description of the test methodology:
This fact means that some enclosures that were originally designed as IP 4X only comply with IP 3XD or less by today’s evaluation benchmarks. In most cases, this is also sufficient for an outdoor installation. However, for some applications (e.g. in the construction site environment) a “real” IP 4X is required.
All of our enclosure series were tested in accordance with current criteria (60529 ÖVE / ÖNORM EN: 2014) and certified by the Austrian Electrotechnical Association (ÖVE). Our polyester enclosures (cabinets and pillars) comply with protection rating IP 44 when assembled. On request, they can also be designed to be protected against dust (IP 54).
In some cases it may be necessary also to implement a protection rating that is lower than IP 44 due to certain operating conditions such as, for example, increased dissipated heat inside the enclosure. This could be done, for example, by the subsequent installation of ventilation grilles of a lower protection rating. Our TECHNICAL SALES department would be happy to advise you on these topics.
In some switchgear assemblies, a defined minimum protection rating must also be maintained even after opening the enclosure. For distributors complying with IEC 61439-3, this is IP 2XC when there is provision for operation by electrical laypersons (installation distributors, metering distributors). To be generally considered as basic protection in accordance with IEC 60364, an enclosure or contact protection cover must comply with at least IP XXB.
However, the specification “XX” is not suitable to represent the actual protection rating of the product. The protection rating is measurable; hence the “X” is an inadequate specification. If no protection against penetration by water is required or realised when the case is opened, then the correct specification is IP 20C. Likewise, the “X” is not regarded as a product specification for protection ratings of the outsides of enclosures. Here, the specification can be IP 44 or IP 54, for example, but cannot be IP 4X or IP X4.