What are the protection classes of the electrical equipment of automation technology?
The protection classes are also called IP codes. IP stands for Ingress Protection.
Table 1 shows the structure of the IP code.
|2||First numeral||The first numeral indicates the protection against ingress of foreign objects (including dust) and the degree of the shock-hazard protection for people.|
|0||Second numeral||The second numeral indicates the protection against damaging effects caused by the ingress of water.|
Table 2 shows the different definitions of the first numeral.
|Protection of equipment||Protection of people|
|0||No protection||No protection|
|1||Protection against large, solid foreign objects up to 50 mm in diameter||Protection against access with the back of the hand|
|2||Protection against medium-sized, solid foreign objects larger than 12.5 mm in diameter||Protection against access with a finger|
|3||Protection against small, solid foreign objects larger than 2.5 mm in diameter||Protection against access with tools and wires larger than 2.5 mm in diameter|
|4||Protection against granular, solid foreign objects larger than 1.0 mm in diameter||Protection against access with tools and wires larger than 1.0 mm in diameter|
|5||Protection against dust deposits||Complete protection against body contact|
|6||Protection against dust entry||Complete protection against body contact|
Table 3 shows the definitions of the second numeral.
|Protection against water|
|1||Protection against vertically dripping water|
|2||Protection against dripping water (15° angle)|
|3||Protection against spraying water|
|4||Protection against splashing water|
|5||Protection against water jets|
|6||Protection against flooding|
|7||Protection during temporary immersion|
|8||Protection during continuous immersion|
The protection classes below apply to the electrical equipment of automation technology.
- IP20 for control cabinet components
- IP65, IP66, IP67, IP68 and IP69K for field components
- IP65: Protected from total dust ingress. Protected from low pressure water jets from any direction, limited ingress protection
- IP67: Dust tight and protected against immersion up to 1 m depth
The protection types IP67 and IP68 do not include the protection types IP65 and IP66.
The following external influences to which the electrical equipment used might be exposed to during operation are to be taken into account when planning and installing electrical systems:
- Chemical influences like oils and detergents, for example
- Extreme temperatures and formation of ice
- Solar radiation (UV radiation)
- Salt fog
More observations and possibly more protective measures are required for this.
Additional protective measures of products in the higher protection types IP6x
Products may have properties that permit use under other influences.
- Temperatures down to -40°C and formation of ice
- Explosion protection in compliance with ATEX Zone 2/22
- Temperature shock testing in compliance with IEC 60068-2-14 Na
- Condensation water / alternating climate according to DIN EN ISO 6270-2
- Salt spray according to IEC 60068-2-52
- Pollutant concentrations
SO2: <0.5 ppm
H2S: <0.1 ppm
- Vibrations up to 40 g according to IEC 60068-2-6
Additional protective measures of products in lower protection type IP20
Standard products can be strengthened through additional measures. SIEMENS provides the SIPLUS extreme product line based on standard products. The SIPLUS extreme product line offers:
- High reliability in extended temperature ranges of -40°C/-25°C up to +60°C/+70°C for cold start and continuous operation.
- Protection against bedewing and formation of ice. The SIPLUS extreme product line is permitted for 100% bedewing, condensation and formation of ice.
- Protection against salty atmosphere. A salt fog test in compliance with IEC 60068-2-52 is conducted for the SIPLUS extreme product line.
- Protection against harmful gases and chemically active substances. A test in compliance with EN 60721-3-3 3C4 is conducted for the SIPLUS extreme product line.
Note on the protection against oils and detergents
Automation components on the field level often come into direct contact with oils and detergents.
The IP protection type according to DIN EN 60529 is not effective for this equipment, because:
- The creep properties of water might vary and it might therefore not be able to guarantee water tightness.
- The chemical properties might have a long-term effect on the product equipment (housing, cables, etc.).
In such cases it always necessary to see exactly which oils and detergents are used on which automation components.