Ground wire installation in San Antonio

A ground wire gives fault current a safe way home. When a hot wire touches a metal box or an appliance case, the ground carries that current back to the panel fast enough to trip the breaker, rather than leaving the metal energized for the next person who touches it.

A grounding system has several parts, and any of them can be missing in an older home. At the service, ground rods driven into the soil are tied to the panel by a grounding electrode conductor. Metal water piping and gas piping are bonded so they sit at the same potential as the electrical system. Each branch circuit then carries its own equipment ground to every outlet and fixture on it.

Two prong outlets are the sign most people notice. Homes wired before grounded circuits became standard often have no ground wire to the outlets at all, and a three prong adapter does not supply one. A three prong outlet on a two wire circuit with no ground is a common inspection finding, because it looks grounded and is not.

Code allows two answers. One is to run a ground wire or a new grounded circuit to the outlets, which gives true grounding for surge strips and electronics. The other, where new wire is not practical, is GFCI protection, with each outlet labeled to show it has no equipment ground. We explain both and price the one you choose.

Gas piping deserves a mention of its own. Some homes have flexible yellow gas tubing, known as CSST, whose makers call for a bonding conductor to protect it from lightning damage. When we find it without that bond, we point it out and add it.