AC Power Cords
AC power cords are detachable means of supplying alternating currents of electrical energy from a main power source to electrical equipment or appliances. Most
power cords are AC power cords, as there are many different possible types and voltages, depending on the country. AC power cords consist of a flexible cord with
electrical plugs at each end, one male and one female. Choices for male plugs include stripped hard wires, NEMA types and CEE types while choices for female plugs include IEC types, NEMA types and hard-wired terminals. NEMA type AC power cords are the standard for North American electrical plugs, cord voltage capacities and electrical receptacles' configuration; other regions throughout the world have different standards to which
cord sets adhere. AC power cords serve industries such as commercial, retail, industrial, residential, electronics and entertainment, with applications such as electrical power tools, lighting, household appliances, musical instruments, shop equipment and many personal uses.
AC power cords use alternating currents of electrical energy, movements or flows in which electric charges periodically reverse direction. This movement of energy transmits energy from a power supply source to equipment through a connecting cord. The connecting cord itself is a cable assembly comprised of a conducting medium, typically copper, surrounded by cord covers insulating material and an outer polymer or rubber jacket which protects the wire. AC power cord manufacturers follow various specifications in their construction, including voltage rating, current rating, wire shape and size, length and jacket material as well as the type of molded plug and female connector. The female connector attaches to the appliance or electrical equipment. The male plug connects the electrical receptacle, electrical outlet or power supply. The two most commonly used NEMA plug types are Type A, which have two conducting blades or prongs, and Type B, which have an additional third grounding rod. Both plug types are configured with a molded plastic body called a "jack" which holds the two blades apart, while the cord connects to the blades within the plug body. Inserting the blades into an electrical outlet, or receptacle, energizes the blades. An alternating current of electricity then flows through the blades, the blade-cord connection and the cord set, providing electricity to the equipment.
Different types of AC power cables are required for use depending on the country. Since many countries use different voltage and frequencies in their AC power, AC power cords must fit those standards in order to perform correctly. There are AC plug types A through M and the types can break down into further and further categories depending on slight variations in the plugs. For instance, IEC classes are one way of breaking the types down further by classifying the AC power cords based on whether they are grounded or ungrounded as well as the degree of insulation used. Grounding, or polarization, is especially important for certain higher voltage appliances and electrical equipment that could have a higher risk of electric shock when they become live. Polarization of an electric plug ensures that the equipment is connected to the neutral, or grounded, side of the circuit. Sensitive electrical equipment and products should only be used with polarized or grounding type AC power cords.