NEMA vs. IP ratings on Plastic Enclosures

Polycase® offers a variety of plastic waterproof enclosures that offer various NEMA and IP ratings, but what does that mean to you?

NEMA is an acronym for National Electrical Manufacturers Association. This organization gives enclosures ratings based on their protective qualities. NEMA ratings specify what type of environmental conditions it can withstand. The International Electrotechnical Commission (IEC) has developed an alternative rating system, the IP standard, which stands for Ingress Protection.

There is not a direct correlation between NEMA ratings and IP ratings, as the two systems are based on a different set of variables. IEC does not specify degrees of protection against mechanical damage of equipment, risk of explosions, or conditions such as moisture (for example moisture produced by condensation). However, the table below from www.nema.org shows an approximate cross reference that can be used to help determine the IP number that meets a particular NEMA rating.