Technical appendix NEMA 250-2003 to IEC 60529 enclosure classification designations (IP) (Cannot be Used to Convert IEC Classification Designations to NEMA Type Ratings) IP First IP Second NEMA Enclosure Type Character Character 3, 3X, 1 2 3R, 3RX 4, 4X 5 6 6P 12, 12K, 13 3S, 3SX IP0_ IP_0 IP1_ IP_1 IP2_ IP_2 IP3_ IP_3 IP4_ IP_4 IP5_ IP_5 IP6_ IP_6 IP_7 IP_8 A B A B A B A B A B A B A B A B A B A = A shaded block in the "A" column indicates that the NEMA B = A shaded block in the "B" column indicates that the NEMA Enclosure Type exceeds the requirements for the respective Enclosure Type exceeds the requirements for the respective IEC IEC 60529 IP First Character Designation. The IP First Character 60529 IP Second Character Designation. The IP Second Character Designation is the protection against access to hazardous parts and Designation is the protection against the ingress of water. solid foreign objects. Example Of Table Use Type requires an outdoor corrosion test; a gasket aging test; a dust An IEC IP 45 Enclosure Rating is specified. What NEMA Type test; an external icing test; and no water penetration in the rain test. Enclosures meet and exceed the IP 45 rating? Slight differences exist between the IEC and NEMA test methods, but the IEC rating permits the penetration of water if "it does not Referencing the first character, 4, in the IP rating and the row deposit on insulation parts, or reach live parts." The IEC rating does designated "IP4_" in the left most column in the table; the blocks in not require a corrosion test; gasket aging test; dust test or external Column "A" for NEMA Types 3, 3X, 3S, 3SX, 4, 4X, 5, 6, 6P, 12, 12K, icing test. Because the NEMA ratings include additional test and 13 are shaded. These NEMA ratings meet and exceed the IEC requirements, this table cannot be used to select IP Designations protection requirements against access to hazardous parts and solid for NEMA rated enclosure specifications. foreign objects. IEC 60529 specifies that an enclosure shall not only be Referencing the second character, 5, in the IP rating and the row designated with a stated degree of protection indicated by the first designated "IP_5" in the right most column in the table; the blocks characteristic numeral if it also complies with all lower degrees of in Column "B" for NEMA Types 3, 3X, 3S, 3SX, 4, 4X, 6 and 6P are protection. Furthermore IEC 60529 states that an enclosure shall shaded. These NEMA ratings meet and exceed the IEC requirements only be designated with a degree of protection indicated by the for protection against the ingress of water. The absence of shading second characteristic numeral if it also complies with all lower in Column "B" beneath the "NEMA Enclosure Type 5" indicates that degrees of protection up to and including the second characteristic Type 5 does not meet the IP 45 protection requirements against numeral 6. An enclosure designated with a second characteristic the ingress of water. Likewise the absence of shading in Column numeral 7 or 8 only is considered unsuitable for exposure to water "B" for NEMA Type 12, 12K and 13 enclosures indicates that these jets (designated by second characteristic numeral 5 or 6) and enclosures do not meet the IP 45 requirements for protection against need not comply with requirements for numeral 5 or 6 unless it is the ingress of water. Only Types 3, 3X, 3S, 3SX, 4, 4X, 6, and 6P have dual coded. Since the IEC protection requirements become more both Column "A" in the "IP4_" row and Column "B" in the "IP_5" row stringent with increasing IP character value up through 6, once a shaded and could be used in an IP45 application. NEMA Type rating meets the requirements for an IP designation The NEMA Enclosure Type 3 not only meets the IP 45 Enclosure up through 6, it will also meet the requirements for all lower IP Rating, but also exceeds the IEC requirements because the NEMA designations. This is apparent from the shaded areas shown in the table. Note Reprinted with permission from National Electrical Manufacturers Association, exert from NEMA 250-2003 pages 28 – 29. 840 Rittal Catalog 33
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