Ingress Protection (IP) Ratings

What does IP stand for?
IP is an acronym for Ingress Protection

Why is Ingress Protection Important?
Liquid and/or solid particle ingress into electrical equipment may not only be harmful to the equipment, it may also be dangerous to the operator. Therefore when buying electrical equipment whether it be a transmitter, a switch, or a warning beacon it is essential to know what degree of ingress protection the item offers.

So how is Ingress Protection quoted?
An "IP" number, or as it is commonly known, an IP rating is used to specify the environmental protection offered. The IP rating is composed of two numbers, the first referring to the protection against solid object ingress and the second against liquid ingress. The higher the number the better the protection.

Are there standards covering these ratings?
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.

What are the numerical codes?
IP ratings

What do they use outside Europe?
In North America, the NEMA classification is used. NEMA (National Electrical Manufacturers Association) is a US trade association representing the interests of electroindustry manufacturers of products used in the generation, transmission and distribution, control, and end-use of electricity.

How does the IP and NEMA systems compare?
The IEC and NEMA degrees of protection can not be fully compared as equivalent ratings. The NEMA Standard includes tests for environmental conditions such as mechanical damage, corrosion, rusting, ice formation, etc. However the following table can be used as a guide:
NEMA to IP conversion

Does NEMA produce standards?
NEMA Standard Publication 250 and UL 40 Standard Publication both provide further information on ingress protection ratings used in the US.


Technical Library and Further Reading

For those who want to delve further into choosing electrical components and their installation, then the following may be of interest: