Answer to Question 11.

11. What are IP ratings?

IP ratings are an internationally approved numerical system used for specifying the protection level of an enclosure or housing, against the ingress of solid objects & liquid. The first digit represents the degree of protection against dust, the second, moisture.

Dust 0 No Protection   Moisture 0 No Protection
Dust 1 Protected against solid objects Greater than 50mm. E.g. Hand.   Moisture 1 Dripping water shall have no harmful effect.
Dust 2 Protected against solid objects Greater than 12mm. E.g. fingers.   Moisture 2 Protected against dripping water when enclosure is tilted 15 degrees.
Dust 3 Protected against solid objects Greater than 2.5mm. E.g. tools.   Moisture 3 Protected against spraying water up to 60 degrees.
Dust 4 Protected against solid objects Greater than 1mm. E.g. wires.   Moisture 4 Water splashed from any direction shall have no harmful effect.
Dust 5 Ingress of dust is not totally protected but does no enter in sufficient quantities to harm equipment.   Moisture 5 Water hosed against the enclosure shall have no harmful effect. (Water jets)
Dust 6 No ingress of dust.   Moisture 6 Water from powerful jets or heavy seas shall have no harmful effect.