IP Ratings for solar junction boxes: IEC 529, IP 65, IP 67

The majority of solar junction boxes have at least an IP 65 rating, while the quality junction boxes have an IP 67 rating. This article explain the meaning of both IP 65 standard and the IP 67 standard and describes the IEC 529 standard as well.

IEC 529: Ingress Protection Standard

The International Electro-technical Commission (IEC), a globally recognized international standards and conformity assessment body, came up with a standard to define adequate protection of enclosures against the ingress of dust or water. The IEC 529 (BSEN60529:1991) standard codified the ingress tolerance of many enclosures and boxes used in electrical industry. The IP rating of an enclosure is a two digit numeric code that tells you how resistant a particular box is to dust and fluid ingress. IP is an acronym used for Ingress Protection. The rating consists of the IP abbreviation (IP) followed by a two digit code. Each digit represents the degree of tolerance against one of the environmental factors. T he first digit is the degree of tolerance against solid particles ingress while the second digit shows the same for liquid particle ingress.

 IP 65 and IP 67 rating for junction boxesIP 65 and IP 67 rating for junction boxes

Meaning of the digits used in an IP Code

The following tables clearly illustrate what the digits in the code stand for. Specific examples are also given for better understand of the degree of protection.

Table 1: Meaning of the first numeral in the IP Code
IndexProtection againstExamples
0No ProtectionNo Protection
1Large foreign bodies, diam. >50mmAccidental touch from the back of hand
2Medium-sized foreign bodies, diam. >12Touch by finger
3Small foreign bodies, diam. >2.5mmAccidental impact from tools and wires
4Granular foreign bodies, diam. >1mm
5Dust protectedDust deposits are permitted, but their volume must not affect the functioning
6Dust-proofComplete Protection

While Table 1 (above) lists specific protection against various forms of solid ingress, Table 2 (below) lists specific protection against various forms of liquid ingress.

Table 2: Meaning of the second numeral in the IP Code
IndexProtection against Examples
0No ProtectionNo Protection
1Water dripping/falling verticallyCondensation/Light rain
2Water sprayed at an angle (up to 15º degrees from the vertical)Light rain with wind
3Spray water (any direction up to 60º degrees from the vertical)Heavy rainstorm
4Spray water from all directions, (limited ingress permitted)Splashing
5Low pressure water jets from all directions, (limited ingress permitted)Hose down, residential
6High pressure jets from all directions, (limited ingress permitted)Hose down, commercial.e.g. Ship decks
7Temporary immersion, 15 cm to 1mImmersion in tank
8Permanent Immersion, under pressureFor use on Titanic recovery vehicle

Explanation IP 65 and IP 67o solar junction box IP Code

After understanding what each digit in the IP code stands for, let’s have a look at the most common IP ratings for solar junction boxes. Nowadays the majority of junction boxes have at least an IP65 ratings, while the quality junction boxes have an IP67 rating.

So what do IP65 and IP67 protection ratings mean?


IP=Ingress Protection against 6 = From Table 1, “Dust protection” 5 = From Table 2, “Low Pressure Water Jets from all directions” A junction box with a IP 65 rating will provide protection against Dust and Low pressure water jets. There may be limited ingress inside, but it won’t stop the component from properly functioning.


IP=Ingress Protection against 6 = From Table 1, “Dust protection” 7 = From Table 2, “Temporary immersion, 15cm to 1m.” This tells you that a solar junction box with an IP67 rating will provide complete protection against Dust and will properly function after Temporary immersion in water.



on 23 Feb 2019

what is the cost of IP67 approval versus IP65 approvals

Ranga Rao Naidu

Ranga Rao Naidu

on 18 Jan 2016

In IP65, second numeral defines water ingress when low power water jet is held on the box from all directions, and under such conditions, little ingress is permissible. How is the little ingress defined ?



on 20 Jan 2016

Hi Ranga, the second numeral 5 permits limited ingress and this limited ingress, not precisely quantified, must not have any harmful effects, so basically no harmful quanities of water shall ingress. Thus, when 12.5l/m of water jets at 30kPa pressure are projected against the box from any direction for minimum 3 minutes, the limited ingress of water (e.g. small drops) will not have any harmful effects in order for the enclosure to qualify for IPx5.



on 13 Jul 2016

From reliability perspective of PV modules, would you know the impact of humidity on ip65 v ip67; say after an accelerated humidity freeze test?



on 19 Jul 2016

When performing humidity freeze/ damp heat test on a certified module, the junction box should not have liquid ingress. There are plenty of modules on the market that carry certified IP65 rated junction boxes. So they can pass HF / DH chamber tests. However, why still go for IP65 rated junction boxes? IP67 junction boxes are more and more common and nowadays priced similarly as IP65 rated ones.

Place comment