What is IP66??

What is an IP rating?
IP (or "Ingress Protection") ratings are defined in international standard EN 60529 (British BS EN 60529:1992, European IEC 60509:1989). They are used to define levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies (tools, dirt etc) and moisture.

What do the numbers in an IP Rating mean?
The numbers that follow IP each have a specific meaning. The first indicates the degree of protection (of people) from moving parts, as well as the protection of enclosed equipment from foreign bodies. The second defines the protection level that the enclosure enjoys from various forms of moisture (drips, sprays, submersion etc). The tables below should help make sense of it:

IP Ratings - what they mean.
IP Rated Enclosures - quick find chart
A number replaced by x indicates that the enclosure is not rated for that spec.

First Digit (intrusion protection)
No special protection<
Protection from a large part of the body such as a hand (but no protection from deliberate access); from solid objects greater than 50mm in diameter.
Protection against fingers or other object not greater than 80mm in length and 12mm in diameter.
Protection from entry by tools, wires etc, with a diameter of 2.5 mm or more.
Protection against solid bodies larger than 1mm (eg fine tools/small etc).
Protected against dust that may harm equipment.
Totally dust tight.
Second Digit (moisture protection)
No protection.
Protection against condensation
Protection against water droplets deflected up to 15° from vertical
Protected against spray up to 60° from vertical.
Protected against water spray from all directions.
Protection against low pressure water jets (all directions)
Protection against strong water jets and waves.
Protected against temporary immersion.
Protected against prolonged effects of immersion under pressure.
Our range
While we cover a huge range of electrical enclosures, our most common IP ratings are probably 65, 66, 67 and 68. So for quick reference, these are defined below:
IP65 Enclosure - IP rated as "dust tight" and protected against water projected from a nozzle.
IP66 Enclosure - IP rated as "dust tight" and protected against heavy seas or powerful jets of water.
IP 67 Enclosures - IP rated as "dust tight" and protected against immersion.
IP 68 Enclosures - IP rated as "dust tight" and protected against complete, continuous submersion in water.