IP55 motors for outdoor use: protection, applications, and key considerations
When electric motors are used outdoors, they are exposed to moisture, dust, rain, and temperature fluctuations. It is therefore essential to know whether a motor is designed to withstand these conditions. IP55 motors provide a solid level of protection against such environmental factors. But what does IP55 actually mean, where should you (or shouldn’t you) use these motors, and what are the main points to consider during outdoor installation? In this article, we explain everything and share expert advice based on the latest insights.
What does IP55 mean?
The IP code (Ingress Protection) indicates the degree of protection an electric motor offers against dust and water ingress. The IP55 rating means the motor is:
- Partially dust-tight: Some dust may enter, but not in quantities that affect the motor’s operation.
- Protected against water jets from any direction, at limited pressure and volume.
For many outdoor applications, this is sufficient. Note: IP55 is not waterproof. The motor must not be exposed to standing water or full immersion for extended periods.
| First digit (protection against objects/dust) | Description |
|---|---|
| 0 | No protection |
| 1 | Protection against objects larger than 50 mm |
| 2 | Protection against objects larger than 12 mm |
| 3 | Protection against objects larger than 2.5 mm |
| 4 | Protection against solid objects larger than 1 mm |
| 5 | Dust-protected |
| 6 | Completely dust-tight |
| 2nd digit (protection against water/moisture) | Description |
|---|---|
| 0 | No protection |
| 1 | Protection against vertically falling drops and condensation |
| 2 | Protection against drops falling at up to 18° from vertical |
| 3 | Protection against drops falling at up to 60° from vertical |
| 4 | Protection against water splashes (from all directions) |
| 5 | Protection against water jets (from all directions) |
| 6 | Protection against powerful water jets (sea waves) |
| 7 | Protection against short-term immersion at limited depth |
| 8 | Protection against long-term immersion at great depth (pressure-proof) |
Typical applications of IP55 motors
IP55 motors are commonly used in industrial settings where the motor is partially or fully installed outdoors. Examples include roof-mounted fans, pumps in the agricultural sector, or drive systems on outdoor production lines. They are also widely used in horticulture and air-handling units. In these contexts, the IP55 classification offers an excellent balance between protection and cost-efficiency.
Key considerations for outdoor installation
An IP55-rated motor does not guarantee flawless performance in every outdoor scenario. Its reliability depends greatly on proper installation:
- Mounting position is crucial. In vertical setups, water may enter through the top cover. A rain hood or drip shield is recommended.
- Ensure correct sealing of cable glands and that the gaskets in the terminal box are intact. Worn or incorrectly fitted glands can compromise protection.
- Consider installing drain plugs or breather valves to equalize pressure and prevent internal condensation.
A well-installed motor significantly reduces the risk of malfunctions and extends service life.
Below is a table with key installation points for outdoor IP55 motors, highlighting common mistakes and best practices.
| Component | Correct installation | Incorrect installation |
|---|---|---|
| Mounting position | Horizontal or with rain cover when mounted vertically | Vertical without protection: water can enter from the top |
| Terminal box / cable glands | Properly tightened glands with intact sealing | Glands not tightened or without sealing: risk of moisture ingress |
| Water drainage | Condensation holes or breather plugs installed at the bottom of the motor | No provision for condensate drainage: risk of internal corrosion |
| Rain protection | Rain cover or canopy present | Fully exposed to heavy rain or standing water |
| Cabling | Cable entry from below or through a sealed gland | Cable enters from above, allowing water to run along the cable |
| Regular maintenance | Visual inspection and periodic check of seals | No inspection: seal wear detected too late |
When is IP55 not sufficient?
In demanding environments—such as heavy industry, marine applications, or very dusty factories—a higher IP rating may be required, for example:
- IP65 for complete dust-tightness and protection against powerful water jets.
- IP66 where protection from heavy rainfall or pressure cleaning is critical.
- IP67 if the motor may be temporarily submerged, e.g., in flood-prone areas.
Additionally, there are special versions, such as explosion-proof (ATEX) motors for hazardous zones or motors with extra coatings for chemically aggressive environments.
Want to ensure your application meets the latest energy standards? Also read our article on the ErP Directive for fans and electric motors.
Summary
The motors we typically use have an IP55 protection rating. IP55 motors are suitable for many outdoor applications, provided they are installed correctly and match the environmental conditions.
For more demanding situations, motors with a higher IP rating or additional protective features are a better choice.
If needed, you can opt for a higher IP class or install a rain cover over the motor to prevent water ingress.
Not sure which motor is right for your application? Contact us – we’re happy to help.
Need advice? Get in touch!
We’re available Monday to Friday from 8:30 to 17:00.
Frequently Asked Questions about IP55 for outdoor use
Are IP55 motors completely waterproof?
No, IP55 motors are protected against water jets but not against immersion or prolonged water exposure. For full waterproofing, consider higher ratings such as IP67.
Can IP55 motors be used in all outdoor environments?
IP55 motors suit many outdoor settings, but in areas with extreme weather or high dust levels, a higher IP rating may be required.
How do I maintain an IP55 motor outdoors?
Regularly check for damage, ensure seals are intact, and avoid water pooling. For vertical installations, a rain hood is strongly recommended.