Enclosure Ratings and Material Types
Hartland Southwest works with two major manufacturers of electrical enclosures, Hammond Manufacturing and Allied Moulded Products. Hammond Manufacturing has been in existence since 1918 and their specialty is metal electrical enclosures and accessories. Allied Moulded Product began in 1958 and they are one of the nation’s largest non-metallic enclosure manufacturers. Both companies make product to UL and NEMA specifications.
Enclosures are typically rated to a UL type that allows the user to know whether it is an outdoor or indoor enclosure, and how well it is sealed from outside dust, water and other contaminants. Indoor enclosures are typically UL Type 1 or UL Type 12; UL Type 1 is used for commercial applications and UL Type 12 are intended for industrial applications. Likewise, outdoor enclosures are divided into commercial and industrial; UL Type 3R is commercial and UL Type 4 and 4X are industrial. There are other UL ratings but these are the ones that are most common. It is important to note that NEMA and UL type numbers are interchangeable, however, you should always look for the UL Type. UL requires inspection to insure that the enclosure meets the specification; NEMA does not require an inspection and there is no guarantee that the enclosure will perform as planned. One more thing on ratings – the “X” in UL Type 4X signifies corrosion resistance. With this rating, UL Type 4X enclosures will handle salty, acid, base and solvent environments.
Material types are also key in selecting an enclosure. Metal enclosures are used for UL Types, 1, 3R, 12, 4 and 4X. Non-metallic enclosures are most frequently rated at UL Type 4X. The reasons for this are simple. Metallic enclosures can easily be manufactured in any size and with whatever level of gasketing desired. This, along with different types of metal used (mild steel, stainless steel, aluminum), allow metal enclosures to cover all of the UL ratings. Non-metallic enclosures are typically molded and the molds are designed for gasketing to keep airborne contaminants and liquids out of the enclosure. In addition, the non-metallic materials, most often polycarbonate and FRP fiberglass reinforced polyester, are relatively resistant to chemicals and can easily pass the UL Type 4X corrosion test.
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Hammond Paint Maintenance and Touch-Up Painting
