Grounding questions

[detroit_fan]

I started a thread recently to ask about my antenna set up. -

http://www.satelliteguys.us/digital-over-air-ota/286844-will-antenna-wire-work-5.html

I was able to hook it up and try it out, and I'm not getting Detroit stations, but I am getting a few Toledo stations, so I am not going to replace the antenna or rotor at this time.

I plan to buy an AM21 and hook this antenna to it, but not sure how to ground it correctly.

Do I run coax from the antenna to a grounding block like this-



then run the other length of coax from the grounding block to the AM21? Then attach a piece of grounding wire from the grounding block to a grounding rod?

The antenna tower is cemented in the ground, does the tower need to be grounded additionally too? If so, can I just use a grounding clamp like this-



on the tower, with a ground wire running form the clamp to the grounding rod?

Hope this makes sense, thanks for any help.

 

[detroit_fan]

Maybe i can ask this a different way- My antenna tower is 30ft tall above ground. I don't know how deep into the ground it goes, I assume it is at least several feet, and appears to be cemented into the ground for support, since it is sturdy enough to climb up it a ways. So is that tower considered grounded? Not the coax, just the tower.

 

[Mr Tony]

I assume the tower would be grounded. I know our neighbor at the lakehouse has a 70 foot tower and I dont see any ground rod near it. Just a coax and the rotator wire

 

[detroit_fan]

I assume the tower would be grounded. I know our neighbor at the lakehouse has a 70 foot tower and I dont see any ground rod near it. Just a coax and the rotator wire

I would think so too. I'm in MI, so I would think they had to bury it deep enough that frost would not be an issue. I think our frost line is 42".

 

[Mr Tony]

same here (Minneapolis, MN)
Northern MN is 5 feet

 

[detroit_fan]

So I wonder if I can connect my coax grounding block to the antenna tower via copper wire? That way the tower is grounded, and the coax grounding block is grounded to the tower.

 

[Mr Tony]

I dont see why not

 

[detroit_fan]

Me neither. Hopefully that will work, would make my install much easier.

 

[sergei]

I assume the tower would be grounded. I know our neighbor at the lakehouse has a 70 foot tower and I dont see any ground rod near it.

When I installed my tower I installed my ground rod at the bottom of my hole which was down 6 feet and the wire is attached from it to the next section which connects to my house ground and unless you look really close you can't see it. Now if he didn't ground it then he not very smart!

 

[sergei]

Maybe i can ask this a different way- My antenna tower is 30ft tall above ground. I don't know how deep into the ground it goes, I assume it is at least several feet, and appears to be cemented into the ground for support, since it is sturdy enough to climb up it a ways. So is that tower considered grounded? Not the coax, just the tower.

It's not grounded unless you have a ground rod next to the tower and then tied back to your house ground.

 

[navychop]

When I installed my tower I installed my ground rod at the bottom of my hole which was down 6 feet and the wire is attached from it to the next section which connects to my house ground and unless you look really close you can't see it. Now if he didn't ground it then he not very smart!

It's not grounded unless you have a ground rod next to the tower and then tied back to your house ground.

You're saying a grounding rod AND a tie to the house ground? I'm not sure that's smart, nor do I think it complies with code, at least not here in northern VA.

 

[detroit_fan]

It's not grounded unless you have a ground rod next to the tower and then tied back to your house ground.

so i can't just install a ground rod without connecting that rod to my house electrical system?

 

[navychop]

so i can't just install a ground rod without connecting that rod to my house electrical system?

I believe you not only CAN, you SHOULD. But you should ask someone local who is knowledgeable. Maybe call the County.

IIRC my civilian electrical class stated bonding two separate grounding systems was a no-no. Shipboard electrical was a whole different matter.

 

[sergei]

so i can't just install a ground rod without connecting that rod to my house electrical system?

Nothing is stopping you from doing that, but you'll stand a good chance of having a ground loop which will give you all kinds of problems since by keeping the two systems separate it can create a dangerous potential between them.

 

[detroit_fan]

Nothing is stopping you from doing that, but you'll stand a good chance of having a ground loop which will give you all kinds of problems since by keeping the two systems separate it can create a dangerous potential between them.

so what if i installed a new ground rod near the antenna tower, and then ran a bare copper wire from my main panel, through the basement, through the outer wall and connected that to my new ground rod?

then connect my antenna tower to the rod using clamps and #6 copper wire. then connect my coax grounding block to that same ground rod using clamp and #12 copper wire?

 

[qwert1515]

so what if i installed a new ground rod near the antenna tower, and then ran a bare copper wire from my main panel, through the basement, through the outer wall and connected that to my new ground rod?

then connect my antenna tower to the rod using clamps and #6 copper wire. then connect my coax grounding block to that same ground rod using clamp and #12 copper wire?

That's the way you're suppose to do it.

There's a explanation and picture close to the bottom of this website under the Grounding outdoor antennas section: Antenna Basics

 

[rv1pop]

Qwerty1515 is absolutely correct according to the NEC.

We had 52 VAC between a shield of a cable that ran from The Chapel PA system and KCBI radio station. Rather shocking if I say so myself ! from experience. We ran 2 #10 ground wires as we did not have #6 available. It gave a lot of hum. so we re-floated the ground between the 2 systems and installed a 600 ohm isolation transformer. (KCBI was the campus radio station TBN's Paul Crouch started.)

 

[detroit_fan]

That's the way you're suppose to do it.

There's a explanation and picture close to the bottom of this website under the Grounding outdoor antennas section: Antenna Basics

So reading through that link I see that just installing a ground rod and connecting the mast and coax grounding block to that rod satisfies [FONT=&amp]Channel Master's grounding recommendations[/FONT], but not NEC. I'm just not crazy about a wire running through my basement that could carry a lighting strike. I've checked a few neighbors set ups and several of them have a separate ground rod installed for cable or OTA and none of those rods are connected to the main system ground at all.

In fact, on the other side of my house is a 4 foot ground rod that my cable internet is connected too, it is also in the ground without being tied to the main system ground.

 

[boba]

It's your house do as you please advice is free.

 

[sergei]

So reading through that link I see that just installing a ground rod and connecting the mast and coax grounding block to that rod satisfies [FONT=&amp]Channel Master's grounding recommendations[/FONT], but not NEC. I'm just not crazy about a wire running through my basement that could carry a lighting strike. I've checked a few neighbors set ups and several of them have a separate ground rod installed for cable or OTA and none of those rods are connected to the main system ground at all.

In fact, on the other side of my house is a 4 foot ground rod that my cable internet is connected too, it is also in the ground without being tied to the main system ground.

And that cable guy doesn't care and he had NO ideal what he's doing when it comes to grounding. The minimum most likely should have been an 8 footer rod and the only way to know for should would be to measure it. AS far as the cable in the basement that's what I do as the my tower is on the oppose side of the house and I tie into my panel box ground along with all my cables grounds and equipment. I'm guessing that all it's going to take is a lighting ground strike somewhere near you to cause damage .