My service ground is attached to the rebar in the footers and house foundation.

quote:

Originally posted by 4MUL8R:
In nearly as short a time as SF questions are answered, the original electrical contractor explained the situation.

The ground wire in the panel, on the interior wall in the garage, is to be traced to find a location where it enters the earth. This will be in the crawl space, to start. Where this wire goes is the direction to search for the ground rods.

Somewhere outside the home walls are two ground rods, spaced six feet apart. These are bonded together. One is connected to the service panel ground.

The rods were installed and inspected before final grading, and are presently below grade.

The connection to the ground rod for the antenna is likely to be under present grade level, about six inches.

I hope the ground rods are on the meter side of the house, where I need to connect the antennas.

If you found your GEC there's no need for going into the crawl space. Just add a bonding terminal wherever the wire is accessible and run your bond from the antenna to there passing through any lighting suppression on the way. If the arrestor doesn't support #6awg, then just use another terminal on the block and run a #10 from the bonding terminal to the suppressor/arrestor.

Intersystem Bonding Terminal

Thank you Jesse for the link. I will find the GEC wire somewhere below the circuit breaker box. It is located in a drywall-finished garage interior wall, so I suspect the ground wire to the ground rods will be evident only in the crawlspace. I hope to connect to it with your linked item, then run a ground wire #6 outside to the antenna coax box which will have a copper ground plate for the three coax gas discharge terminals.

Are you trying to install actual lightning protection ?

Progress report...

In crawl space, the ground from the circuit breaker box was obvious. It comes down from the box, and is in the morass of white power cables also present. The ground wire is stapled to the floor joists. It wanders over towards the exterior wall with the power meter. From the joists, it bends downward against the cinder block foundation wall above grade, and then right at the bottom of the wall makes a 90 turn and goes through one cinder block outside.

Looks like a ground rod could be right outside the foundation wall, below grade as the electrical contractor e-mailed me.

But, the ground wire is within three inches of a foundation vent panel. Two phone communication boxes outside the home pass their ground wires past the ventilation panel and bond to the ground wire in the crawl space. Looks like that method would work for the amateur radio antenna coax as well.

I think I can delicately drill a passage through the ventilation panel to permit the antenna coax to pass through it. Then, in the crawl space, I can install a small metal panel or 2x2 metal rail on which the gas discharge tubes can be mounted, and that metal can also be bonded to the same existing ground wire. From that gas discharge tube, I can run coax about four feet over and then up through the floor OSB panel to the interior garage wall, in between studs. Then, a nice box and coverplate for coax will allow me to run the interior coax to the radio. I can also run a ground wire down that interior wall through the OSB to the ground wire, so I can ground the radio chassis.