Electrical – How to ground residential network equipment

cablingelectricalgroundinggrounding-and-bonding

I needed to run some Cat5e UTP network cables and decided to add network outlets to most rooms, run new phone wiring and RG6 as well.

Much of what I've seen and read about residential and small office installations doesn't mention grounding much but I know that in the data center It's an important consideration. I called a local antenna installer (the only one I could find) to have them move an attic antenna to the roof and they said they don't recommend grounding the antenna. I'm a bit confused by both the lack of information and conflicting information. The bits I've seen on the TIA residential spec didn't mention grounding.

All the cables will be terninated on a plywood panel in the basement with 2 small wall mount racks. One for patch panels (coax and cat5e) another to hold a network switch. Cabling is cat5e UTP for data and phone. Coax is RG6 with 2 seperate runs, one for commercial tv provider, other for an attic mounted antenna that I'd like to eventually move to the roof.

Is there a requirement (USA NEC) to bond these racks, and the equipment in the racks?

If it's not a requirement are there good reasons to bond this equipment?

How would you recommend grounding bonding this setup? The current drops from providers are properly grounded.

In larger data centers I've seen those big copper grounding bus bars which seems like overkill. In smaller installations I've seen small aluminum(?) grounding bars that look like the ones in electrical panels. From there ground wires connect between the block/bar to the racks and then the racks are connected to patch panels and other equipment with ground wire and grounding lugs.

Where can the other end of the grounding conductor go? People have different opinions of what the code states. Some have said a separate ground rod, other's have tied it to all sorts of things including steel building structure, water pipes, electrical conduit….

This is what's available to me where I'm mounting my equipment.

A) Lots of copper cold water pipe on the house side of the water meter. Main line is underground copper that runs at least 10' in ground. This would be the easiest/cheapest. I know in the past the cold water line (house side) was at least once used to ground the incoming phone service.

B) Some armored cable (old 2 conductor where armor is grounded)

C) The street side of the water meter is a bit further away and a little difficult to get to but possible if necessary and less than 20' of cable run to it. Thre's a ground wire on the street side of the meter for the electric panel but I think there's also another ground wire going outside from the panel.

D) Main electrical panel. The wire run would be greater than 20' though.

The above is just to illustrate what I "know" (think?) and what I have available.

Best Answer

This is a bigger can of worms than meets the eye. There are huge arguments over all this.

This is a coax grounding block:

coax grounding block

This is a grounding bar:

grounding bar

This is a grounding bridge, your cable company or telephone company probably has one on the outside of the house at the electrical service entrance:

grounding bridge

What I'd do:

  • Run a ground cable from your frame to the grounding bridge. Use the biggest cable that will fit properly in the bridge. Don't use A-D above.
  • Install a grounding bar that will handle that wire, at your frame in the basement.
  • Run a ground wire from your metal patch panel rack to the grounding bar, use grounding lugs on the rack. Probably not necessary, but use Noalox between the lug and the rack. Remove paint if you want to go all in.
  • Install and ground coax grounding blocks for your antenna and CATV service.
  • Use good quality surge strips, at the frame and through the house, and check your outlets with a receptacle tester to make sure they have ground wires - surge strips generally don't work without a good ground.
  • If any of your equipment has a grounding lug on the back, ground it. (For example, many of the Netgear metal cased switches have a ground lug on them.) AFAIK only necessary on equipment with a two wire power plug.
  • Remember, holy wars over all this - some will say this is all totally wrong. This is what I would do though after following all the arguments.

Edit:

There is a good chance your patch panel doesn't ground the coax that goes through the house. However if you use surge strips that have a coax port in those places, and the coax has been terminated properly so the body of the plugs are bonded well to the shiled, and the outlets those surge strips plug into have a good ground, you should be fine.

One last thing - this whole thing hinges on good grounding of your electrical system. If you want to be really careful there, have an electrician check the grounding and bonding and if possible ground resistance. This is IMO worth doing in general.