Grounding Electricity ExplainedOctober 2, 2010 • By The Internet Electrician
Grounding adds protection against electrical shock by ensuring that YOU or any other individual does not become a path through which electricity moves. This article reviews the reason for grounding electricity and why it is such an important safety and home electrical code compliance issue.
Basic Rules of Electricity
When working around electricity, there are some critical fundamentals that you need to be aware of. Electricity ALWAYS seeks the quickest path back to its source or to the earth. The process of grounding adds protection against electrical shock by ensuring that YOU or any other individual does not become a path through which electricity moves.
Proper grounding of electricity provides a safe path for electricity to safely move from a defective outlet, fixture, appliance or tool back into the earth, which happens to be a very good electrical conductor. Homes are grounded by either the use of ground electrodes (ground rods) or by ground plates. Another grounding option sometimes used is the home’s cold water supply pipe, providing that it is copper and is continuous to the water main. (Check local authority and code rules.)
Older homes may have polarized, rather than grounded receptacles. Replacing polarized receptacles requires adherence to code rules regarding proper grounding. If you live in an older home (pre 1960’s), you may have “polarized”, rather than grounded receptacles. Polarized receptacles operate on a 2-wire vs. a 3-wire system.
A polarized receptacle visibly differs from a grounded receptacle as they are two, rather than three-pronged. It is important to note that you cannot change a polarized receptacle to a 3-prong grounded receptacle without either grounding the outlet properly, or using a GFCI (Ground Fault Circuit Interrupter) receptacle. (Check with your local electrical authority and codes.)
What is the “Ground Wire”?
House wiring is color-coded, which allows you to distinguish between the “hot”, “neutral” and “ground” wires. The colors are standardized:
– Black or red for hot wires
– White for neutral wires
– Bare copper or green for ground wires
There are some significant differences between the neutral wire and the ground wire.
The neutral, or white wire, is responsible for transporting electricity back to a power source after it has passed through a load, or the device using the electricity (such as a light, fridge, stove, etc.). The ground, or copper or green wire, protects the system through the means identified above.
As a rule of thumb, remember that the ground wire should ALWAYS be the FIRST thing you hook up, and the last thing that you disconnect.