The correlation between NEMA Standards and IP Ratings is in constant question. In the late 1990’s European IP ratings for enclosures, wiring devices, and fittings started their influx due to the demand of European products becoming predominant. Additionally, US OEM’s were in question for their equipment being built for the European and World Market. NEMA vs IP, UL vs ETL, even CEENorms all came into play.
There are two major electrical manufacturing organizations monitoring product enclosures and/or their degree of protection; each organization also publishes technical manufacturing standards. The National Electrical Manufacturers Association (NEMA) Standard 250-2003 addresses non-hazardous locations, enclosure design, and environmental performance requirements. These are referred to as NEMA Types. (www.nema.org)
The International Electrotechnical Commission (IEC) 60529 Standard addresses Ingress Protection (IP); this describes the degree of protection provided, not the enclosure itself. The first digit of the IP Code designation describes the degree of protection against the ingress of solids; the second digit designates the degree of protection against the ingress of liquids. IP Codes support NEMA Type designations. (www.iec.ch)
The following information is taken from both electrical industry Standards; it matches NEMA Ratings with its IP counterpart, with a brief description of each rating. It is provided as a guideline for the NEMA vs IP ratings on enclosures. Which eventually incorporate electrical fittings tested under UL 514B NEMA FB1. It is a guideline, specific testing is not endorsed in this chart.