From a manufacturing standpoint, electrical enclosures are rated according to how well they resist the ingress of certain types of materials – most notably water and detritus. For this purpose, there are two main standard scales – IP and NEMA. The latter was established and is updated by the National Electrical Manufacturers Association (NEMA) and the second is governed by the International Electrotechnical Commision (IEC).
The protocols for their testing vary to some degree but both aim to supply a certain level of security as to how well the electrical enclosure will perform under a variety of adverse circumstances. To reiterate, IP and NEMA ratings both define degrees of protection against substances such as water and dust, but use different parameters and methodologies to define their enclosure types (IEC standard 60529 and NEMA 250).
In particular, the 600+ published NEMA standards, cover everything from industrial-strength commercial enclosures to the ubiquitous two- and three-pronged wall plugs available in every home in the United States. Most notably, these safeties include a guarantee against access to the hazardous parts of the parts of the system as well as safeguards against the intrusion of water and other physical foreign objects such as dirt and dust.
IP ratings, on the other hand, are part of a worldwide standard. They are structured by the International Electrotechnical Commission (IEC), an international NGO (non-governmental organization) based in Geneva, Switzerland. “IP” actually stands for “international protection” but is more commonly known as “ingress protection.” There are dozens upon dozens of IP standards, but some of the most common ones are:
- IP54 - limited dust-tight and protected against water spray in any direction
- IP65 - dust-tight and protected against nozzle-projected water
- IP67 - dust-tight and protected against immersion
A Broader Overview
In general, the NEMA standards are geared towards industrial applications and are used primarily in North America. The IP ratings, however, cover a much broader set of applications on the worldwide stage. While NEMA includes other protection standards against atmospheric gasses (such as gasoline and acetylene) and corrosion resistance, IP ratings only cover protection against the ingress of solid objects and water.
There is no direct bi-directional conversion between NEMA ratings and IP ratings - However, NEMA type ratings offer a uni-directional IP rating equivalence. NEMA 250 also outlines a number of additional enclosure requirements, on top of dust and liquid ingress; some examples - NEMA requires functionality under icing conditions and testing for environmental hazards such as soil and corrosion, whereas IP standards do not.
For more information on NEMA and IP standards and how they impact your business, please contact us at EMTS. We can be found online at EMTS Lab or reached directly at 905-752-1925.