What Does IP Mean in Electrical Enclosures?

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

Second Digit: Protection Against Liquids

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.

For a deeper look at how IP68 is defined and used in the field, see IP68 Electrical Enclosures and Junction Boxes: What They Are and When to Use Them.

IP Ratings vs NEMA Ratings

IP and NEMA ratings both define enclosure protection, but they come from different systems and are not directly interchangeable.

For a full comparison of what each system covers and how to choose between them, see How to Choose the Right NEMA or IP Rated Enclosure for Your Application.

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

Frequently Asked Questions (FAQs)

What do the two digits in an IP rating actually mean?

The first digit indicates protection against solids, including dust, while the second digit indicates protection against water exposure. Higher numbers within each digit represent higher levels of protection.

Does a higher IP rating always mean better protection for my application?

Not necessarily. Each rating corresponds to a different type of exposure, not just a higher level of protection. An enclosure rated for temporary immersion (IP67) is built for a different scenario than one rated for water jets (IP66), so the right rating depends on matching the number to the actual exposure conditions rather than picking the highest one available.

What does an IP rating NOT tell you about an enclosure?

IP ratings describe ingress protection only. They don't define material durability, address corrosion resistance, specify installation conditions, or guarantee performance outside the specific test parameters used to earn the rating.

What's the difference between IP65, IP66, IP67, and IP68?

IP65 and IP66 protect against dust and water jets and are common in outdoor and industrial environments. IP67 protects during temporary immersion, while IP68 protects during prolonged or defined immersion, used in flood-prone, underground, or submerged applications.

How do I know which digit matters more for my environment, dust or water?

Both matter, but for different reasons. The first digit protects internal components from particulates that could interfere with operation, while the second digit addresses moisture that could cause corrosion or electrical failure. Match each digit to the specific exposure conditions your enclosure will actually face rather than treating the rating as a single number.