When we purchase any electrical equipment, mechanical devices, household instruments, or enclosures, it is important to identify what degree of IP rating or IP Code (Ingress Protection) the equipment offers. Ingress of solid or liquid particles into the equipment can be dangerous to humans as well as machinery.
The intention of this rating is to provide consumers and end users clearer details than advertising terminology such as "rainproof" or "waterproof."
Ingress Protection Codes and Classification
The IP code is used to stipulate the environmental protection used for specific equipment enclosure.
Normally an IP code has two numbers:
- Protection from solid particles
- Protection from liquids
As an example, with the rating "IP 23," the first digit "2" describes the level of protection from solid objects and second digit "3" describes the level of protection from liquids.
- 2 = Protected against solid objects up to 12mm, e.g. fingers.
- 3 = Protected against direct sprays of water up to 60° from the vertical.
An engineer working within industry should understand the types of enclosures provided against harzadous parts and the ingress of solid foreign particles for all equipment located in the plant. Also during design of machines, an engineer should take care of IP codes of equipment, considering its application and the surrounding condition of placement.
The applicable European standards for ingress protection are:
- BS EN 60529 Specification of Degrees of Protection Provided by Enclosures
- IEC 529 Specification of Degrees of Protection Provided by Enclosures
Both of these provide a numerical code to classify the degree of protection offered. Please click on the following link to view the table.
Ingress Protection Classification
First Numeral Degrees of protection against solid foreign objects ~Second Numeral degree of protection against water
IP Level ~Protection effective against solid. / IP Level ~Protection effective against liquid.
- 0 ~No Protection against contact and ingress of objects / 0 ~No Protection
- 1 ~Protection against large solid objects up to 50mm e.g. accidental touch by hand / 1 ~Protection against vertically falling drops of water e.g. condensation
- 2 ~Protection against solid objects up to 12 mm, e.g. fingers or similar objects/ 2~ Protection against direct sprays of water up to 15 deg tilted from the vertical
- 3 ~Protection against solid objects over 2.5 mm e.g. tools and thick conductors / 3 ~Protection against direct sprays of water up to 60 deg from the vertical
- 4 ~Protection against solid objects over 1 mm e.g. wires and screws / 4~ Protection against water sprayed from all directions – limited ingress permitted. i.e. Water splashing against the enclosure from any direction shall have no harmful effect.
- 5 ~Protection against dust – limited ingress (no harmful deposit) / 5 ~Protection against low pressure jets ( nozzle ) of water from all directions – limited ingress permitted 6 Total protection against dust
- 6 ~Protection against powerful jets of water against the enclosure from any direction shall have no harmful effects
- 7 ~Protection against the affects of immersion up to 1meter i.e. the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion).
- 8 ~Protection against long periods of immersion under pressure. It means the equipment shall be hermetically sealed.
European and North American Comparison
In North America, the NEMA (National Electrical Manufacturers Association) classification is used in preference to IEC (International Electro-technical Commission) codes. The IEC and NEMA degree of protection comparison is given below. The NEMA standard contains tests for environmental status like mechanical wear and tear, corrosion, etc.
NEMA EnclosureType Number ~Estimated IEC Code
- 1 ~IP 10
- 2 ~IP 11
- 3 ~IP 54
- 3R ~IP 14
- 3S ~IP 54
- 4 and 4X ~IP 56
- 5 ~IP 52
- 6 and 6P~ IP 67
An "X" is used for one of the letter if there is only one class of protection i.e. IP X3
Third Letter (Generally it’s omitted):
Ingress Protection rating may have additional third letter to classify the level of protection against mechanical impacts. This mechanical impact is defined by the energy required to qualify a specified resistance level (measured in Joules – J).
IP level ~Impact energy ~Equivalent drop mass and height
- 0 ~ –~ —
- 1 ~0.225 J ~150 g dropped from 15 cm
- 2 ~0.375 J ~250 g dropped from 15 cm
- 3 ~0.5 J ~250 g dropped from 20 cm
- 5 ~2 J~ 500 g dropped from 40 cm
- 7 ~6 J ~1.5 kg dropped from 40 cm
- 9 ~20 J ~5.0 kg dropped from 40 cm
Additional letters if defined can be classified the level of protection against access to hazardous parts by human:
Level ~Protection against access to hazardous parts like
- A ~Back of hand
- B ~Finger
- C ~Tool
- D ~Screw or Wire
Further letters shall be appended to classify additional details related to the protection of the equipment:
Letter ~Designated for
- H ~High voltage device
- M ~Object moving during water test
- S ~Object standing still during water test
- W ~Weather conditions
ContractorsUnlimited.co.uk: Ingress Protection IP Ratings (IP Codes)
Author's own experience as engineer at a steel plant.