The satellite dish is on the roof. I would ideally like to bring the two cables right thru the roof into the attic, as I have full roomy easy access to the attic and can readily route the cables from there. Intructions with the dish only describe bringing the cables down the roof and thru a sidewall. Does anyone know a good trick for passing cables thru the roof (shingles and all) without creating a leak?

I've obviously put the satellite mounting bolts thru the roof, with liberal sylicon sealer around and under them. Two cables won't exactly fill a hole, especially if the cable ends have to fit thru the hole first.

Secondly, what's the best trick for grounding it all, if I go right into the house? In the old days when I had a roof antenna I used a radio shack cable grounder. The antenna cable passed thru it. It was plugged into a grounded wall outlet. Is there a similar device for satellite cable? Am I at serious risk if the dish remains ungrounded?

Thanks in advance,

Dave

You DON"T want to bring that ground into the House !!
Instant Health & Safety Hazard !!!!!!
It should be grounded on the outside.

OK, Dave. Are you basing your advice on personal experience, something you heard/read somewhere, of an actual education in the physics of electricity?

For example, if the outlets in my house are properly grounded, why is this ground more risky to use than the "ground" ground outside? I read at some time in the past a theory for lightning rods placed on houses.... Although they would direct a lightning strike around the house and to the ground, they tended to keep the air around the house less "charged" and so reduced or eliminated lightning's tendancy to strike the house.

I don't doubt your sincerity, Dave. I just want the REAL truth, and not the propigated myths. Do you know if what you said is the real truth, or is it just something you heard and are passing along?

In either case, thank you very much for your response.

David B.

David B.

Basically you want the ground to stay outside so that if lightning strikes, it takes the path of least resistance. Think about it. Sure your inside outlets are properly grounded, but a direct strike travels to the gound through all the cables connected to that it strikes (i.e. your cable). Most times if you have a surge protector on your equipment that will prevent any damage (except the protector will be fried). If you can prevent the energy even reaching that point, that is best. The ground used on power masts on your house (used for above ground power) is a pipe clamp on the mast tied to a single strand 12-14 guage copper wire clamped to a piece of rebar driven six feet into the ground (I used to be an electrician). Something like this could be used for your situation. Just an observation from someone who has seen damage from direct lightning strikes.

Thank you, Tom.

David B.

I have been installing cable and satellite for 20 years and I avoid going thru any roof unless you install an emt pipe with a weatherhead and the proper flashing around it(similar to any vents you have). Sometimes you can get wires thru an existing vent's flashing on the downslope (depends on the roof material and flashing). Other than that just route the cables to an existing vent at the eave or side peak. Grounding should be the shortest possible interior or exterior. Primary target is the power mast (out a ground block near the dish), secondary a water pipe or ground rod. I usually mount the dish near a ground if at all possible.

1) if you want the lines into your attic, don't go through the roof, just bring them through the side of the attic closest to your satellite

2) the way you should ground it is to run a ground to the electrical ground

Thank you, guys.

What I ended up doing is put the dish about 4' from a gable edge of the roof. I ran the cables to the edge, down about 3' to the grounding block (with a drip loop) then into a hole (after another drip loop) which I sealed with sylicon around the cables. A heavy guage aluminum wire runs from the grounding block down to an 8' length of rebar that was sunk 7' into the ground. The utilities are on the opposite side of the house, with no realistic way to get this ground to a water pipe or electrical box pipe.

Using a multimeter I found the metal dish to have continuity with the cable casing so I did not run a second ground from it. Inside the house the cable runs through a small box that has plugged into an outlet and grounds the cable casing to the house electrical ground.

If I get hit with lightening, I'll let you know.

Dave

I have an interesting story about grounds. My dish sits under a deck, right at ground level. While under warranty I had a failure after a lightning storm. A tech helped me isolate the problem to the LNB at the dish. He then asked if I had grounded the unit per the instructions. I proudly told him that I had driven a six foot copper rod within several feet of the dish and installed it just as documented. He paused, then proceeded to tell me that this is what likely caused the LNB failure. He said it was actually safer for the equipment to tie the ground back into the house wiring and not use the separate ground, something to do with surges during storms.

A rod driven into the dirt is going to have a different ground potential than the house ground at the main box. It is the difference in potential that can cause problems

Michael,
Does code in your area require a ground rod at the electrical service entry point? Ours does, I was surprised that there could be a potential difference between two ground rods located maybe 75 feet apart.
Doug