In 1961, Charles Dalziel, professor of electrical engineering at the University of California, invented the ground-fault circuit interrupter (GFCI). Today, GFCIs are required by the National Electric Code in all new kitchens, bathrooms, crawl spaces, unfinished basements, and most outdoor receptacles.
Here is why:
A ground fault happens whenever electricity escapes the confines of the wiring in an appliance, light fixture, or power tool and takes a shortcut to the ground. When that shortcut is through a human, the results can be deadly. About 200 people in the U.S. alone die of ground faults each year, accounting for two-thirds of all electrocutions occurring in homes.
Most of the time, a GFCI does nothing; it just monitors the difference in the current flowing into and out of a tool or appliance. But when that difference exceeds 5 milliamps, an indication that a ground fault may be occurring, the GFCI shuts off the flow in an instant — as little as .025 second. GFCIs protect you whether or not your wiring is grounded.
You should test your GFCIs monthly because lightning and other power surges can damage a GFCIs delicate circuitry at any time. Just plug in a light fixture and turn it on. Then push the device’s test button. If the light stays on, the GFCI needs to be replaced.
Oak Electric Service is one of southeast Michigan’s leading electrical and renewable energy contractors. Give us a call at (800) 964-7070. We are standing by to answer all of your residential and commercial electrical questions. We will always personally answer your phone call – you will never reach an answering service! Be sure to ask about our “Free Electrical Safety Inspection” with every job. We invite you to visit our website at www.oakelectric.com to learn more about us.