Ground block inside, ok??

[ksat1]

Just had dish installed last week. I had done some research on grounding, and was expecting the ground block be placed outside near the feed through point, but installer suggested putting it inside, to avoid moisture problems. That sounded logical to me, so we mounted it on the basement ceiling (1st floor joist), within a couple feet of wall feed through. Location is about perfect, as the copper water line comes through the basement wall directly below that point, clamped ground to that, so only about 7' of ground wire.

Just wanted to get a second (or more) opinion on mounting the ground block to a wood joist inside the house. Any issues, safety or otherwise, to be concerned with?

His work was very neatly done (which I made sure of), so my impression anyway was that he knew right from wrong.

Thanks.

 

[Mike500]

Codes require outside mounting.


That's what they make weatherproof boxes for.

 

[dodge]

Nec States ground block be mounted outside near the cablepoint of entry into the building, I have done quite a few installs where I put the ground block inside the basement just as yours and never had a problem. I have seen ground blocks corrode out even in a weatherproof box, due to high humidity.

 

[iwannarock1]

In Minnesota,(where the electrical inspector does follow us around, and fines contractors for not properly grounding), it is ok to put it inside.
One less connection that you have to worry about moisture and corrosion.You should have tipped the guy an extra $20 for putting it inside

 

[KE4EST]

I agree it is fine inside.

 

[Claude Greiner]

Somewhere it says outside, but either location should be fine.

Afterall if your house got hit by lightning, it would not make much of a difference if the ground block was outside or inside!

 

[Mike500]

The main reason they should be outside is because ALL codes recognize that any high amperage flow of current from a lightning strike would readly cause a fire inside the structure.

Combustible material has been know to smolder for days inside of wooden structures.

The cable companies, as well as the telephone companies, use weatherproof boxes for the reason that they provide longevity for their installed base. They don't install them, because they are not needed. Since they have to maintain their own connections, they KNOW that the investment is worthwhile.

Satellite companies need only to guarantee thier installs for 90 day to one year. They prefer to SELL warranty plans. Any install that fails means an opportunity for a SALE of an extended warranty or an opportunity to extend the commitment contract. It is basically a GOOD marketing tool for them.

 

[vegassatellite]

Let's just put it this way: If a catastrophic amount of current made its way on to your cables, would you want that current entering your home before it crosses to the ground connection?

Imagine a home with overhead power lines and a tree limb fell on the power line to the home, causing the power lines to hit the dish on the way down. For a brief moment, all the power the power company makes available to its customers through their transformer suddenly energizes your coax.

The coax is probably going to get vaporized as well as the #10 ground wire. The ground block may well get flash melted, throwing hot metal slag everywhere. The lower resistance of a ground path means the bulk of the current will flow that way. Personally, I would rather that path be outside the home.

 

[Mike500]

Let's just put it this way: The coax is probably going to get vaporized as well as the #10 ground wire. The ground block may well get flash melted, throwing hot metal slag everywhere. The lower resistance of a ground path means the bulk of the current will flow that way. Personally, I would rather that path be outside the home.

I'll totally agree. That's why the codes are written as they are. The path of least resistance mut be "outside" and to ground. I've seen so many non-complying and "grandfathered" existing conditions. It would be a remote possibility that they WILL cause a fire. But, like "Adrian Monk", I an obsessive and compulsive when it comes to safety. You cannot be too safe.

 

[Andrewwski]

They put it inside quite often here. Not just the satellite companies though - the cable and telephone companies do too.

I have no problem having it inside as long as it's near the point of entrance.

 

[bhelms]

I too mounted my GBs inside for weather protection, very close to the point of entrance. In the case of my TV antenna, there is a ground rod located outside near the antenna base. The ant. system ground wire (#6 solid copper) comes all the way down from the rotating part of the antenna through the screw on that rod, into the house, through the GB, then on to the main entrance panel ground in a single, unbroken piece. There is a separate, co-located GB for the 3 leads that come from my sat. dishes and there is a short copper wire from that GB to the one for the antenna. The dishes themselves have a #10 stranded THHN connection coming from the dish mounts into their GB then also on to the main panel. The bonded connections to the panel are more important to the grounding and system performance than the ground rod, but my thought was that if I do indeed get a direct hit, then that rod might bleed off a good part of the strike to that nearest grounding point. But as Claude mentioned, no grounding scheme is likely to protect you completely in the case of a direct hit! The real value is in protecting your house and equipment from static build-up and the EMP from a nearby strike, both of which are much more likely. And your insurance co. would want to know that the system is grounded if you have a claim. I don't think (but really don't know for sure) whether or not the GBs being inside vs. outside would be an issue, but I'm quite sure having NO ground would be...!

 

[Bradtothebone]

Nec States ground block be mounted outside near the cablepoint of entry into the building, I have done quite a few installs where I put the ground block inside the basement just as yours and never had a problem. I have seen ground blocks corrode out even in a weatherproof box, due to high humidity.

Not to be argumentative, but here is a quote from Section 820 of the 2005 NEC, which deals with CATV systems (there is no specific section on satellite receiving equipment, AFAIK):

"820.93 Grounding of Outer Conductive Shield of a Coaxial Cable.
The outer conductive shield of the coaxial cable shall be grounded at the building premises as close to the point of cable entrance or attachment as practicable.
For purposes of this section, grounding located at mobile home service equipment located in sight from, and not more than 9.0 m (30 ft) from, the exterior wall of the mobile home it serves, or at a mobile home disconnecting means grounded in accordance with 250.32 and located in sight from and not more than 9.0 m (30 ft) from the exterior wall of the mobile home it serves, shall be considered to meet the requirements of this section.
FPN: Selecting a grounding location to achieve the shortest practicable grounding conductor helps limit potential differences between CATV and other metallic systems."

I don't read anything there that indicates the GB needs to be outside. Is it better to be outside? Probably. Is mine outside? No.

Brad

 

[bhelms]

Yeah - I always interpreted that "...as close to the point of cable entrance or attachment as practicable" part as meaning either side of the wall. Electrically "sound" ?? Depends on many other factors, like whether or not the actual/primary attachment to ground is inside or out (per my post above) and, more importantly, the impedance of that path. "Legal", as in will insurance cover a loss? TBD, and YMMV...!

(NOTE: Impedance is not determined by just the DC resistance of the conductor, but its shape and how it's routed!)

 

[charlesrshell]

Not to be argumentative, but here is a quote from Section 820 of the 2005 NEC, which deals with CATV systems (there is no specific section on satellite receiving equipment, AFAIK):

"820.93 Grounding of Outer Conductive Shield of a Coaxial Cable.
The outer conductive shield of the coaxial cable shall be grounded at the building premises as close to the point of cable entrance or attachment as practicable.
For purposes of this section, grounding located at mobile home service equipment located in sight from, and not more than 9.0 m (30 ft) from, the exterior wall of the mobile home it serves, or at a mobile home disconnecting means grounded in accordance with 250.32 and located in sight from and not more than 9.0 m (30 ft) from the exterior wall of the mobile home it serves, shall be considered to meet the requirements of this section.
FPN: Selecting a grounding location to achieve the shortest practicable grounding conductor helps limit potential differences between CATV and other metallic systems."

I don't read anything there that indicates the GB needs to be outside. Is it better to be outside? Probably. Is mine outside? No.

Brad

That is how I read the code too so I went with an inside job.

 

[vegassatellite]

I would rather replace a corroded connector than have a 400 amp load crossing to ground inside my home.

 

[charlesrshell]

I would rather replace a corroded connector than have a 400 amp load crossing to ground inside my home.

I don't think anything would work for that vegassatellite. My main concern is draining off the static and no ground loop problems.

 

[ksat1]

I appreciate everyone's input, from both sides, pros & cons to either option I guess. Reading through this has actually given me a new idea, which may not do anymore than to ease my mind regarding the possible fire hazard, but even if that's really all it does, it will be worth the effort.

I like having the GB inside, protected from the elements, to minimize corrosion issues. My closest, and most logical, ground point is also inside, as I noted in my initial thread. So, if the GB were outside, the path to ground would still pass through the wall to get to the interior water line.

Given that, my thought is to keep it all inside, but maybe isolate it somewhat. I have excess cable, so think I'll mount an electrical junction box of some sort part way down on the concrete basement wall. The GB can then be removed from the floor joist above and mounted inside of that box, behind a cover, completely enclosed. I would then only have about a 3' vertical run of ground wire down to the water line.

Any thoughts on that idea?

Also just want to say this forum is the most useful site I've ever stumbled across on the web, THANKS!:up

 

[Liquidforce88]

I appreciate everyone's input, from both sides, pros & cons to either option I guess. Reading through this has actually given me a new idea, which may not do anymore than to ease my mind regarding the possible fire hazard, but even if that's really all it does, it will be worth the effort.

I like having the GB inside, protected from the elements, to minimize corrosion issues. My closest, and most logical, ground point is also inside, as I noted in my initial thread. So, if the GB were outside, the path to ground would still pass through the wall to get to the interior water line.

Given that, my thought is to keep it all inside, but maybe isolate it somewhat. I have excess cable, so think I'll mount an electrical junction box of some sort part way down on the concrete basement wall. The GB can then be removed from the floor joist above and mounted inside of that box, behind a cover, completely enclosed. I would then only have about a 3' vertical run of ground wire down to the water line.

Any thoughts on that idea?

Also just want to say this forum is the most useful site I've ever stumbled across on the web, THANKS!:up

Is this water line you speak of just a line to an outside faucet, or an inside appliance? If it is it does not meet code. The water line must be with in 5' of the entrance to the building. Another words the satellite system has to be grounded on the cold water line that feeds into the house with in 5' of the entry point.

 

[charlesrshell]

Is this water line you speak of just a line to an outside faucet, or an inside appliance? If it is it does not meet code. The water line must be with in 5' of the entrance to the building. Another words the satellite system has to be grounded on the cold water line that feeds into the house with in 5' of the entry point.

Well, there is an exception for commercial buildings for the 5' rule where conditions of maintenance and supervision ensure that only qualified persons service the installation. As far as I am concerned, I can do the conditions of maintenance and supervision for my house. Read on.

250.52 Grounding Electrodes

(A) Electrodes Permitted for Grounding

(1) Metal Underground Water Pipe A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system.
Exception: In industrial and commercial buildings or structures where conditions of maintenance and supervision ensure that only qualified persons service the installation, interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall be permitted as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system, provided that the entire length, other than short sections passing perpendicular through walls, floors, or ceilings, of the interior metal water pipe that is being used for the conductor is exposed.

 

[ksat1]

I believe my ground point meets code, without question. The #10 wire from the GB is clamped to the copper water line feeding the house, within 6 inches of it's entry through the concrete basement wall. That line runs directly from my well, which is located about 15' away from the house, and is buried at least 6'. The new placement of my GB would be directly above that point on the wall, requiring only about a 3' run of ground wire.