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Liquid and/or solid particle ingress into electrical equipment can not only be harmful to the equipment, it can be dangerous to the operator. Therefore when buying electrical equipment whether it be an electric motor, a light fiiting or an instrument, it is essential to know what degree of "ingress protection" the item offers.
The applicable European standards for ingress protection are:
- BS EN 60529 Specification of Degrees of Protection Provided by Enclosures
- IEC 529 Specification of Degrees of Protection Provided by Enclosures
Both of these provide a numerical code to help classify the degree of protection offered, as shown below:
| Ingress Protection Classification | |||
| First Number | Second Number | ||
| IP | Protection Provided | IP | Protection Provided |
| 0 | No Protection | 0 | No Protection |
| 1 | Protected against solid objects up to 50mm e.g. accidental touch by hands | 1 | Protected against vertically falling drops of water e.g. condensation |
| 2 | Protected against solid objects up to 12mm e.g. fingers | 2 | Protected against direct sprays of water up to 15 deg from the vertical |
| 3 | Protected against solid objects over 2.5mm e.g. tools | 3 | Protected against direct sprays of water up to 60 deg from the vertical |
| 4 | Protected against solid objects over 1mm e.g. wires | 4 | Protected against water sprayed from all directions - limited ingress permitted |
| 5 | Protected against dust - limited ingress (no harmful deposit) | 5 | Protected against low pressure jets of water from all directions - limited ingress permitted |
| 6 | Totally protected against dust | 6 | Protected against strong jets of water e.g. for use on shipdecks - limited ingress permitted |
| 7 | Protected against the affects of immersion between 15cm and 1m | ||
| 8 | Protected against long periods of immersion under pressure | ||
European and North American Comparison
In North America, the NEMA classification is used in preference to the IEC codes shown above.
The IEC and NEMA degrees of protection can not be fully compared as equivalent ratings - see below. The NEMA Standard includes tests for environmental conditions such as mechanical damage, corrosion, rusting, ice formation, etc.
Further information can be found about the North American classification scheme in NEMA Standard Publication 250 and UL 40 Standard Publication.
| NEMA Enclosure Type Number |
Approximate IEC Classification |
| 1 | IP 10 |
| 2 | IP 11 |
| 3 | IP 54 |
| 3R | IP 14 |
| 3S | IP 54 |
| 4 and 4X | IP 56 |
| 5 | IP 52 |
| 6 and 6P | IP 67 |
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