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POWER CORDS
AC power cords carry alternating current from one area to another. There are many different standard plugs and voltages, depending upon the country. These cords are a conducting medium, usually copper, that is surrounded by insulation and a jacket. Power cords can have 2, 3, or 4 conductors. Choices for male end types include NEMA types, hardwired stripped types, hard wired terminals, CEE, BS, JIS, AS, SRAF, SEV, CEI, SI, and BS types.
| The National Electrical Manufacturers Association (NEMA) sets standards for AC power cord male ends. The male end can also be stripped hard wires, hard wires with terminals, European ends, UK specific ends, and many other country specific types. The polarization for male end types can be polarized or nonpolarized. A polarized end fits only one way; a nonpolarized end fits both ways. Female end types include NEMA, hard-wired stripped, hard-wired terminals, and IEC types. The National Electrical Manufacturers Association (NEMA) sets standards for AC power cord female ends. The female end can also be stripped hard wires and hard wires with terminals. The International Electrotechnical Commission (IEC) sets standards for European female ends. Important physical specifications to consider when searching for AC power cords include cord length, wire shape, jacket material, hospital grade, maximum cable temperature, rated current, and rated voltage. The cord length is the length of the cord including connectors. Wire shape is flat or round. Choices for jacket material include PVC, rubber, polychloropene rubber, and textile construction. All power cords have an outer jacket to protect and insulate the wire. Polyvinyl chloride is used in offices, domestic premises, kitchens, household appliances, refrigerators, etc. They are unsuitable for outdoor use. The rubber jacket is used when cable subjected to mechanical stresses in dry and damp areas. Use as power for transportable motors, appliances, and electric tools such as circular saws, and agricultural use. A polychloropene rubber jacket is more thermally stable then a rubber jacket. Textile construction jackets are durable. Power cords going into any hospital application are subject to special requirements by Underwriters Laboratories (UL). The entire cord is tested by a method that destroys the cord if it fails any portion of the test. Maximum cable temperature is the recommended operating temperature for the wire. The rated current is the rated amperage of the cord. The rated voltage is specified in volts. Common approvals for AC power cords include CSA Mark (US, C, and US, NRTL/C), SAA, UL Listing mark, and UL Recognized Component Mark. The CSA Mark may appear alone or with indicators. If it appears alone, it means that the product is certified for the Canadian market, to the applicable Canadian standards. If this Mark appears with the indicator "C and US" or "NRTL/C" it means that the product is certified for both the U.S. and Canadian markets, to the applicable U.S. and Canadian standards. Standards Australia is the trading name of the Standards Association of Australia (SAA), an independent not for profit organization whose primary role is to prepare, publish and maintain Australian Standards. Standards Australia evolved from the Commonwealth Engineering Standards Association. The UL Mark denotes that Underwriters Laboratories Inc. (UL) has found that samples of the product met UL's safety requirements. These requirements are primarily based on UL's published Standards for Safety. UL Recognized Component Marks are used only on component parts that are part of a larger product or system. These components may have restrictions on their performance or may be incomplete in construction. Products intended for Canada carry the Recognized Component Mark "C."
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