Grounding question

[JSLayton]

The guy who did my install took the ground wire that was paired with the two RG6 cables he ran from the dish all the way to my multiswitch and looped it around the mounting screw for the multiswitch. Is this the way it should be installed? I don't see how this grounds anything?

[Annihilator31]

If thats the only ground wire he hooked up, then it's not grouded at all, but your better off that way anyhow. Grounding DSS systems is code but does absolutely nothing but protect D* from lawsuites.

[Milominderbinder2]

Call DIRECTV and tell them that your installation does not meet local or national code.

Improper grounding has caused performance problems as well in many areas.

In addition, there are deaths every year due to floating grounds.

Here are the basics:

Grounding Requirements (http://www.dbstalk.com/showthread.php?p=941620#post941620)

I really am an Electrical Engineer (BS EE U of I).

Anyone who tells you not to follow the National Electric Code is giving you bad advice.

- Craig

[techrep]

I really am an Electrical Engineer (BS EE U of I).

Anyone who tells you not to follow the National Electric Code is giving you bad advice.

- Craig[/QUOTE]


I knew there was a reason that your posts were well organized, logical, detailed, precise, well documented, and difficult to implement in the field. ;)

!devil12: Shoulder :angel:

[Annihilator31]

All grounding a DSS system does, is introduce another point of failure. If your system is not grounded it will NOT affect your receiver performance. In FACT, some of the HD receivers have been known to have problems related to grounding. This is why we sometimes have to break off the ground in the electrical plug. Problem solved. I hear the argument of the Electrical Engineers, but their knowledge doesn't fully apply here. You want to know about REAL world sittuations, as the people who have been installing satellite systems for years. Grounding actually causes more problems! Anyone who wants to debate or argue this point with me, I will e-mail them pictures of a fully grounded system that was destroyed BECAUSE it was grounded!

[ThomasM]

Your system should be properly grounded for the safety of the equipment and YOU! All that grounding information in the front of each DirecTV manual isn't put there just to waste paper.

A properly grounded satellite dish installation should include a ground wire going to either a buried ground rod, a cold water pipe, or an approved electrical ground.

I serviced remotely located radio transmitters earlier in my career, and after a thunderstorm it was always the same scenario. Equipment not properly grounded got destroyed while properly grounded equipment survived.

[K4SMX]

All grounding a DSS system does, is introduce another point of failure. If your system is not grounded it will NOT affect your receiver performance. In FACT, some of the HD receivers have been known to have problems related to grounding. This is why we sometimes have to break off the ground in the electrical plug. Problem solved. I hear the argument of the Electrical Engineers, but their knowledge doesn't fully apply here. You want to know about REAL world sittuations, as the people who have been installing satellite systems for years. Grounding actually causes more problems! Anyone who wants to debate or argue this point with me, I will e-mail them pictures of a fully grounded system that was destroyed BECAUSE it was grounded!
As someone who has been erecting antennas since 1959, I can advise that this is dangerous claptrap. If grounding a receiver introduces problems into your system, I can assure you that it's not properly grounded. A receiver that has to have the safety ground lug removed off of the wall plug in order to work properly indicates further electrical problems that will require a qualified electrician to correct.

Any properly grounded receiver can still be destroyed by a lightning strike, so I don't need to see any photos. The point is, if you put an ungrounded dish antenna on your roof and thereby provide the primary path for a lightning strike directly to your receiver, you are risking a lot more than your receiver.

[techrep]

As someone who has been erecting antennas since 1959, I can advise that this is dangerous claptrap. If grounding a receiver introduces problems into your system, I can assure you that it's not properly grounded. A receiver that has to have the safety ground lug removed off of the wall plug in order to work properly indicates further electrical problems that will require a qualified electrician to correct.

Any properly grounded receiver can still be destroyed by a lightning strike, so I don't need to see any photos. The point is, if you put an ungrounded dish antenna on your roof and thereby provide the primary path for a lightning strike directly to your receiver, you are risking a lot more than your receiver.

The "Grounding Guru" has spoken!

[K4SMX]

The "Grounding Guru" has spoken!
There is little I've ever done to warrant guru status in any area, but I have dealt with these particular problems for a long time. Grounding electronic equipment to prevent actual damage from lightning is a very complicated subject which I never get into in these forums, but for which there is abundant technical information available. I have always been primarily concerned here with basic safety issues only.

[techrep]

There is little I've ever done to warrant guru status in any area, but I have dealt with these particular problems for a long time. Grounding electronic equipment to prevent actual damage from lightning is a very complicated subject which I never get into in these forums, but for which there is abundant technical information available. I have always been primarily concerned here with basic safety issues only.

You are to modest. Compared to most of us around here, the "guru" status is earned in this area.

[K4SMX]

I would add, the primary reason roof-mounted dish antennas are not struck more often by lightning comes down to one thing only: trees. There are a lot more of them...

[aim2pls]

All grounding a DSS system does, is introduce another point of failure. If your system is not grounded it will NOT affect your receiver performance. In FACT, some of the HD receivers have been known to have problems related to grounding. This is why we sometimes have to break off the ground in the electrical plug. Problem solved. I hear the argument of the Electrical Engineers, but their knowledge doesn't fully apply here. You want to know about REAL world sittuations, as the people who have been installing satellite systems for years. Grounding actually causes more problems! Anyone who wants to debate or argue this point with me, I will e-mail them pictures of a fully grounded system that was destroyed BECAUSE it was grounded!


ahhhh .... a man that actually knows what he is talking about

[aim2pls]

Your system should be properly grounded for the safety of the equipment and YOU! All that grounding information in the front of each DirecTV manual isn't put there just to waste paper.

A properly grounded satellite dish installation should include a ground wire going to either a buried ground rod, a cold water pipe, or an approved electrical ground.

I serviced remotely located radio transmitters earlier in my career, and after a thunderstorm it was always the same scenario. Equipment not properly grounded got destroyed while properly grounded equipment survived.



a 1000 foot high radio transmitter tower is a lot different from a 16-20 foot high sat dish

[aim2pls]

All grounding a DSS system does, is introduce another point of failure. If your system is not grounded it will NOT affect your receiver performance. In FACT, some of the HD receivers have been known to have problems related to grounding. This is why we sometimes have to break off the ground in the electrical plug. Problem solved. I hear the argument of the Electrical Engineers, but their knowledge doesn't fully apply here. You want to know about REAL world sittuations, as the people who have been installing satellite systems for years. Grounding actually causes more problems! Anyone who wants to debate or argue this point with me, I will e-mail them pictures of a fully grounded system that was destroyed BECAUSE it was grounded!

I can relate .... a friend was installing a commercial VSAT system in Louisiana with the assistance if an Electrical Engineer who had just set up a substancial grounding system for this type of installation (NPRM commercial roof).... following the procedures and specifications that he had developed ... they were installing the system .. grounding was completed .. all that remained was for the antenna to be pointed and commissioned ..... a thunderstorm approached .. they went inside .... apon returning to the roof ..... they found the mount was intact ... the dish had been blown apart from a lightning strike ...... it turned out that the dish had become the lightning rod for that area of the roof ... all installers that had installed that grounding system were then paid to go back and REMOVE the grounding system

[excalibur26]

Don't ground, play with fire. Grounding is not to protect against a direct lightning hit. It dissipates static build-up.

[Annihilator31]

I think the overall point is that there are pros and cons of grounding vs. not grounding. The fact is that there are more con's to grounding your system (in most situaqtions). Now another thing you have to keep in mind is the age of the house and it's wiring. Some areas have nice new homes that are far more up to codes, while in many other areas you have housing going back to the 1800's where proper household grounding is non existant.

And yes, a 1000 foot high radio transmitter tower is a lot different from a 16-20 foot high sat dish.

[raoul5788]

I think the overall point is that there are pros and cons of grounding vs. not grounding. The fact is that there are more con's to grounding your system (in most situaqtions). Now another thing you have to keep in mind is the age of the house and it's wiring. Some areas have nice new homes that are far more up to codes, while in many other areas you have housing going back to the 1800's where proper household grounding is non existant.

And yes, a 1000 foot high radio transmitter tower is a lot different from a 16-20 foot high sat dish.

This is simply not true and in fact dangerous. As the previous poster stated, the ground is there to eliminate static build up. What are your reasons for not grounding? This should be interesting.

[RobertE]

There is code.

There is the real world.

Many times the two don't exist in the same universe.

[Reggie3]

Call DIRECTV and tell them that your installation does not meet local or national code.

Improper grounding has caused performance problems as well in many areas.

In addition, there are deaths every year due to floating grounds.

Here are the basics:

Grounding Requirements (http://www.dbstalk.com/showthread.php?p=941620#post941620)

I really am an Electrical Engineer (BS EE U of I).

Anyone who tells you not to follow the National Electric Code is giving you bad advice.

- Craig
I too am a EE (75' Wash U) and the ground of the dish is only for lightning. The only ground needed is for electrical power at the plug.

My dish is not grounded (via Directv install)
'
If you have a good homeowners insurance - a lightning strike will take out more than just the dish even when grounded and your homeowners covers it all.

[AntAltMike]

The NEC is a fire and safety code. Grounding a mast makes it slightly less likely to be hit by lightning. Grounding a coax as near as possible to the point at which it enters a building makes it less able to sustain a shock potential and less likely to every carry enough current to start a fire. Neither will totally mitigate the effects of a direct lightning hit if one happens, but they make the lightning hit less likely and reduce fire and shock hazards under other circumstances, like if a live 110 or 220 volt line comes in contact with any exterior part of your antenna system.

Sometimes, a good safety ground is not a good technical ground. It usually is, but sometimes it isn't. If your NEC exterior grounds cause an audio or video hum, you can often remedy that with a strategically placed ground loop isolator.

[Annihilator31]

You want protection? Go buy a good Quality surge protector! None of MY 4 personal satellite dish's are grounded and never will be. They have always worked great. I use an APC surge protection system and I believe thats they best there is. If you want to eliminate static build-up, just use Static Gaurd! http://www.mystaticguard.com/

[Annihilator31]

There is code.

There is the real world.

Many times the two don't exist in the same universe.

Amen!!

[techrep]

There is code.

There is the real world.

Many times the two don't exist in the same universe.

You know your "stuff" RobertE but I don't want to explain that to the Fire Marshal or the insurance adjustor if they "have to" show up on one of my properties.

[excalibur26]

Nobody has given a solid reason not to ground.

[aim2pls]

You want protection? Go buy a good Quality surge protector! None of MY 4 personal satellite dish's are grounded and never will be. They have always worked great. I use an APC surge protection system and I believe thats they best there is. If you want to eliminate static build-up, just use Static Gaurd! http://www.mystaticguard.com/

I use SASD (silicon avalance suppressing diode) units from transtector .. granted they are a few hundred bucks apiece .. but worth it

[aim2pls]

Nobody has given a solid reason not to ground.

ok

hundreds (conservative number) of ungrounded dishes that i have installed have never been hit by lightning (direct or near)..... 12 that were grounded have been .... one the NEXT day

[Coffey77]

Grounding the dish has really nothing to do with "saving" the dish itself. It's to remove the threat of injury/death from electrical potential to earth (ground) by creating a path of least resistance through another mean besides your body. :)

[Stanley Kritzik]

There is little I've ever done to warrant guru status in any area, but I have dealt with these particular problems for a long time. Grounding electronic equipment to prevent actual damage from lightning is a very complicated subject which I never get into in these forums, but for which there is abundant technical information available. I have always been primarily concerned here with basic safety issues only.

When I was young, foolish and in college, a million years ago, I used to build all sorts of radio and electronics gear. One item was a photoflash strobe unit, when they were rare as commercial products, and I failed to ground a metal plug. I got 2,500 Volts, DC, arcing across my fingers, with burned skin at all my fingertips. I learned really fast about the merits of grounding.

Today, all electronic gear is 100% tolerant of grounding -- why take a chance on burning your house down, with the Missus, Kids and the dog all in it (and, you too)? Really important -- you could lose your HD screen, as well!

Stan

[techrep]

Let's keep in mind that nothing passes between the dish and the receiver except RF and and low (13E and 18E) voltage switching signals. Short of a powerline falling on the dish, I can't think of a way for the dish to present a shock hazard. When grounding a dish, the primary goal is to disipate static electricity making a direct lightning strike less likely. I do admit that the ground provides a path to the dish, and everything downstream of it, in the event of a nearby lightning strike.

[excalibur26]

What if the dish is ground to the electrical service? This is my preference, not a separate ground (rod).

[K4SMX]

All dishes are "grounded" as soon as you connect your coax from the dish to the receiver. So without a primary path to get it started directly to the earth by means of a direct-to-earth ground wire, lightning gets to travel destructively to a lot of different places to dissipate its energy. Say your coax runs straight from your roof-mounted dish into your attic. A large amount of energy can be expected to to travel on your coax, since that's the best of a lot of so-so routes to ground. Next it gets to your receiver, after possibly shooting off to any nearby attic wiring on the way. You might have your coax run through a surge suppressor (which is not really designed for satellite frequencies anyway in most all cases.) Either way, after destroying all the connected equipment it encounters at this point, it's on to your house wiring and your electrical panel box. That can have interesting results as well. A couple of runs of RG-6 can actual carry quite a bit of current before it vaporizes. Then where does the remaining undissipated energy go? Not a pretty picture. Is this what you want?