[scottchez]

% Ground Loops and 27' run to bound to main ground

I know there are others threads, I read them all. I am still confused.

My dish is on the opposite side of the house from the electrical ground due to line of sight issues. This dish is on the 1st story level roof on the side but not on the 2nd story roof.

It is grounded on that side of the house to a 8' ground rod that is NOT BOUNDED to the other side of the house main ground. I know now this against code, but the electrician that put the rod in did not do anything to bound it (I watched him do it).

I was reading on some other sites that not having it Bounded to the main will cause MORE if a risk form lightening. I ask because a month ago Lightening hit down the street and I took some surge damage, mainly through the Catv Telephone line and internet but it also took out the garage door opener and my DIsh Multi Switch.

What should I do?

Option One- Leave it as is (ground on other side to an 8' ground rod and Not bounded to the rest of the house

Option Two- or buy a very long wire and bound it to the main electrical ground? We are talking a 27' run.

Option Three- un ground the dish as ground loops cause more issues as in my Surge issue from last month?

 

[Tiger62]

Bond the 8' ground rod to the electrical service ground with #6 copper wire. 27' run is no problem. #6 copper is about $0.80 per foot.

 

[BattleZone]

Having two different grounding points means that there is a possibility of two different voltages at the grounding points. This will cause electricity to flow through the equipment from one point to the other, known as a ground loop, and can cause all kinds of problems.

The second ground rod definitely needs to be back-bonded to the main house ground. As Tiger stated, you need to use 6 gauge bare copper wire for this, per NEC code.

 

[flipptyfloppity]

I believe that is true, if it is grounded but not bonded, ground loops can cause ground current flow which can cause damage.

Option 2 isn't great, because I think the bonding wire has to be under 20' long anyway.

In reality, what you have is just fine, it us very unlikely to cause any problems (including damage from ground loops).

It is likely there is nothing you could have done to prevent damage in your house from a nearby lightning strike. Including surge protectors, lightning rods and bonded stakes.

 

[sungam]

Option 2 isn't great, because I think the bonding wire has to be under 20' long anyway.

The NEC imposes no limits on the length of the bonding conductor. Anytime a separate ground rod is used it should be bonded back to the building ground. The only requirement is that it be #6 or larger copper and that it be protected from mechanical damage.

 

[scottchez]

What about a 4th option?

From the DIsh to the Main electrical ground it would be about 32' since the dish is on the 1st floor roof.

Is that option any better? What size wire would I use if that option is good?

 

[joe diamond]

Sometimes it is easier to just rub the cable with ground back to the main bond.The coax with ground can be run through a crawl or around the perimeter of the inside of an unoccupied basement to a ground block within ten feet of the bond if it is easy to do.



We once moved our E meter and the inspector failed the work because the electrician back bonded with something smaller than #6 and flunked it again because the helper who did the work made tight right angle bends in the #6 on the second attempt.

Joe

 

[erict]

Having two different grounding points means that there is a possibility of two different voltages at the grounding points. This will cause electricity to flow through the equipment from one point to the other, known as a ground loop, and can cause all kinds of problems.

The second ground rod definitely needs to be back-bonded to the main house ground. As Tiger stated, you need to use 6 gauge bare copper wire for this, per NEC code.

It can be bare or insulated per NEC.

 

[Tiger62]

Option 2 isn't great, because I think the bonding wire has to be under 20' long anyway.

In reality, what you have is just fine, it us very unlikely to cause any problems (including damage from ground loops).

It is likely there is nothing you could have done to prevent damage in your house from a nearby lightning strike. Including surge protectors, lightning rods and bonded stakes.

No offense, but you really shouldn't be giving advice on a subject if all of the advice is predicated on I think, it is very unlikely, or it is likely that... You are just voicing an opinion based on who knows what. The first two of your opinions are wrong, and the last one should have stated "It is possible", rather than "It is likely" BTW.

 

[kd7eai]

No offense, but you really shouldn't be giving advice on a subject if all of the advice is predicated on I think, it is very unlikely, or it is likely that... You are just voicing an opinion based on who knows what. The first two of your opinions are wrong, and the last one should have stated "It is possible", rather than "It is likely" BTW.

Amen to that! Anything that pertains to life safety issues should not be left to opinions. To my way of thinking, as a building inspector, it is absolutely critical that issues such as grounding and bonding should not be left to conjecture but rather to the NEC. Thats what it's there for. If you ever have doubts like that again, please call your local building department or go check out the NEC at the library.

 

[flipptyfloppity]

Amen to that! Anything that pertains to life safety issues should not be left to opinions. To my way of thinking, as a building inspector, it is absolutely critical that issues such as grounding and bonding should not be left to conjecture but rather to the NEC. Thats what it's there for. If you ever have doubts like that again, please call your local building department or go check out the NEC at the library.

The NEC is just someone else's conjecture anyway.

Want the real truth? There's no such thing as a single ground. You want to use a #6 wire to bond grounds? Fine, go ahead, but that wire itself has a resistance (R), and if there is a current (I) flow across it, that means one of the grounds is I*R volts above the other anyway (assuming the actual earth is at different potential, which is why the bonding wire is there in the first place).

There's no absolute ground period. The NEC is just a guideline (albeit a good one). Additionally, people quote the NEC as if it were designed for satellite installs when the two sections quoted are for aerial masts (relatively tall OTA antennas) and cable TV, both of which have significantly different issues than satellite antennas.

Unless you have access to superconductors (that don't break down at high currents), you are just approximating earth ground anyway, no matter how many bonding wires you have and how few or many grounding stakes you put in.

What's really key is you make sure no significant potential can be present on the cases of the devices you are using. That's good for safety. Second would be to try to keep there from being significant current flow along the braid of your coaxes, that helps keep from having to replace your devices due to damage. If you do the top two and you aren't having hum problems, then you're in good shape.

 

[kd7eai]

The NEC is just someone else's conjecture anyway.

Well not exactly. It is a consensus code with contributions from both public and private sectors.

<<<The NEC is just a guideline (albeit a good one).>>>

Again this is not correct. Where it is adopted, it is the law. It is not a guideline.

<<<Additionally, people quote the NEC as if it were designed for satellite installs when the two sections quoted are for aerial masts (relatively tall OTA antennas) and cable TV, both of which have significantly different issues than satellite antennas.>>>

See article 810. It is about radio and television equipment.

So in conclusion, the communications ground rod, in fact, must be bonded to the electrical service ground system, in order to comply with the law(that is, of course, if the NEC is adopted as law in that particular jurisdiction.)

If there is no building department in your area, then by all means, you can doing whatever the hell you want to do.

 

[Tiger62]

To the original poster, Scottchez...

You have the advice of a registered electrical engineer, the advice of a building inspector, and the advice of a poster called flippityfloppity.

You make the call and good luck.

 

[scottchez]

Thank you everyone for the advice.

 

[joe diamond]

One of the shortest grounding threads I remember.

Joe

 

[erict]

One of the shortest grounding threads I remember.

Joe

AMEN