IP protection rating of the power supply
The protection level indicates the degree to which electrical equipment is protected against the ingress of foreign objects and moisture. In this article, you will learn what IP protection levels exist, how they differ from each other, and what to pay attention to when selecting a power supply.
Environmental influences such as dust or moisture can affect the functionality of electrical components in power supplies. Additionally, it may be necessary to protect the interior of the equipment from the ingress of foreign objects such as tools, screws, or wires, or to prevent user contact. Particularly when using power supplies outside of electrical cabinets, the protection level, known as the IP code (International Protection code), should be considered during selection. Only when the protection level matches the environmental conditions can the power supply be safely used, avoiding costly failures.
What are IP protection levels?
The protection level is typically denoted by the abbreviation IP ("International Protection"; often referred to as "Ingress Protection" in English) followed by two digits (e.g., IP20, IP54, IP67, etc.).
The first digit indicates the level of protection against contact and the ingress of foreign objects, sand, and dust. The second digit indicates the level of protection against water and moisture.
For industrial power supplies, the protection level is determined in accordance with the DIN EN 60529 standard. For road vehicles, the ISO 20653:2013 standard is also commonly applicable. However, this standard only applies to vehicle electrical components that require additional protection against high-pressure cleaning (e.g., using steam jets).
In the context of power supplies, the protection level is sometimes confused with the classification for protection against electric shock. The protection level refers to protection against foreign objects, water ingress, and contact, whereas the IEC classification for protection against electric shock specifies the construction and insulation of power supplies to protect users from electric shocks.
The table below provides an overview of the meanings of the digits in IP protection levels:
Protection Against Foreign Objects (First Digit)
| Digit | Definition |
|---|---|
| 0 | No protection |
| 1 | Protected against solid objects with a diameter ≥ 50 mm (e.g., hands) |
| 2 | Protected against solid objects with a diameter ≥ 12 mm (e.g., fingers) |
| 3 | Protected against solid objects with a diameter ≥ 2.5 mm (e.g., tools) |
| 4 | Protected against solid objects with a diameter ≥ 1 mm (e.g., wires) |
| 5 | Fully protected against contact and dust |
| 6 | Fully protected against contact and completely dust-tight |
Protection Against Water (Second Digit)
| Digit | Definition |
|---|---|
| 0 | No protection |
| 1 | Protected against vertically falling drops of water |
| 2 | Protected against vertically falling drops of water when the enclosure is tilted up to 15° |
| 3 | Protected against water spray at angles up to 60° from vertical |
| 4 | Protected against splashing water from any direction |
| 5 | Protected against water jets from any direction |
| 6 | Protected against powerful water jets from any direction |
| 7 | Protected against temporary immersion |
| 8 | Protected against continuous immersion |
| 9 | Protected against high-pressure and high-temperature water jets |
What are the common protection ratings for industrial power supplies?
The required protection rating depends on the installation location and the environmental conditions in the corresponding application. Manufacturers that supply power supplies from stock typically only offer products with selected IP protection ratings, which have become industry standards. The table below outlines the most common protection ratings for industrial power supplies.
| Protection Rating | Foreign Objects (Digit) | Protection Against Foreign Objects | Water (Digit) | Protection Against Water |
|---|---|---|---|---|
| IP20 | 2 | Protected against solid objects with a diameter ≥ 12 mm (e.g., fingers) | 0 | No protection |
| IP54 | 5 | Fully protected against contact and dust | 4 | Protected against splashing water from any direction |
| IP65 | 6 | Fully protected against contact and completely dust-tight | 5 | Protected against water jets from any direction |
| IP67 | 6 | Fully protected against contact and completely dust-tight | 7 | Protected against temporary immersion |
