WHAT YOU NEED TO KNOW

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Voltage drop is an important part of electricity. In an earlier video we talked about wire ampacity. We said that if you have a 15 amp breaker you need to use a 14 gage wire. This is generally true unless you are dealing with continuous loads or long wire runs. If you are trying to power a receptacle in your shed that is 300 feet from your house. Then using 14 gage wire will not work.

The longer the wire run, the more resistance you get. If you have too much resistance, your outlet may not get the 120 volts it needs to properly power your electrical device. A good rule of thumb to use is, for every 100 feet of wire, you need to upsize your wire one wire size. So if your receptacle is 300 feet from your house you need to use number 8 AWG instead of number 14 AWG. This lets the voltage flow with less resistance and will give you a more efficient electrical circuit.

A lot of people use the garden hose analogy when explaining voltage drop. If you have a 25 foot hose, and and a 100 foot hose, and you turn on the water at the same pressure, the water is going to flow a lot faster at the 25 foot hose. There is a lot more resistance for the water to flow through a 100 feet of hose. The same is true with electricity.