Another safety feature built into outlets is the GFCI. I’m sure you have seen or own those outlets with two buttons on them, one reading TEST and the other RESET. We often get questions about these. What do they do, how do they work, and why are they used? These questions were a large part of the inspiration for this post: it turns out a lot of people are wondering what exactly these buttons do.
I have heard many theories over the years about the nature of these buttons, and how we are to use them. I have had people tell me all sorts of strange things about these buttons. However, what they do is actually pretty simple. The buttons are part of a GFCI, or Ground Fault Circuit Interrupter. They are designed to prevent electrical accidents, much like fuses. However, while fuses are mostly used to prevent fires, GFCIs are used to sense flow of current. The classic example of an electrical hazard is the dropping of a hair dryer into a bathtub. This will create an opportunity for the current from your outlet to do damage to anyone in contact with the water, as the current takes shortcuts to the ground. However, a GFCI will sense that more electricity is flowing out than is returning. This means that there is a fault, and electricity is discharging somewhere unintentional. In a fraction of a second, the GFCI will interrupt the flow of electricity, potentially saving lives.
But what do the buttons do? The buttons are designed to give peace of mind to the owner of the circuit. They give an easy way to check that the safety measures are still working as intended. To test, plug something in and turn it on. Then, press the test button. If the GFCI is working, the circuit will interrupt the flow of power, and whatever you plugged in should turn off. Then, you can press the reset button to return the outlet to its normal functionality.
So, there you have it. These outlets should not be a mystery. They are one of the many safety features that we have built into our lives that we may not even notice. So, take the time to appreciate the effort and engineering that has gone into making our lives safer and more convenient. And if you have some GFCIs, go test them out. If they are not working, it could be a sign that you need some electrical work done.