IP stands for Ingress Protection, a rating system that defines how well an electrical enclosure prevents solids and liquids from entering.
The first digit indicates the level of protection against solids, including dust
The second digit indicates the level of protection against water exposure
Higher numbers represent higher levels of protection
IP ratings are used to match an enclosure to its environment, based on the type of conditions it is expected to withstand in the field.
How IP Ratings Are Structured
IP ratings use the following two-digit format:
First Digit: Protection Against Solids
Rating | Protection Level |
0 | No protection |
1-4 | Protection against larger solid objects |
5 | Dust-protected with limited ingress allowed |
6 | Dust-tight with no ingress |
Second Digit: Protection Against Liquids
Rating | Protection Level |
0 | No protection |
1-4 | Protection against dripping or splashing water |
5-6 | Protection against water jets |
7 | Protection during temporary immersion |
8 | Protection during prolonged or defined immersion |
What IP Ratings Do and Do Not Define
IP ratings define how well an enclosure resists dust and water under specific test conditions.
An IP rating addresses dust and water ingress, not material durability or environmental resistance.
They do:
Provide a standardized way to compare protection levels
Indicate suitability for different environments
Help guide enclosure selection
They do not:
Define material durability
Address corrosion resistance
Specify installation conditions
Guarantee performance outside test parameters
IP ratings describe ingress protection only, not overall enclosure performance.
How IP Ratings Apply to Electrical Enclosures
IP ratings are used to match an enclosure to the type of exposure it will encounter.
For example:
Lower ratings apply to indoor or controlled conditions
Mid-range ratings apply to outdoor or washdown environments
Higher ratings apply to immersion or flood-prone conditions
The correct rating depends on how dust and water are expected to interact with the enclosure.
Understanding Common IP Ratings
Some IP ratings are used more frequently than others in electrical applications.
IP65 and IP66
Protection against dust and water jets
Common in outdoor and industrial environments
IP67
Protection during temporary immersion
Used where brief submersion is possible
IP68
Protection during prolonged or defined immersion
Used in flood-prone, underground, or submerged applications
Each rating corresponds to a different type of exposure, not just a higher level of protection.
IP Ratings vs NEMA Ratings
IP and NEMA ratings both define enclosure protection, but they are not the same.
IP ratings focus specifically on dust and water ingress. NEMA ratings include additional factors such as corrosion, oil, and environmental durability. While the two systems can be compared, they are not directly interchangeable.
Choosing the Right IP Rating for Your Application
Selecting the correct IP rating begins with understanding the environment.
Key Questions:
Will dust be present?
Will water be splashing, sprayed, or surrounding the enclosure?
Is immersion possible?
What type of exposure is expected during normal operation?
The goal is to match the rating to the actual conditions the enclosure will face.
Why IP Ratings Matter in Electrical Enclosures
Choosing the correct IP rating helps ensure:
Reliable operation
Protection of internal components
Reduced risk of failure due to environmental exposure
Selecting the wrong rating can result in:
Premature equipment failure
Increased maintenance
Unexpected downtime
