IP Code
The protection of enclosures against ingress of dirt or water is defined in IEC 60529. Degrees of protection are most commonly expressed as 'IP' followed by two numbers e.g. IP67, where the numbers define the degree of protection.
The first number indicates the extent to which the equipment is protected against particles or users are protected from enclosed hazards. The second number indicates the extent of protection against water ingress;
First Figure
0 - No protection
1 - Protected against a solid object 50 mm or greater
2 - Protected against a solid object 12 mm or greater
3 - Protected against a solid object 2,5 mm or greater
4 - Protected against a solid object 1 mm or greater
5 - Dust protected
6 - Dust tight
Second Figure
0 - No protection
1 - Protected against vertically dripping water
2 - Protected against vertically dripping water, when tilted 15 degrees
3 - Protected against water spraying at an angle up to 60 degree
4 - Protected against water splashing from any direction
5 - Protected against jets of water from any directions
6 - Protected against powerful jets of water from any directions
7 - Protected against immersion between a depth of 150 mm and 1000 mm
8 - Protected against submersion
IP (IEC) / NEMA 250 Standard correlations
IEC 60529 - NEMA 250
IP10 - NEMA 1
IP11 - NEMA 2
IP54 - NEMA 3 R
IP52 - NEMA 5-12-12 K
IP54 - NEMA 3-3 S
IP56 - NEMA 4-4 X
IP67 - NEMA 6-6 P