Wireless Service Providers → Re: Bonding ground to building ground

Trying to "bond" these two distant locations to prevent ground loops is not going to work as explained at the excellent MikeHolt site during discussion of single-point grounding:

you may have a very solid conductor between two points but because of the RF properties of lightning it may not be an effective bonding conductor. Thousands of volts may develop across its length during lighting activity.

»www.mikeholt.com/mojonew ··· 0427.php

No matter what, all conductors (data, PoE) of the outdoor CAT5 cable needs robust surge protection at building entry point for electrical safety inside.

Unless we are willing to sacrifice CPEs, all conductors going into it (antenna, data and PoE) need to be surge protected with proper bonding to the tower/mast grounding system.

CAT5 or RF cables should also be bonded to tower/mast body a few times at different heights to keep both at same potential during lightning surges.

lutful I don't understand how you get that those two locations should not be bonded from the link you posted. The first paragraph is very clear

A true single point ground system means just that, everything is referenced to a single point and that is were everything within your shelter is tied to the external earth ground system. The external ground system could include the utility ground, a facility ring ground, tower ground and your antenna and radial ground systems. The single point is truly a single point, typically a single bus bar or equal that is typically 4 or 6 inches by 24 inches. All system grounds terminate to this single bus bar connecting point. In reality each component and external source is effectively bonded to a single point, which is then effectively bonded to the facility or site external ground system.

All ground systems tie together at one point. That includes the tower (CPE) grounds as well as the surge protection at the building entry point for the CAT5.

LLigetfa It sounds like you are saying that you do not have a main ground at or near the main electric service entry. I have that problem with almost all of the homes I service. We are in the Texas Hill Country and it is solid limestone. Most homes just have a 6AWG or larger going underground from outdoor main cutoff panel to the electric pole where the meter is located. In that case I either bond to the ground at the electric pole or to the outside cutoff panel. I make my decision based on how the house is wired (i.e. -- where have others such as Telco bonded their equipment). I try to do the same so there is in effect a single ground point. The ground rods at the CPE location also should be bonded to this same ground point, along with your gas line, gas storage tank, water line, ductwork, gutters and basically anything conductive close to the service entrance or outside and connected to the electric system or the house.

To the contrary. I have two ground rods near the house at the service entrance bonded to the electrical panel. They are also bonded to my well casing. The wire exits the house just above grade and then goes down below grade to the sunken ground rods. The service line from the road is 300 feet (I think 4/0) all underground. There is a ground rod at the transformer on the pole at the road.

So when you said "I could have bonded it at the hydro pole but was worried about creating a ground loop" were you referring to bonding the grounds at the CPE location to one of the hydro poles nearby?

I dunno guys, Im getting confused now.
I never read anything in NEC that "DC" powered device need to be grounded. And from what I have heard on here is if you get a direct strike then NOTHING will save you, so will the home owner sue you just because it just so happen to strike YOUR antenna? Sounds kinda far fetched.

A properly designed lightning protection will prevent direct strike to radio equipment, rather the lightning will attach to an air terminal, or some other part of the protection system.
The remote dc powered radio needs surge protection and mounting structure ground for functional protection, not because of NEC.
Electricians rarely understand RF circuits. If two points are connected by a piece of wire, an average electrician will not understand the possibility of transient destructive potential difference between the two points.

If the ground at the pole failed for whatever reason, and you were connected to the grounding wire, it would create an unnecessary hazard.
Consider your cat5 as a telephone line. It needs grounded surge protection at the building entrance, and also surge protection of the remote 'CO'.