If you need to plug an extension cord into a convenience outlet on a modern fluorescent light fixture, it seems like no big deal. However, these modern conveniences were not available until the 20th Century. In fact, the electrical outlet has an interesting history, which may make you appreciate it a little more.
In the Early Days
In the mid-Seventeenth Century, electric motors were used mostly for experiments. However, by the end of the Nineteenth Century, electric motors had helped to usher in the age of the Industrial Revolution. Electrical devices were showing up everywhere in the late Nineteenth Century, including a marvelous invention which toasted your bread using the power of electricity.
Separate Attachment Plug
By the 1890s you could use plugs designed to screw into lamp sockets, and some had two simple pins. Yet, in 1903, a man named Hubbell revolutionized the electrical appliance industry with his separate attachment plug. Before then, it was often inconvenient to use an electrical receptacle or convenience outlet.
Even though grounded receptacles did not become common in homes until the mid-1960s, they have been around since a man named Knapp filed his patent for an “earthed” receptacle in 1911. The basic configuration is still seen today in things like the modern convenience outlet, which lets you plug grounded devices into light fixtures.
Fact about Neutral and Grounded Conductors
Did you know the white and bare wires on a typical receptacle are both grounded to the same busbar in your breaker panel? However, they serve different purposes. The bare (or green) wire is not a current carrying conductor. It is designed to ground the metal chassis of an appliance. If there is a fault in the circuit, it causes a short circuit and trips the circuit breaker. This prevents you from getting a shock when you touch the appliance.