Grounding Info & Standards: OTA/Dish/CATV/Telecom

[ota_canuck]

I noticed another recent post in another threat that was moved or removed. That post was asking about Canadian antenna grounding requirements. I'm certain that this ANSI link has been reviewed here in this thread many times in the past.

Electrical codes in North America are a muddy mess for the novice installer when it comes to antenna grounding requirements. See article #810

http://www.nfpa.org/assets/files/pdf...810-annexg.pdf

This 'ansi nfpa 70 aticle#810' as far as I know applies to Canada and US antenna grounding protocols. It is a very confusing read though. There may also be local provincial/state electrical code regulations that may vary.

In general,.. all codes require the basic requirement of grounding the antenna's mast/boom for protection during lightening strikes and grounding the coax shield for static discharge.

Though there are many other issues and questions and answers and discussions that are found within this DHC grounding thread,.. you would still have to consult your local electrical codes for specific requirements and compliances to your specific area.

______________________
In a straight and simple answer to the most common question I've seen:

Regarding using your home's cold water pipe or your electrical system ground rod:
In NO WAY should you risk compromising your home's electrical system with your antenna grounding solution.
Grounding your antenna must be regarded as a separate entity from your home's electrical system.

[ProjectSHO89]

In general,.. all codes require the basic requirement of grounding the antenna's mast/boom for protection during lightening strikes and grounding the coax shield for static discharge.

These are NOT the purpose of the Code's grounding requirements although they are recognized as side benefits of a properly grounded system.

The purpose of the Code's grounding requirement is to provide for safety in the event that the antenna mast or coaxial cable shield should become accidentally electrified.

Lightning protection of residential and commercial structures is covered by a different set of standards (NFPA 70 in the US) that provides a far more robust power handling capacity. Trying to make an antenna system perform this task is a bit of a fool's errand.

[balm]

In NO WAY should you risk compromising your home's electrical system with your antenna grounding solution.
Grounding your antenna must be regarded as a separate entity from your home's electrical system

im not sure if this related to this point, but I do NOT know of any installer (antenna) here, who ever bonds the antenna ground system to the existing house electrical ground system ! as i have said before....nor do any installers bring the house ground outside so that it can be bonded to antenna ground in the MANY cases where it is impossible or impractical to bond the two inside the house, say at the electric panel, pipes,...etc

[stampeder]

balm, does that mean they don't ground the gear at all? Or does it mean that they use a separate ground rod?

It is best to run a wire between separate grounding points to prevent any potential difference in ground states between them.

[jflarin]

Originally Posted by stampeder

Can we put a ground block anywhere on our coax lines? Theoretically yes if it is properly grounded, but in reality, no.

Theoretically, if you were to lay out two new, equal 10 meter copper wires in parallel and on one put a ground block half way through it but on the other put a ground block near the end you would have a very difficult time detecting any difference in how quickly or efficiently an electrical charge applied to the beginning of the wires would be drained off to ground.

So, putting it plainly, make sure that your home is grounded according to Code, then ground your incoming OTA/Dish/CATV/Telecom connections to it so that your home remains within Code afterwards.

Hi Stampeder,

I get your point here regarding the home ground that must stay grounded according to the code. But your example of 10 meters of copper wires makes me think that my initial message wasn't clear on my intentions.

What I want to do is to go from the chemney down 10 feet to a grounding block and then inside the house. From the grounding block, I go down with a #12 wire to an external pre-existing grounding wire (#3/0) located at about 30 feet from the grounding block. This is the grounding wire of the whole electrical system.

So technically, I haven't helped the lightning to enter the house since it will have a much lower resistance going down the external grounding wire than going through the coax inside the house, then jumping in the TV electronics, then going to the bonding wire (AWG 14) of the 120v receptable, then going down to the pannel and eventually out through that same #3/0 wire. So AFAIK, my house is safe from lightning.

Well, in fact, I don't really fear lightning. I'm in the middle of the forest on the side of a mountain. There are so many trees around the house that will draw the lightning. Of course bad luck can always happen, but what I fear the most is insurance lawyers. And the only protection against them is compliance with the Canadian Code (Nec rules discussed many times in this thread doesn't help).

By the way, Canadian Electrical Code 2012 says:
54-912 Grounding conductors
The grounding conductor shall be permitted to be run either inside or outside the building.

I wouldn't want to do that, but AFAIK, it's legal.

jf

[stampeder]

Originally Posted by jflarin

This is the grounding wire of the whole electrical system.

Yep, that is the key factor in your situation. You want to bond to that because it is your power panel's main ground point and you would be eliminating any differences in ground state between your OTA gear and the rest of your house. That means that your OTA gear would not be on a critical path of energy potential, so no unexpected electrical charges would flow through/across your OTA gear. We do what we can to reduce possible lightning damage, but it is not the core reason for grounding.

[elty]

From all I have read is:

1) If there is a direct lightening hit on your antenna then your grounding may not help much. Sophisticated lightening protection cost more money and it is not some DIY thing.
2) The NEC in the US specified how outdoor antenna needs to be grounded.
3) The Canada/Ontario code, does not specify how (or even if) outdoor antenna needs to be grounded.
4) The main purpose of the grounding is to remove static charge build up. Without any static charge the antenna will not be more attractive to lightening (doesn't mean lightening won't hit it).
5) But if you don't ground the antenna properly, if something ever going to happen your insurance most likely will find this as an excuse not to pay.
6) If antenna is neutral (no static charge), then the chance that it will be hit by lightening is the same as another area of the same height.

Am I correct here? Also the mast and coax needs to be grounded separably, why is that? If the antenna is connected to the mask, then shouldn't one cable connect to ground be sufficient? Is it because of a "what if" scenario where the antenna is blown off by wind (or something) and the mast just stand on the roof without proper grounding?

[jflarin]

Originally Posted by elty

From all I have read is:

3) The Canada/Ontario code, does not specify how (or even if) outdoor antenna needs to be grounded.
6) If antenna is neutral (no static charge), then the chance that it will be hit by lightening is the same as another area of the same height.

Am I correct here?

3) That is false. Here is part of Canadian Electrical Code (C22.1-12)

54-008 Receiving equipment and amateur transmitting equipment Rules
Rules 54-800 to 54-1006 apply to
(a) radio and television receiving equipment; and
(b) amateur radio transmitting equipment.

Then: (only item 1):

54-800 Lightning arresters for receiving stations
(1) A lightning arrester shall be provided for each lead-in conductor from an outdoor antenna to a receiving
station, except where such a lead-in conductor is protected by a continuous grounded metal shield
between the antenna and the point of entrance to the building.

54-900 to 54-922 give more details on how to ground, often refering to section 10 of the same code.

Regarding 6), I can't support my argument with documentation, but as far as I remember from college/university, the lightning will take the path with least resistance. Although an object higher will offer less resistance between the clouds and the ground, this affirmation is based on the fact that air is something constant and will ionize at a specific volt/M electrical field intensity. real air isn't constant (moisture content, air temperature, density, effect of wind) will all affect where the lightning will strike. Anothing thing I remember, is that electrical field is the most dense around pointy things (it is related to the radius of conductive object, a pointy thing having a very small radius, hence drawing the lightning onto the lightning protection on a top of a building.)

Originally Posted by elty

Also the mast and coax needs to be grounded separably, why is that?

You have to ground the mast because rule 54-922:

54-922 Grounding of antennas
Masts, metal support structures, and antenna frames for receiving stations shall be grounded in accordance with
Section 10.

You have to ground the shield of the coax because you don`t buy a lightning arrestor as decribed in 54-800.

Originally Posted by elty

If the antenna is connected to the mask, then shouldn't one cable connect to ground be sufficient? Is it because of a "what if" scenario where the antenna is blown off by wind (or something) and the mast just stand on the roof without proper grounding?

If both the cable (center conductor, outer shield) and the structure of the antenna are all tied together, then you wouldn't have any signal coming in the cable. If you take a Yagi type antenna, you have a main boom, connected to a bunch of director and one reflector (the last largest element) Those get connected to the mast and are thus protected by the mast grounding. But between the directors and the reflector, there is one active element that is connected to the coax cable and it must be isolated from the boom (and thus the mast). That active element is grounded through the grounding block just before the cable enters the building.

jf

[ljayszabo]

I've just finished the setup of two antennas mounted on opposite sides of a brick chimney via two separate j-poles. I've installed a grounding-block near the base of the chimney for the RG6 cable and attached it to a newly installed 10ft grounding rod.

I was hoping that someone can help so that my setup is in compliance with Canadian code. Reading through this thread, I have discovered that I need a separate ground wire for my antenna j-poles (is this the case even if they are mounted on brick?).

1. If an additional ground is required for the j-poles, can I connect the two masts via grounding wire (horizontally) and then down to the grounding rod?

2. Can the ground wire from the masts come down the side of the chimney, through the grounding-block and then to the grounding-pole...or is it better to have a separate ground wire for the masts?

3. I have aluminum siding and eves, any issue with the ground wire being too close to or touching these? Does unshielded vs shielded ground wire make a difference here?

4. Can the masts be grounded to the same grounding pole as the grounding-block that that the RG6 is attached to? I thought I read that this could cause issues with reception?

5. What is the best way to attach the newly installed grounding rod to the house's ground? I read this should be done to minimize the difference in charge between the two grounding systems. Can I ran a grounding wire underground to attach the new grounding rod to my copper water pipe which is about 6ft away from the grounding rod? Shielded or unshielded ground wire here?

Thanks for the great info on this forum...it has saved me a lot of time and headache thus far.

Cheers,

[roger1818]

Originally Posted by ljayszabo

I have discovered that I need a separate ground wire for my antenna j-poles (is this the case even if they are mounted on brick?).

yes

1. If an additional ground is required for the j-poles, can I connect the two masts via grounding wire (horizontally) and then down to the grounding rod?

You could do that, but it would be best not to have a horizontal stretch of wire. Would probably be better to splice two wires together below both masts so that the wires are always somewhat vertical.

2. Can the ground wire from the masts come down the side of the chimney, through the grounding-block and then to the grounding-pole...or is it better to have a separate ground wire for the masts?

Some say you can do this, but I argue that it is better for the antenna ground to go to the rod directly. It could loop back to the grounding block though but the gauge of wire needed for the mast is overkill for the grounding block.

3. I have aluminum siding and eves, any issue with the ground wire being too close to or touching these? Does unshielded vs shielded ground wire make a difference here?

Good question. Not 100% sure, but with large voltages, a small amount of insulation or a small spark gap is likely going to be irrelevant so my guess is it doesn't matter.

4. Can the masts be grounded to the same grounding pole as the grounding-block that that the RG6 is attached to? I thought I read that this could cause issues with reception?

Yes. They should use the same grounding rod. You may be confusing the use of an electrical ground, though even then the two grounding rods should be bonded together to avoid a ground loop.

5. What is the best way to attach the newly installed grounding rod to the house's ground?

Vague question.

I read this should be done to minimize the difference in charge between the two grounding systems.

Yes

Can I ran a grounding wire underground to attach the new grounding rod to my copper water pipe which is about 6ft away from the grounding rod?

Not sure but I don't think connections can be underground.

[ljayszabo]

Excellent, thanks for the swift reply roger1818...it's much appreciated!

Although I'm quickly becoming an OTA enthusiest, safety (or minimizing damage in a worst case scenario) is still priority. My main electrical feed comes into the house underground a few feet from my chimney (where the antennas are mounted). I could not locate the original grounding rod for the house (if any) and it looks as if most of our internal wiring uses the coper water pipe as ground.

The last thing I need to understand is how to connect the grounding rod that I installed for my OTA gear to the house's main ground. Seems like my best option is to run a ground wire outside from the OTA grounding rod to the copper water pipe a few feet away. Can I not run a shielded ground wire underground between the two (leaving the connections above ground)?

Thanks again!

[jflarin]

Originally Posted by ljayszabo

I have discovered that I need a separate ground wire for my antenna j-poles (is this the case even if they are mounted on brick?).

I read:

54-922 Grounding of antennas
Masts, metal support structures, and antenna frames for receiving stations shall be grounded in accordance with
Section 10.

I can't quote the whole section 10 here, but I don't see anything regarding the fact that equipment is isolated from electrical circuit. I see:

10-002 Object
(1) The object of bonding metal parts and metal systems together and to the grounded system conductor is
to reduce the danger of electric shock or property damage by providing a low impedance path for fault
current back to the source and to establish an equipotential plane such that the possibility of a potential
difference between metal parts is minimized.
(2) The object of grounding the electrical system and non-current-carrying metal parts is to connect the earth
to the equipotential plane, thereby minimizing any potential difference to earth.

point 1 does not apply because there is no electrical supply in the antenna mast. But point 2 can't be obviously rejected.

Originally Posted by ljayszabo

1. If an additional ground is required for the j-poles, can I connect the two masts via grounding wire (horizontally) and then down to the grounding rod?

54-908 Grounding conductor to be run in a straight line
The grounding conductor shall be run in as straight a line as is practicable from the lightning arresters or antenna
mast, or both, to the grounding electrode.

Going between the 2 Jpoles horizontally and then going down doesn't look like straight line as possible, but this rules looks soft to me : is it practical to go horizontal? Maybe going diagonal down up to a tying point? I can't say.

What I am going to try to do is to use the same wire, going from the mast, through the grounding block (without cutting the wire) then down to the grounding electrode. That way the ground is continuous without splice or joints and I still use a single wire.

Originally Posted by ljayszabo

2. Can the ground wire from the masts come down the side of the chimney, through the grounding-block and then to the grounding-pole...or is it better to have a separate ground wire for the masts?

The schematics I have seen in Bell Expressvue manual show 2 independant wires. Still the grounding block in my hand have 2 ground wire connection, which implies having a ground wire go through the block.

I also read:10-806 Installation of system grounding conductors (see Appendix B)
(1) The grounding conductor for a system shall be without joint or splice throughout its length, except in
the case of busbars, thermit-welded joints, compression connectors applied with a compression tool
compatible with the particular connector, or where it is necessary to control the effects of stray earth
current, devices specifically approved for connection in series with the grounding conductor.

So cutting the grounding wire from the mast to the rod at the terminal block, is it a joint? Or is it a connection? I can't say.

Originally Posted by ljayszabo

3. I have aluminum siding and eves, any issue with the ground wire being too close to or touching these? Does unshielded vs shielded ground wire make a difference here?

What do you mean by shielded? Insulated?

Originally Posted by ljayszabo

4. Can the masts be grounded to the same grounding pole as the grounding-block that that the RG6 is attached to? I thought I read that this could cause issues with reception?

That's what I see in Bell Expressvue Manual (and other sources). I don't remember seing anything banning it in section 54 of the code.

Originally Posted by ljayszabo

5. What is the best way to attach the newly installed grounding rod to the house's ground? I read this should be done to minimize the difference in charge between the two grounding systems. Can I ran a grounding wire underground to attach the new grounding rod to my copper water pipe which is about 6ft away from the grounding rod? Shielded or unshielded ground wire here?

Best way?

10-902 Grounding conductor connection to water pipe electrodes
(1) Where the grounding electrode is a metal water-piping system to which a common grounding conductor
or the grounding conductor of a system is attached, the point of attachment shall be
(a) on the street side of the water meter; or
(b) on a cold-water pipe of adequate ampacity and as near as practicable to the point of entrance of the
water service in the building.
(2) Where practicable, the point of attachment shall be accessible.
(3) The metal cold-water system shall be made electrically continuous from the point of attachment of the
grounding conductor to the water service entrance by bonding together all parts that contain insulating
sections or that may become disconnected at such locations as meters, valves, and unions.

54-902 Insulation of grounding conductor
The grounding conductor shall be permitted to be uninsulated.
54-906 Mechanical protection of grounding conductor
The grounding conductor shall be protected where exposed to mechanical injury.

but

10-806 Installation of system grounding conductors (see Appendix B)
(2) A No. 6 AWG or larger copper grounding conductor that is free from exposure to mechanical injury shall
be permitted to be run along the surface of the building construction without metal covering or protection, if it is rigidly stapled to the construction; otherwise, it shall be in conduit, electrical metallic tubing, or cable
armour.
(3) A No. 8 AWG or smaller grounding conductor shall be in conduit, electrical metallic tubing, or cable
armour.

and

10-702 Spacing and interconnection of grounding electrodes
Where multiple grounding electrodes exist at a building, including those used for signal circuits, radio, lightning
protection, communication, community antenna distribution systems or any other purpose, they shall be
(a) separated by at least 2 m from each other;
(b) bonded together with not less than a No. 6 AWG copper conductor protected by location from mechanical
injury;

So I see that you need AWG 6 and it doesn't need insulation but it needs protection from mechanical injury. If it is in the ground, I think it is protected (and putting a GROUNDING wire in the GROUND cannot be a problem!)

However I see above that you grounding rod is 6 feet from the water pipe. To me, 6 feet is less than 2m? Unless the pipe enters the soil at more than 2m from you antenna ground?

jf

[roger1818]

Originally Posted by jflarin

So I see that you need AWG 6 and it doesn't need insulation but it needs protection from mechanical injury. If it is in the ground, I think it is protected (and putting a GROUNDING wire in the GROUND cannot be a problem!)

You would have to read the section on cable burial. I seem to remember someone telling me that buried cables must be surrounded by a foot of sand to protect them from injury, but don't quote me on that.

[ljayszabo]

Wow, thanks for the detailed references jflarin!

I've decided to run a separate AWG3 wire (uninsulated) for the antenna masts and keep the grounding block on a separate run. So, a continuous straight vertical from one antenna down to the grounding pole...and one down on a diagonal from the other antenna joined via a grounding coupling (so it looks like a y).

Then, bury an AWG3 wire (insulated) from the grounding pole to the water pipe. The caveat here is that the water pipe does not enter the ground here...it's just a tap for outside. The water service actually enters the house from the basement floor (well below grade) on the opposite side of the house. My only other option would be to run the ground wire through the house and attach it to where the water service enters. However, this seems like the same thing as attaching it to the copper water pipe that runs through the house...and the and the section reads flexible to include "where practical", etc.

I believe this is the best that I can accomplish under the circumstances and at lease have done my due-diligence to mitigate any potential damage (I hope).

Thank you roger1818 & jflarin for your time and expertise.

[roger1818]

Originally Posted by ljayszabo

Then, bury an AWG3 wire (insulated) from the grounding pole to the water pipe. The caveat here is that the water pipe does not enter the ground here...it's just a tap for outside.

AWG6 is fine for this. Also, make sure you have a jumper around your water meter. They are made of bronze thus aren't very good conductors. Also make sure you only have copper pipes inside your house between the tap and your electrical grounding point (likely near the water service entrance). Other than that it is should work well (it is actually a good solution IMHO).