Leviton Catalog - Womack Electric Supply Company

TECHNICAL INFORMATIONTechnical InformationLeviton offers a complete selection of wallplates made of Type 302/304Non-Magnetic Stainless Steel. These wallplates are ideal for any applicationwhere magnetic interference must be avoided. Leviton’s CorrosionResistant wiring devices feature non-magnetic stainless steel assemblyscrews to ensure their suitability in marine applications. For health careapplications where non-magnetic devices are desired, Leviton’s CorrosionResistant devices should also be used.CO/ALR DevicesAluminum is used for residential wiring in Europe because it is a goodconductor and considerably cheaper than copper. Houses withaluminum wiring were built in the United States, but the practicestopped at least twenty years ago. It was discovered that poor connectionsbetween aluminum wire and steel or brass terminal screws ledto serious fires. There are still homes with aluminum wiring, and theNational Electrical Code stipulates that only CO/ALR devices are to beused in these applications.Aluminum wire tends to oxidize over time, and the oxide layer doesnot conduct electricity. This results in a poor connection with thewiring device terminal screws, particularly if they are steel. The connectionsgradually heat up to the point where fires are started insidethe walls. For this reason, all standard wiring devices contain thewarning, “For use with copper or copper-clad wire ONLY. Do not usewith aluminum wire.” The only exception to this are CO/ALR wiringdevices.Leviton offers a selection of CO/ALR devices for use with aluminumwire. In CO/ALR devices, the terminal screws are plating with the elementIndium. Indium is an extremely soft metal that forms a gassealedconnection with the aluminum wire, eliminating problemscaused by oxidation.Thermoset and Thermoplastic MaterialThere are significant benefits in using thermoplastics in wiring devicesinstead of thermosets. Each type of thermoplastic also has particularcharacteristics that may make it ideally suited for a specific application.Chemical Resistance of Materials Commonly Used in Wiring Devices*ThermosetsThermoset components are manufactured by compression molding,where powdered material is molded by heat and pressure. Thermosetmaterials cannot be remolded. The major types of thermoset materialsare Phenolic, Urea and Melamine. Phenolic is primarily used for darkcolors, while Urea is used for lighter colors.All thermoset materials provide dimensional stability when used inwiring devices. Phenolic is also a flame-resistant material. Thermosetsdo not provide a high degree of resistance to impacts, chemicals andsolvents, and therefore they are not suitable for heavy-duty applications.Thermosets are not used in Leviton Industrial Grade devices.Urea is still widely used to manufacture wallplates.ThermoplasticsThermoplastic components are manufactured by injection moldingwhere pellets of the material are heated to a liquid which can flow intoa mold. Unlike thermosets, thermoplastics can be remolded. Thesematerials are the preferred choice for heavy-duty applications becausethey provide superior resistance to impacts, chemicals and solventscompared to thermosets. The following is a list of the major types ofthermoplastic materials, along with some well-known brand names.■ Nylon: Zytel ® 101 Type 66 and Zytel Supertough ST 801 Type66■ Polycarbonate: Lexan ® , Calibre ® , Makrolon ®■ Polyester: Valox ® , Rynite ®■ ABS■ Acrylic■ PolypropyleneZytel ® and Rynite ® are registered trademaks of the Dupont Co.Lexan ® and Valox ® are registered trademaks of the General Electric Co.Calibre ® is a registered trademark of the Dow Chemical Co.Makrolon ® is a registered trademark of Bayer, Inc.CHEMICALSNylon Melamine Phenolic UreaPolyvinylChloridePolycarbonateRubber PolyesterPolypropyleneAcids C B B B A B B A AAlcohol A A A A A A B A ACausticBasesA B B B A C C B AGasoline A B A C A B B A AGrease A A A A A B B A AKerosene A A A A A B A A AOil A A A A A B A A ASolvents A A A A C C C B BWater A A A A A A B A AA – Completely resistant — Good to excellent for general use.B – Resistance is fair to good — Recommended for limited service.C – Slow attack. No recommended for use.Thermoplastic EnhancementsUV StabilityThermoplastics provide varying degrees of UV (Ultraviolet Light) stability.For example, standard grade nylon will lose tensile strength and durabilitywhen exposed to sunlight and weathering. Discoloring will also occur.There are additives that will increase the UV stability of thermoplastics.UV Stabilized thermoplastics should be used when a device is intendedfor extensive outdoor use. For example, Leviton uses UV- stabilized Lexanin their Raintight-While-In-Use Cover, with excellent results.Glass-Reinforced ThermoplasticsSeveral types of thermoplastics are available in glass-reinforced versions,including Rynite ® , Lexan ® , Valox ® and nylon. Glass reinforcementincreases the rigidity of the material and also raises the operating temperature.For example, Leviton Momentary and Maintained ContactSwitches feature glass-reinforced thermoplastic construction, makingthese switches ideally suited for rugged applications.V16To learn more about Leviton’s outstanding offering of devices visit our Website at: www.leviton.com