Curious B.J. what happened to your 5 receivers you blew up from a grounded dish, was it attached to the house or 100' feet away like in above post? i like you never ground any of my dishes, but don't really live in a lightning zone, and so far got away with it. When i install any dish if its attached to the house i think lightning will hit top of the house and mast first, and on the ground my thinking is lightning will hit nearest utility pole first, Also what blew up in your receivers power supply, processor, or the O/P transistor that feeds the LNB, curious and might help original poster, with his grounding choice.
Trench / Cable-runs, Advice?
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I can foresee on problem with burying cable directly in the ground. Gophers
I have a sandy type soil and gophers all over the place but so far I have had no problems.
I have a sandy type soil and gophers all over the place but so far I have had no problems.
My cables were directly buried 21 years ago and still work fine, even after a lightning strike in 2007. The cables survived, the connected equipment did not.
The BUD is not grounded beyond what the post contacts at the bottom of the concrete. The coax cables ground at the entry to the house. In my case, a sycamore tree was hit nearby and the actuator wiring carried the surge into the house.
The BUD is not grounded beyond what the post contacts at the bottom of the concrete. The coax cables ground at the entry to the house. In my case, a sycamore tree was hit nearby and the actuator wiring carried the surge into the house.
I started with a single 2-inch PVC pipe with All-In-One and some spare RG-6 cables for two or three dishes. That was 15 years ago, and has since been replaced by two separate projects: one is a 3-inch PVC run across the yard, and a later 4-inch PVC. At one time we had over 20 antennas separately connected, and almost ran out of wires (thank goodness for DiSEqc Switches). The 4-inch tube was about 80 feet long, using at least 15 conductors of RG-11. RG-6 jumpers connected under the "tower" to each LNB or LNBF connection to a dish, and the "house" end typically has 20-30 feet of RG-6 to the actual equipment.
Use of RG-11 allowed much more freedom to extend DiSEqC networks at the antenna farm without worry of cable length, where an additional 80 feet of RG-6 on each might have been a problem. Most of the RG-11 was acquired "cleaning up" after a national cable show eight or nine years ago.
Use of RG-11 allowed much more freedom to extend DiSEqC networks at the antenna farm without worry of cable length, where an additional 80 feet of RG-6 on each might have been a problem. Most of the RG-11 was acquired "cleaning up" after a national cable show eight or nine years ago.
I have always heard that it is very bad practice to ground the dish. I have always heard it will basically turn the dish into a lightning rod, and will actually cause it to attract electrical charges which will then work their way into the LNB and coax to damage the receiver.
I agree with grounding the coax, that seems to be NEC but, don't know the specific rules for the dish itself. I know that my dish is only grounded if it gets it's ground by being mounted to a metal fence post. Not sure how good of a ground this gives this dish due to the concrete, but, the end of the dish is touching the ground.
I've said it before and I'll repeat - when there's enough voltage potential to throw a mile-long arc between the ground and the clouds - it will do pretty much whatever the #3!! it wants to.
Now, that being said, all you can do is try and guide it AWAY from your home.
I'm NOT an expert on this and don't personally know anyone who is, but, from what I've gathered in all the articles I've read, what happens is someone grounds their dish with a ground rod but fails to bond that to the service entrance ground.
When the surge hits, the voltage potential between the antenna and the home is suddenly ump-teen million volts and much of the surge flows through the communication lines and into the equipment... even with grounding blocks there is still enough voltage across that it damages the equipment...
Now, if the ground rods are bonded together, that provides a better path to ground and brings the voltage potential between the antenna and the home pretty much nil.
For anyone who's interested, I've used Mike Holt's website (Google is your friend) as a guide for my stuff.
A good article covering all of this can be found here... hxxp://ecmweb.com/mag/electric_dont_signals_crossed/
Just my 2 cents - take it for what it is...
Now, that being said, all you can do is try and guide it AWAY from your home.
I'm NOT an expert on this and don't personally know anyone who is, but, from what I've gathered in all the articles I've read, what happens is someone grounds their dish with a ground rod but fails to bond that to the service entrance ground.
When the surge hits, the voltage potential between the antenna and the home is suddenly ump-teen million volts and much of the surge flows through the communication lines and into the equipment... even with grounding blocks there is still enough voltage across that it damages the equipment...
Now, if the ground rods are bonded together, that provides a better path to ground and brings the voltage potential between the antenna and the home pretty much nil.
For anyone who's interested, I've used Mike Holt's website (Google is your friend) as a guide for my stuff.
A good article covering all of this can be found here... hxxp://ecmweb.com/mag/electric_dont_signals_crossed/
Just my 2 cents - take it for what it is...
that strike me as . . .
I'm glad you brought up that theory: ground the dish, but then bond it to the house ground.
I'd read about it before, as a way to prevent a voltage spike being generated across your lawn for the distance between your dishes and home.
This probably depends a lot on various factors:
- how far your dishes are from your house
- how much higher your dishes are than surrounding structures
- whether there are high structures between your dish and home, which might attract a strike
- ground makeup as well as moisture content
I'll be relatively safe, in a low spot with taller trees, power poles, and other things to strike.
And none on the short path to my home.
But regardless, I was wondering:
- what size wire would you use for bonding?
- should you run it in the same (plastic) conduit as the RF cables?
- if not, then where & how?
- how much is a roll of 1/4" copper tubing you put in ice-makers with?
I'm glad you brought up that theory: ground the dish, but then bond it to the house ground.
I'd read about it before, as a way to prevent a voltage spike being generated across your lawn for the distance between your dishes and home.
This probably depends a lot on various factors:
- how far your dishes are from your house
- how much higher your dishes are than surrounding structures
- whether there are high structures between your dish and home, which might attract a strike
- ground makeup as well as moisture content
I'll be relatively safe, in a low spot with taller trees, power poles, and other things to strike.
And none on the short path to my home.
But regardless, I was wondering:
- what size wire would you use for bonding?
- should you run it in the same (plastic) conduit as the RF cables?
- if not, then where & how?
- how much is a roll of 1/4" copper tubing you put in ice-makers with?
- what size wire would you use for bonding? I use at least #6 or 2 #8 parallel. I think NEC says minimum #10
- should you run it in the same (plastic) conduit as the RF cables?
- if not, then where & how? Not in the conduit... not sure if it's a good idea to run it parallel with it or not... myself, I'm doing direct-burial and making an arrow-straight shot from the closest dish to the service entrance ground.
The coax enters at a different point and it is grounded to the house ground at the entry point (outside the house). Good, bad, ugly... I really don't know - gray areas abound!
- how much is a roll of 1/4" copper tubing you put in ice-makers with? I honestly have no idea... one thing I've never installed! I have one tho...
- should you run it in the same (plastic) conduit as the RF cables?
- if not, then where & how? Not in the conduit... not sure if it's a good idea to run it parallel with it or not... myself, I'm doing direct-burial and making an arrow-straight shot from the closest dish to the service entrance ground.
The coax enters at a different point and it is grounded to the house ground at the entry point (outside the house). Good, bad, ugly... I really don't know - gray areas abound!
- how much is a roll of 1/4" copper tubing you put in ice-makers with? I honestly have no idea... one thing I've never installed! I have one tho...
Pretty much the power supplies got fried. One of the receivers wasn't attached to grounded dish, but happened to be sitting on top of it.
The dish in question was a DTV dish I didn't install myself. It was located next to my power meter/power pole, and there is a power company ground rod there which the DTV installer used to ground the dish. I had previously lost 2 DTV receivers attached to this dish during 2 different storms where we didn't have particularly nearby strikes, but the last straw was a VERY close strike, which scoured the rust off the pipe in my water well. I have a bud and 2 3' FTA dishes near the DTV dish, and the receivers attached to them weren't harmed, but the 2 DTV receivers I had on the grounded dish were fried. Plus, I was sitting next to those receivers at the time, and a spark jumped between the DTV receiver and the FTA receiver sitting on top of it.
My opinion is that there should be only one ground point, and if you're going to ground the dish, the ground at the dish must be equivalent to the service ground, but without excessive expense, in most cases that isn't practical or even possible for most of us. I don't think any size wire run out hundreds of feet to a dish would qualify as making that dish bonded to the service ground. Plus, what do you ground on the dish? Just the pole? Do you bond the pole to the mount (via dissimilar metal?)? Do you bond the mount to the motor, to the dish? It would be nice to have everything effectively bonded to the service ground, but I really believe that it really can't be done for 99.99% of us. So the next best option is to have the coaxes grounded to the service ground where the power enters the house. I believe that properly grounding a dish is extremely difficult, and that the best efforts of us amateurs to ground a dish only make things worse. Just my opinion, and I certainly don't want people doing what I do, but I think that every installation is different, and what is best for one isn't necessarily best for others.
What exactly is meant by bonding? I have seen clamps screwed tightly together and exothermic fused grounds.
Any devices or techniques which are listed and approved for the purpose. There are listed bonding clamps which are approved for that use. Exothermal bonds are generally accepted as the best . "Cad welding", for example.
Bonding is the act of fusing the grounds together. So, when you weld/clamp/otherwise connect the grounding wire from the antenna to the common grounding post, that is bonding.
If one wanted to ground the coax only and the house service ground is nearly 200' feet away (on the other side of the house) what would be a suitable alternative?
Use a ground rod located at the dish or install a ground rod outside at the house at the point of entry and ground the coax there?
The grounds need to be bonded, otherwise you run the possibility of having a voltage differential between them.
Agreed - I firmly believe it would be better to NOT ground the dish at all than to have it grounded and not bonded. The coax can be grounded when it reaches the house (I would do it outside, before entry into the structure, but that's just me...)
Ground blocks at both ends are a good idea, won't help you with a direct hit, but will shunt away any nasty spikes from a nearby strike.
Used to work for DN, #10 ground wire from the ground block at the house to the electrical service ground is required. Also dual RG6 to the dish with the ground tracer tied to both the dish and the ground block at the house.
Used to work for DN, #10 ground wire from the ground block at the house to the electrical service ground is required. Also dual RG6 to the dish with the ground tracer tied to both the dish and the ground block at the house.
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