Which protection class applies to the USA?
IP, NEMA or UL type rating - that is the question here. The right choice for applications in the USA must be well justified. What you absolutely need to know:
IP degrees of protection are identified in accordance with the international standard IEC 60529 with two code numbers and, if necessary, other supplementary letters for enclosures of electrical equipment and used worldwide - where North American standards do not apply.
For the North American region, NEMA protection classes are often required that cannot be transferred 1:1 to the IP system. Both the tests and the designations or markings differ considerably.
For use in the USA, products usually require UL approval (e.g. Industrial Control Panel according to UL508 A). For empty housings, the UL type rating, which is also shown on the nameplate, is of primary importance.
UL type rating and NEMA type rating are almost identical, as the NEMA specifications are the basis for the corresponding UL tests. The NEMA specification is the responsibility of the manufacturer, the UL rating is independently verified. This means that..: For enclosures not specifically intended for the North American market and for which UL approval is not required, the IP and NEMA specifications are correct. For enclosures with the required UL approval - regardless of the installation location - the UL type rating is correct.