IP65 vs IP67 Rating

What IP ratings mean

IP (Ingress Protection) ratings are an internationally recognised system for specifying the protection that an electrical enclosure provides against external environmental factors. The system is defined by IEC 60529 and consists of a two-digit code following the letters “IP”.

The first digit (0 to 6) specifies protection against solid objects (dust, dirt, accidental contact).

The second digit (0 to 9) specifies protection against liquids (water spray, water jets, immersion).

For solar applications, the relevant ratings are:

IP65: Dust-tight + protected against water jets.

IP66: Dust-tight + protected against powerful water jets.

IP67: Dust-tight + protected against temporary immersion (up to 1 metre, 30 minutes).

IP68: Dust-tight + protected against continuous immersion under manufacturer-specified conditions.

Higher numbers in the second digit indicate better water protection.

Detailed IP rating definitions

The first digit (solid protection):

0: No protection.

1: Protected against objects larger than 50 mm.

2: Protected against objects larger than 12.5 mm.

3: Protected against objects larger than 2.5 mm.

4: Protected against objects larger than 1 mm.

5: Dust-protected (limited dust ingress, not preventing operation).

6: Dust-tight (no dust ingress).

The second digit (liquid protection):

0: No protection.

1: Protected against vertically dripping water.

2: Protected against dripping water at 15-degree tilt.

3: Protected against water spray up to 60-degree from vertical.

4: Protected against splashing water from any direction.

5: Protected against water jets from any direction (12.5 L/min, 6.3 mm nozzle, 3 metre distance).

6: Protected against powerful water jets (100 L/min, 12.5 mm nozzle, 3 metre distance).

7: Protected against temporary immersion (1 metre depth, 30 minutes).

8: Protected against continuous immersion (depth and duration specified by manufacturer).

9: Protected against high-temperature, high-pressure water (for industrial cleaning).

For solar applications, the second digit of interest is typically 5, 6, or 7.

IP65 in detail

IP65 is the most common rating for outdoor solar inverters. It provides:

Complete protection against dust ingress.

Protection against rainfall and outdoor water spray.

Tested by directing a 12.5 L/min water jet from 3 metre distance for 3 minutes from any direction.

Suitable for installations where:

The component is mounted outdoors.

It will experience rainfall and possibly intentional cleaning with water jets.

It will not be submerged.

For most rooftop and ground-mount installations in India, IP65 inverters provide adequate protection.

IP67 in detail

IP67 is common for solar connectors (MC4) and junction boxes. It provides:

Complete protection against dust ingress.

Protection against temporary immersion in 1 metre of water for 30 minutes.

Suitable for installations where:

The component may experience flooding (low-lying rooftops, ground-mount in monsoon-affected areas).

The component is in a location with high humidity and condensation.

Long-term outdoor exposure with potential for occasional submersion.

For solar connectors that may sit in puddles on flat rooftops or in ground-mount installations, IP67 provides necessary protection.

IP rating selection for solar components

The rating choice for each component matches its expected operating environment.

IP rating degradation

IP ratings apply to the enclosure as designed and manufactured. Field conditions can degrade the effective rating:

Damaged enclosure: Cracks, holes, or scratches reduce protection.

Failed seals: Rubber gaskets and silicone seals degrade with age and UV exposure.

Improper installation: Wrong torque on screws, missing washers, or damaged cable glands compromise sealing.

Cable damage: Damaged cable insulation can allow water ingress through the cable entry.

Annual inspection of solar components helps catch IP rating degradation. Damaged enclosures and worn seals should be replaced before catastrophic failure.

IP rating versus NEMA

In North America, the NEMA rating system is used instead of IP. The two systems are not directly equivalent but overlap:

NEMA 4: Roughly equivalent to IP66.

NEMA 4X: Includes corrosion resistance, no IP equivalent.

NEMA 6: Roughly equivalent to IP67.

NEMA 6P: Continuous immersion, equivalent to IP68.

For solar applications in India, IP ratings are used. International products may carry both IP and NEMA ratings.

Common mistakes regarding IP ratings

Treating IP ratings as absolute. Field conditions can degrade ratings; periodic inspection is needed.

Specifying too-low IP rating. Inadequate protection causes premature component failure.

Specifying too-high IP rating. Unnecessary cost increase.

Confusing first and second digits. IP56 (dust-protected + powerful jets) differs from IP65 (dust-tight + ordinary jets).

Ignoring cable entry protection. The enclosure may be IP67, but cable gland failure compromises overall protection.

Mismatching component ratings. The whole installation is limited by the lowest-rated component.

Best practices

For solar inverter selection: specify IP65 minimum for outdoor mounting.

For MC4 connectors: specify IP67 minimum.

For junction boxes: verify the manufacturer’s IP rating (typically IP67 or IP68).

For cable glands: use proper IP-rated glands matched to the enclosure.

For coastal Indian installations: consider corrosion-resistant materials in addition to IP rating.

For high-humidity environments: prefer higher IP ratings (IP66 or IP67 for inverters).

Standards and references

IP ratings are defined by IEC 60529, adopted by BIS as IS 13947. Solar components are tested per IEC 60529 to verify their IP ratings. Specific solar standards (IEC 61215, IEC 61730, IEC 62109) reference IP ratings for various components.

Related glossary terms

• Junction Box
• MC4 Connector
• String Inverter
• Hybrid Inverter
• Microinverter
• String Combiner Box (SCB)
• IEC 61730 Standard

Key takeaways

IP (Ingress Protection) ratings define how well solar components are protected against dust and water. IP65 means dust-tight and protected against water jets, common for outdoor inverters. IP67 means dust-tight and protected against temporary immersion, common for MC4 connectors and junction boxes. IP68 means continuous immersion protection. For Indian solar installations, IP65 is the minimum for outdoor inverters; IP67 is preferred for connectors and junction boxes; coastal sites benefit from higher ratings. Annual inspection helps maintain effective IP rating throughout the system’s life.