My new cable TV coax will enter my house at the far corner relative the location of all my other utilities (main electrical panel, water, gas, telephone, and a wire to an existing buried ground plate) and the internet modem/router, which is its destination. I have pre-installed coax running from one location to the other so it'll be a simple matter to get the cable signal to the networking equipment, but the question is: where to ground it?

Normal advice is to install a coax grounding block as close as possible to where the coax enters the house. At that location, I have no copper plumbing. I do have a secondary breaker panel, which is of course grounded back to the main panel. Neutral and ground are, per code, not bonded at that panel; they are bonded only at the main panel. Also at that location I have an iron gas pipe, which I believe is off limits.

So if I install a coax ground block where the coax enters the house, can I run a ground wire into the nearby electrical panel, and connect it to the ground bar? It feels wrong to run a signal ground wire into a breaker panel, but of course, it's a good ground and it's a convenient location.

If I "defer" the ground to the natural terminus of the coax, where the other utilities are, I can very conveniently ground it to plumbing and the buried plate. That'd be about 50' of cable run from where it enters the house.

Or do I need to install the ground block at the entrance location, and separately run a ground wire back to the main utility location? This would be least convenient.

As a tag-on question, from the cable box on the side of the house (if it was telco I'd call it the "demarc") there is a ground wire that's now not connected to anything. Should it be connected to a stake at that location? or brought into the house and tied into the interior coax ground?

  • Around here the cable company will do this. They'll do it outside and if there's nothing there as in your case they'll drive a stake. And then after entering the house I would have them run straight to my modem without adding any connectors of my own on the way. They provide ground and they provide the only connector between the pole and the modem, which is outdoors to serve the ground block. Unless you have TVs then there's an extra splitter before the modem but make sure they use a two-way splitter there and then more splitters after that if you need them.
    – jay613
    Jul 1, 2021 at 20:23


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