Wenatchee and Chelan Home Inspections- How GFCI circuits protect you

Submitted by DonHester on Thu, 11/04/2010 - 09:28.

How GFCI circuits protect you! Wenatchee and Chelan Home Inspections

GFCI (Ground Fault Circuit Interupter)- How does it work?

Basic electrical principle for lay people (me included ; ) - This is only to give a very basic analogy of how electricity works.

Think of electricity as water (electrons) flowing (current) through a pipe (wires). Electricity moves at the speed of light (186,000 miles per sec). So it takes 0.0000053 seconds for electricity to move a mile. If you have a valve (switch) on the pipe and you close it you will have no flow(current), no water(electrons).

Now to really make it fuzzy, the electricity in the modern grid is AC (alternating current), so it changes direction 120 times a second.

For the electricity to produce an effect (shock, heat, light or mechanical work (a motor)) it has to have a complete circuit. Electricity has to flow. No complete circuit, no flow, no electrical effect.

Example (simple one): if I grab the hot wire (energized) and I am not a ground path (no flow) I will not get shocked (do not try this at home this is just an example!). I can only be shocked if I provide a means for the electricity to flow.

This is how trained electricians can work on energized electrical systems and not get shocked. They have to ensure there is no way for them to produce a complete circuit and they must be isolated.

Disclaimer- I not going into the physics of how you have strong enough electrical field air can be a conductor.

Now for the GFCI-

When the amount of electrical current (flow) coming out of the 'hot/energized' slot of the outlet/receptacle (the small slot) is just about 5/1000 of an amp (5 milliamp) different from the amount of electrical current returning back to the outlet/receptacle on the 'neutral' slot (the larger slot), the outlet will 'trip', i.e. shut off the power. The GFCI outlet circuit senses that it is putting out more electricity than it is getting back, causing an imbalance. The GFCI circuit assumes this missing electrical current can be going is to another source of ground, which may be you! This is how a GFCI protects you.

When performing a home inspection I will always suggest upgrading to GFCI (I am also require to) in the appropriate areas where missing. I am not worried about the home being grandfathered to an older standard. This is a safety issue and an inexpensive, easy fix.

Here is a chart on when GFCI protection was required by location (2008 code)-

Wenatchee and Chelan Home Inspections- How GFCI circuits protect you

Ancora Imparo

NCW Home Inspections, LLC is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…

Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service

www.ncwhomeinspections.com 509-670-9572

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Wenatchee and Chelan Home Inspections- How GFCI circuits protect you