Connectors have to be protected against the ingress of foreign materials such as moisture or dust.  This protection is provided for connectors their housing and the seal between the plug, receptacle, and cable. There is also a seal between receptacle and panel.  The degree of protection is defined by the IP standard. The standard IEC 60529 and/or DIN EN 60529 has specified the degree of protection and divided it into several levels. The degree of protection is defined by the IP number, which has the letters IP with two digits following.  The first digit defines the protection against the ingress of dust particles, the second digit defines the protection against the ingress of water. The table below shows the IP ratings for electrical connectors:

1st Digit Definition 2nd Digit Definition

0

No protection

0

No protection

1

Protected against access to hazardous parts with the back of a hand.  Protected against solid objects greater than 50 mm.

1

Protected against water drops

2

Protected against access to hazardous parts with a finger.  Protected against solid objects greater than 12.5 mm.

2

Protected against water drops when enclosure tilted up to 15

3

Protected against access to hazardous parts with a tool.  Protected against solid objects greater than 2.5 mm.

3

Protected against spraying water for 60 degree angle.

4

Protected against access to hazardous parts with a wire.  Protected against solid objects greater than on mm.

4

Protected against splashing water from all angles.

5

Protected against access to hazardous parts with a wire.  Dust-protected.

5

Protected against water jets from all angles.

6

Protected against access to hazardous parts with a wire.  Dust-tight.

6

Protected against powerful water jets and heavy seas.

7

Protected against the effects of temporary immersion in water.

8

Protected against the effects of continuous immersion in water under conditions which shall be agreed upon between manufacturer and user but which are more severe than for 7.

9K

Protected against water during high pressure/steam cleaning.