IP 56 is a rating for enclosures that are subject to a variety of weather conditions. This is a standard developed by the International Electrotechnical Commission (IEC) and is a worldwide standard. In the U.S., the National Electrical Manufacturers ASsociation (NEMA) sets similar standards.

IEC Ingress Protection Standards

The IEC has a published standard 60529, which defines Ingress Protection using a two digit code. This standard has all the information about testing and applications.

The first digit indicates the protection against access to hazardous sections and whether solid objects can get into the encolosure. In other words, how hard is it to stick your finger in there and cause some trouble.

The second digit indicates the amount of protection against water.

Here are the designations for the first digit – Hazardous Parts:

0 – Non-protected
1 – Protected against access with the back of the hand (50mm size object)
2 – Protected against access with jointed finger (12 mm x 80 mm)
3 – Protected against acess with a tool (2.5 mm)
4, 5, 6 – Protected against access with a wire (1.0 mm)

Here are the designations for the first digit – Solid Foreign Objects:

0 – Non-protected
1 – Objects greater than 50mm
2 – Objects greater than 12.5 mm
3 – Objects greater than 2.5
4 – Objects greater than or equal to 1mm
5 – Dust protected
6 – Dust tight

Protection designation for the second digit – Ingress of Liquids

0 – Non-protected
1 – Water dripping vertically
2 – Water dripping, enclosure tilted up to 15d
3 – Spraying water, upt to 60d angle from vertical
4 – Splashing water, any direction
5 – Jetting water, any direction
6 – Powerful jetting water, any direction
7 – Temporary immersion in water
8 – Continuous immersion in water

You can see that an IP56 rated enclosure is protected against dust (and other small particles) and is water tight against jetting water from any direction.