IP68 Electrical Enclosures and Junction Boxes: What They Are and When to Use Them

IP68-rated electrical enclosures and junction boxes are designed to prevent water ingress during immersion under defined conditions.

• IP68 enclosures: Protect internal components in environments where immersion or water intrusion is a risk

• IP68 junction boxes: Seal electrical connections in environments where water intrusion is a risk

• Typical use: Applications involving flooding, standing water, or below-grade installations

IP68 does not mean “universally waterproof.” IP68 confirms that an enclosure can be submerged, but it does not define a single depth or duration. Those limits are set by the manufacturer.

What IP68 Means in Electrical Enclosures and Junction Boxes

IP68 is a part of the Ingress Protection (IP) rating system, which classifies how well an enclosure prevents solids and liquids from entering. The “6” indicates complete protection against dust. The “8” indicates protection against water during immersion. Unlike lower water ratings, IP68 is not limited to splashing or spray. It applies when the enclosure is expected to be submerged.

However, IP68 is not a single, fixed rating. The depth and duration of immersion vary depending on how the enclosure is tested. This means two IP68 enclosures may be rated for different immersion conditions, even though they share the same classification. The exact depth and duration of submersion are specified by manufacturer-defined test parameters.

Two enclosures can both be rated IP68 and still be tested to different immersion conditions.

IP68 Enclosures vs IP68 Junction Boxes

IP68 applies to both full enclosures and junction boxes, but their roles are different.

IP68 Enclosures

These are larger housings designed to protect complete systems or components.

They are typically used to:

• Protect control systems or instrumentation

• House electrical equipment in wet or submerged environments

• Maintain environmental separation in outdoor or below-grade installations

IP68 Junction Boxes

These are smaller, purpose-built enclosures designed to protect electrical connections. They are used to:

• Seal cable entry points

• Protect splices and terminations

• Maintain connection integrity in wet or submerged conditions

While both use the same rating, junction boxes are focused specifically on protecting connections, not complete systems.

When IP68 Protection Is Required

IP68 is typically required when water exposure includes the possibility of immersion. Common scenarios include:

• Underground installations

• Flood-prone environments

• Marine and coastal applications

• Wastewater and pump systems

• Infrastructure exposed to standing water

In these applications, the enclosure must maintain a seal while surrounded by water.

For a broader overview of submersible enclosure design and performance, see What is a Submersible Electrical Enclosure?

When IP68 May Not Be Necessary

IP68 is often over-specified when the environment does not involve immersion.

It may not be required for:

• Rain exposure

• Occasional spray

• Washdown conditions

In these cases, selecting a lower rating can:

• Reduce cost

• Simplify installation

• Avoid unnecessary design complexity

The correct choice depends on actual exposure conditions, not assumed risk.

IP68 vs Other Waterproof Ratings

IP68 represents the highest level of water ingress protection within the IP rating system. However, it should be evaluated alongside other rating systems when specifying enclosures. For example, NEMA 6 applies to temporary submersion, and NEMA 6P applies to prolonged immersion. IP68 is comparable to NEMA 6P in that regard.

For a full comparison of submersion ratings and how they apply in the field, see NEMA 6 vs NEMA 6P: Differences in Submersible Enclosure Protection.

Where IP68 Solutions Are Commonly Used

IP68 enclosures and junction boxes are used in environments where water exposure is expected, not incidental.

These include:

• Infrastructure and utility systems

• Marine installations

• Industrial and environmental applications

• Underground and below-grade systems

In these environments, failure is typically caused by immersion, not surface exposure.

Frequently Asked Questions (FAQs)

What's the difference between an IP68 enclosure and an IP68 junction box?

IP68 enclosures are larger housings designed to protect complete systems or components, such as control systems or instrumentation. IP68 junction boxes are smaller, purpose-built enclosures focused specifically on protecting electrical connections, including cable entry points, splices, and terminations.

Does IP68 guarantee a specific depth or duration of submersion?

No. IP68 confirms that an enclosure can be submerged, but it does not define a single depth or duration. Those limits are set by the manufacturer and specified through individual test parameters.

When might IP68 be over-specified for an application?

IP68 may not be necessary for rain exposure, occasional spray, or washdown conditions. In these cases, selecting a lower rating can reduce cost, simplify installation, and avoid unnecessary design complexity.

Can two IP68-rated enclosures perform differently under water?

Yes. IP68 is not a single, fixed rating. Because depth and duration of immersion are set by manufacturer-defined test parameters, two enclosures can both carry an IP68 rating while being tested to different immersion conditions.

What environments typically require IP68 protection?

IP68 is typically required for underground installations, flood-prone environments, marine and coastal applications, wastewater and pump systems, and infrastructure exposed to standing water.