Watts are voltage multiplied by amperes and relate to the power consumption of an electrical device. The higher the watts, the more electricity is needed to power it. You pay for the amount of electricity you use in your home based upon the watts you use. The type of wire used to connect between your electrical device and the power supply must be able to carry the amount of current needed.
American Wire Gauge (AWG)
The type of wire needed to carry 500 and 1,000 watts is based upon a system known as the American Wire Gauge (AWG). To calculate the correct wire gauge for a 500 and 1,000 watt wire, you need to use the AWG system that is based upon amperes. You, therefore, need to know the amperes or current that will flow through a 500 and 1,000 watt wire. Domestic voltage in the United States is 110 volts, so to get the amperes you divide 500 by 110 to get 4.5 amperes then round it up to the nearest whole number to get 5 amperes. A wire that carries 1,000 watts has a current of 10 amperes. However, the distance between the power supply and the device also affects the wire gauge size. The longer the distance, the more resistance increases, meaning a larger wire gauge is necessary. For example, a wire carrying 500 watts, or 5 amperes, with a distance of 15 feet needs AWG 16 wire, while the same current flowing for 70 feet needs AWG 10 wire. Using the same distances, but for a wire carrying 1,000 watts or 10 amperes the wire gauges necessary are AWG 12 and AWG 6 respectively.
Thickness of Wire
Wire gauges in the United States are based on a numerical system. The lower the number, the thicker the cable, so the more watts it can safely carry. It, therefore, follows that wire capable of carrying 1,000 watts is thicker than wire made to carry 500 watts. Each wire gauge relates to the thickness of the wire. Using the same examples of distance, a 15-foot wire carrying 500 watts that requires AWG 16 wire has a diameter of 0.0508 inches, while a 30-foot wire carrying 500 watts that requires AWG 10 wire is 0.1019 inches thick. AWG 12 and AWG 6 wire is 0.0808 and 0.1620 inches thick respectively.
Number of Wires
A 500 watt wire is likely to be used to connect low-powered electrical items such as table lamps. Many lights do not need to be grounded, so a 500 watt wire may only have two internal wires: neutral and positive. However, a wire carrying 1,000 watts is likely to be powering a motorized device such as a washing machine. These items need to be wired to the ground, so a 1,000 watt wire will have three internal wires: ground, neutral and positive.
A device that consumes 500 watts uses 50 percent of the electricity needed to power a 1,000 watt device. Therefore, if you use a 500 watt device for one hour it will cost you half the money a 1,000 watt device will.
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