There are two main organisations that provide standards for enclosures. These are the National Electrical Manufacturers Association (NEMA) and the International Electrotechnical Commission (IEC). NEMA mainly govern North America, the IEC however is more accepted worldwide and will be discussed here.
IP ratings come under the IEC60529 regulations. IEC60529 governs standards of protection that enclosures provide when they are properly installed.
The IP rating itself is split into three parts:
1. The ‘IP’ part of the rating stands for Ingress Protection and is standard among the ratings.
2. The first digit of the rating is defines protection against solid objects
3. The second digit of the rating defines protection against liquid
The tables below show a summary of some of the values of each of these digits:
Table 1 - First Digit
| Digit | Description |
| 0 | No Protection |
| 1 | Protected from objects over 50mm |
| 2 | Protected from objects over 12mm |
| 3 | Protected from objects over 2.5mm |
| 4 | Protected from objects over 1mm |
| 5 | Protected against Dust - not dust proof but dust cannot enter in sufficient quantity to effect operation |
| 6 | Dust Tight |
Table 2 - Second Digit
| Digit | Description |
| 0 | Not Protected |
| 1 | Protected against dripping water dripped from vertically above |
| 2 | Protected against dripping water dripped when enclosure is tilted to an angle of 15 degrees |
| 3 | Protected against spraying water. Water falling at an angle of 60 degrees as a spray |
| 4 | Protected from splashing water. Water from any direction will have no adverse effect |
| 5 | Protected against jets of water |
| 6 | Protected against powerful jets of water |
| 7 | Protected against brief emmersion in water |
| 8 | Protected against submersion in water |
For more information about this standard please visit the IEC website at www.iec.ch.
References:
http://www.nexus.com.tr/file_upload/downloads/note_ipclass.htm
http://www.ab.com/catalogs/safety/prodtypepdf/ch0/0-9_0-10.pdf
http://www.lumascape.com/html/IP_IK_rating.htm
**Please note this is only a brief introduction to IP ratings and as such does not reflect the exact IEC60529 standard. SmartPowerShop will not be held responsible from any damage caused as a result of reading this article.
Last Updated: May 13, 2008
