The IP code (or International Protection Rating, sometimes also called Ingress Protection Rating) consists of the letters IP followed by two digits and an optional letter. As defined in International standards [IEC 60529 (Ed. 2.1), clause 4.1], it classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact and water in electrical enclosures.

The National Electrical Manufacturer Association (NEMA) defines standards for various grades of electrical enclosures and the types of environments in which they can be used. These classifications are obtained by doing specific tests in a lab to ensure that the device meets the required specifications. Other factors such as corrosion protection and construction details are involved in the NEMA system.

CETCI’s products are tested to the IP54 International standards. The numbers that follow the letters ‘IP’ have specific meanings. In the case of IP54, 5 means protected against dust that may harm equipment and 4 means protected against water spray from all directions. CETCI enclosures that have a sensor vent covered by a splash guard are IP54 rated. Enclosures that do not have a sensor vent, but have a door mounted water tight buzzer are IP54 rated.

Unlike many things that can be converted such as kilometers and miles or Celsius and Fahrenheit, there is no direct formulaic correspondence between NEMA types and IP ratings.  According to the document ‘NEMA FAQs: Enclosures’, it is not possible to state that an IP rating is equivalent to a NEMA type designation. An IP rating only considers protection against ingress of solid foreign objects (dust) and ingress of water. The NEMA types consider these but also consider other factors such as corrosion resistance, construction details and use in atmospheres containing explosive agents. For this reason, it is possible to say that a NEMA type is equivalent to an IP rating, but it is not possible to state that an IP rating is equivalent to a NEMA type.

References
IEC 60529 (Ed 2.1), clause 4.1
IP (Ingress Protection) Rating Guide. Courtesy of gulfradiant.com Retrieved from https://www.nemaenclosures.com/media/catalog/category/ratings/NE_IP_Reference_Chart_0614.pdf
IP Rating Chart Retrieved from http://www.dsmt.com/resources/ip-rating-chart/
APPROXIMATE CONVERSIONS OF NEMA ENCLOSURE TYPES TO IP CLASSIFICATION DESIGNATIONS. Retrieved from https://www.guardiantelecom.com/resources/knowledgebase/approximate-conversions/