tonsoffun said:
Hi everybody,
Just a few comments on bonding everything to your main ac ground. I wanted more input on grounding my tilt over and coax surge protectors after my install.
I talk to 2 of my hydro inspectors and they both told me that if my ground wire and ground rod is MORE then 2 meters away from the house panel ground, they said to leave everything seperatly grounded outside and to not bond to the ac ground.
They do not want a cable with that much voltage to be entering the house, specially having to travel at least 30 feet inside the house to my panel which is on the other side of the house.
Again, all the laws and rules are different in Canada too the US but all have the same basics rules I guess.
Take care
tonsoffun,
The electrical codes are similar between U.S. and Canada. In the U.S., new construction of such a facility would require bonding conductors to be less than 20' from the remote ground rod to the AC Service entrance grounding electrode. There are ways around this, not intended to ignore the codes but to supplemnt their intent with safe practices.
Many if not most of us create a radio equiment room that is 30, 50, or 70' from the AC entrance. This is a problem, but not insurmountable. Ignoring the code and leaving a remote ground is possibly the worst advice. Your utility company's pole is statistically the most likely source of lighning energy insult to your home, not the antenna on your roof.
Even so, the rooftop mast is capable of being attached by either a branch-leader from a nearby strike or directly attached on its own. The number of trees and their height and distance around your home is what will determine if the home can suffer a direct attachment. Bonding the remote ground rods from Dish networks and rooftop or yard/tree-supported antennas remains a critical part of every lightning protection design.
However I would not recomend you route such bonding through your home either, as the best place for such bonding conductors is buried outside along the perimeter of the home. Supplemental ground rods along the way can help maintain a high current-carrying capacity of this bond. This greatly reduces the inductance of a long bonding connector which would otherwise have astronomical voltage differnces to lighting even if it was near zero ohms DC resistance. So yes you should definitely bond all remote grounding rods to the AC service entrqnce rod. You could also improve the grounding system at that panel entrance, as it probably has only one rod, or possibly two and combined they may have a very high resistance even at DC if your soil is sandy or dry most of the year. It is THAT poor grounding point which allows electric meters to be blown 100' from the house in a blazing fireworks display when the nearest power pole gets struck. AC surge protectors inside the meter or inside your main AC panel can handle the 10ka insult from power poles but the shack power needs its own 10ka minimum surge protection from EMI that will envelop house wiring at various points inside the home if struck directly.
By the way, I have watched these posts and am very happy that the level of knowledge of lighting protection has improved greatly here on this board. I hope I had a small part in that encouragement to learn more about the process from my website which was referenced early in the posts. For those who use it, I will be updating information from the NFPA 2004 edition of 780 Lightning protection to the new 2008 edition.
Brgds,
Jack
Virginia Beach
