Tommy Mac Discussions › Forums › Fix-it Forum: Home Improvement & Do It Yourself Repair Forum › Grounding a portable generator? › A few things. The power coming into your house is grounded › Grounding Electrodes
Billhart“Hopefully a ground rod. Grounding to a water pipe is very out of date but still exists. “
If the water supply to the building is metalic and under ground and 10 ft or longer then it MUST BE USED AS A GROUND ELECTRODE.
However it can not be the only ground electrode.
In new construction, where applicable a UFER ground electrode is required. That is a conductor that is buried in the concrete footer.
If that is not available there are several other types of electrodes that can be used. But a ground rod is most common.
But a ground rod needs to be either tested for 25 ohms or less or TWO GROUND RODS ARE REQUIRED, 6 or more feet apart.
And if the water supply pipe is not metalic, but the internal piping is metalic then the water piping needs to be bonded to the ground electrode system.