Follow-up grounding questions

[raylock]

A Dish tech came today to ground the system that they did not ground when it was installed. I have the following questions:

One set of lines enters the house at one end of the house and another set enters at the far end (for a 322 and a 522). The Dish tech said that only one set of lines needs to be grounded. He said that by grounding one set of lines the entire system will be grounded. Does this sound correct?

The tech said that the dish itself does not need to be grounded. The Sadoun document someone referred me to says that the dish and the coax must be grounded. The Panamax Technical Article says that the NEC APPEARS to require bonding the satellite dish grounds to the house ground. Am I off base to insist that the dish be grounded to the same ground as the coax?

The Dish tech was going to ground the coax to an air conditioner box which is attached to an air conditioner setting on a concrete slab. It is not grounded other than by the ground wire in the 220 volt line connected to the internal panel. Is this adequate? The ground wire in the air conditioner line is probably no 12 and is smaller that the #8 recommended. When I objected, he was going to ground the ground block to a metal conduit on the outside of the house that that is just a weather shield for an upstairs outlet but not grounded. I told him that I believed the ground needed to be bonded to the house service. That is about 25 feet from the point where the dish lines enters the house. He said they could not do that because it was more than 10 feet from the entrance point. Does that make sense? So far they have installed a grounding block but it is not grounded to anything. Based on my objections, the tech arranged for a quality control tech to come out on Tuesday to discuss it with me.

Sorry for all of these questions. It seems that this is harder than it should be or else I am going off half cocked. I would really appreciate any comments. Thanks!

Ray

 

[JWC]

There are no simple "technical" or "code" answers here, but this is my 2 cents opinion. When they installed my system I had my own ground rod installed (by me in advance). I asked the tech what the rules were. He said that they would not install a system that did not have a ground nearby, but that they would run a small gauge wire to the nearest available ground, including a grounded appliance such as a compressor.

That said, this is my best opinion on the need for grounding. First, grounding (even the best direct link via a heavy gauge braid) will not protect any dish or receiver against a direct or near by lightning hit. It will provide some benefit for a hit somewhat distant that has caused a "low level" EMP link, but in general you cannot protect against lightning. So what else might grounding do as a benefit. Not much, it would drain any static charge that accumulated because of a number of reasons. It would provide some electrical path where a GFI circuit might detect and turn off to potentially save the Rx from a non lightning issue. It might create or eliminate a ground loop. BUT there are very few reasons why not to ground the unit. But all of those reasons do not require an extensive ground, only an electrical path to the power grid. For me, I prefer a little bit better than that and would recommend you drive in a ground rod yourself near the location of the dish or dishes. It is not a big deal however. Only my willingness to do this little extra.

 

[volkodav]

the dish and all the lines to the receivers have to be grounded no mater what. if you put your own ground rod make sure it is over 4 ft we use to put in 8 ft. about 4 years ago we stop to many damages. and if you put in ground rod it have to be connected to the main ground rod of the house.

we ground dish and receivers to water pipe, or electric meter, or main ground wire.

 

[HCI]

http://www.dbsinstall.com/DNI/DNI_Standards_2.htm#400H

Grounding. All Grounding shall meet the following requirements, NEC and all local codes.
1) All grounding conductors shall be bonded to one of the following NEC approved bonding locations:

a. The building or structure grounding electrode system as covered in NEC 250.50.
b. The grounded interior metal water piping systems within 1.52m (5 feet) from its point of entrance to the building, as covered in 250.52.
c. The power service accessible means external to the building, as covered in NEC 250.94.
d. The metallic power service raceway.
e The service equipment enclosure or
f. The grounding electrode conductor or the grounding electrode conductor metal enclosures; orIf the building or structure served has no grounding means, as described in NEC 810.21(F)(1), to any one of the individual electrodes described in NEC 250.52; orIf the building or structure served has no grounding means as described in 810.21 (F)(1) or (F)(2), to an effectively grounded metal structure or to any one of the individual electrodes described in 250.52.

Note: Ground blocks are not an approved bonding location. Connecting a 17 AWG CCS mast ground conductor to a coax ground block, thereby piggy backing the mast ground onto a 10 AWG copper coax ground does not meet NEC requirements. Both the mast ground and coax ground conductor are required to be bonded to an approved NEC ground bonding location.
The "Piggy backing" of ground conductors is discouraged, but is accepted as an industry standard practice and therefore acceptable to meet DNI Standards.

 

[chadzx11]

Your conduit is covered under "D" and should be grounded. Additionally, most of those breaker boxes for AC units have a ground lug in them similar to what you might find in a real breaker box. If it has several lugs you can go into one of them through a knockout plug, or if it only has a single ground lug, you can install a ground lug to that box (it just screws, unless you can find an unused bolt hole), or you could use a split bolt to tie your dish to that ground wire. That box is supposed to be considered part of your race way as well. I would never do a chasis ground on an AC or any other appliance, though. And I have run across that in the field.

When I ground, I am more concerned about static electricity than lightning. I'm no electrician, but if your dish takes a direct hit, a #10 ground wire ain'g gonna save you. All dish requires is a #10 from the ground block to the ground. From the dish to the ground is generally the messenger #17 or whatever.

 

[raylock]

Education in grounding

Chadzx11, The air conditioner line is a Romex line from the panel to t he exterior wall where the air conditioner is located. The power line is #8 but I'm guessing the ground component is more like a #14. It seems to me that it makes more sense to run a #8 or #6 ground wire about 25 feet to the service ground rather than relying in a 40 foot run of #14 to the panel and thence to the service ground. Yes, the external conduit should be grounded, but it isn't. A previous owner ran a line for a new outlet on the second floor up the outside of the house and encased a Romex wire in this metal conduit.
Volkodav, thanks for the suggestion that ALL lines entering the house should be grounded. That was my thought. I may have to work to convince Dish or just do it myself.
The Tate and JWC, thanks for the input and education. This house is about 50 years old so the only really good common ground is the service ground. Water pipes exit in the opposite direction. JWC, I may be too worried about lighting since as you point out there is not a lot you can do about a really close strike.

Thanks all for the input.

Ray

 

[bhelms]

Raylock - You got it - DIYS !! The nearby 8" ground rod is a good idea IF you can drive it all the way into the ground. (Not possible in many rocky areas.)

I'd vote for #10 or heavier solid copper wire from each ground block and the dish itself to the main service panel. Protect the exterior mechanical connections with a good silicone grease or similar to prevent corrosion. Put the groundblocks in a housing or otherwise protect them from the elements. Don't forget to provide drip loops. In a 50 y.o. house, you'd be wise to check all outlets for solid grounds as well. Use a high quality surge suppressor at each equipment site and plan to replace them every several years.

As JWC mentioned, there is no protection from a direct hit. Make sure you have good homeowner's insurance, preferrably with replacement cost guarantees! The installer's statement about the 2 remote cables already being grounded by the system would bear-out with a DC ohmmeter, but that would not protect you from any quick surge, like EMP, peculiar to those cables.

You have learned well, Grasshopper! Be your own QC Tech and follow your own instincts...!

 

[abricko]

What about surge supressors with COAX / SAT / Phone protection? Are those also recommended... seems to me that would be the last line of defense (path for travel) before entering the receiver / tv.

 

[HCI]

abricko.

If you use a surge then it has to be set up for satellite. I would not recommend it because most of the time when people have a surge before the receiver they end up haveing a service call, because the surge is not rated to let the power "that the receiver sends" to power the LNB through. You can put one in behind the receiver but it will not do much good.

 

[raylock]

Great Dish Service

Today a Dish supervisor came to see what the problem was. He immediately agreed with my thoughts about grounding (most were based on the posts above) and proceeded do the work properly. He also examined the work that had been done earlier in the week and 15 months ago when the dish was installed. He identified several items which needed to be corrected. For training purposes he took pictures of all issues before and after the correction had been made. He filled out a check list of all the work done previously marking all of the elements pass or fail. This guy was a true professional who was more interested in getting it right than in just getting to the next job. There are really good people in most organizations. You just have to be lucky to find them sometimes. Thanks again for all of the advice received on this forum.

 

[dishcomm]

A Dish tech came today to ground the system that they did not ground when it was installed. I have the following questions:

One set of lines enters the house at one end of the house and another set enters at the far end (for a 322 and a 522). The Dish tech said that only one set of lines needs to be grounded. He said that by grounding one set of lines the entire system will be grounded. Does this sound correct?

The tech said that the dish itself does not need to be grounded. The Sadoun document someone referred me to says that the dish and the coax must be grounded. The Panamax Technical Article says that the NEC APPEARS to require bonding the satellite dish grounds to the house ground. Am I off base to insist that the dish be grounded to the same ground as the coax?

The Dish tech was going to ground the coax to an air conditioner box which is attached to an air conditioner setting on a concrete slab. It is not grounded other than by the ground wire in the 220 volt line connected to the internal panel. Is this adequate? The ground wire in the air conditioner line is probably no 12 and is smaller that the #8 recommended. When I objected, he was going to ground the ground block to a metal conduit on the outside of the house that that is just a weather shield for an upstairs outlet but not grounded. I told him that I believed the ground needed to be bonded to the house service. That is about 25 feet from the point where the dish lines enters the house. He said they could not do that because it was more than 10 feet from the entrance point. Does that make sense? So far they have installed a grounding block but it is not grounded to anything. Based on my objections, the tech arranged for a quality control tech to come out on Tuesday to discuss it with me.

Sorry for all of these questions. It seems that this is harder than it should be or else I am going off half cocked. I would really appreciate any comments. Thanks!

Ray

As I understand them, here's the straight dope on grounding...According to DN specs, all grounds must be to NEC code....The folllwing are the ONLY grounds acceptable to DN.....House gnd(meter base) either the #6 gnd wire or the meter boxitself..Some meters have screws at the top of the box that I sometimes use if the gnd wire is hidden behind brick or the siding..Next....the A/C cutoff switch box....This is bonded to the eletrical system of the home..you may run a self tapping screw into the box OR CAREFULLY drill a hole into the side of the switch box and use the ground bar inside...Next, a cold water copper pipe. Preferably the pipe that comes right from the water meter...VERY IMPORTATNT!..The ENTIRE WATER SYSTEM MUST BE CONTINUOUS COPPER....Otherwise the piping is NOT an acceptable ground.....You may also use a pigtail wire connected to the ground screw of an electrical fixture such as an outdoor elect outlet or light fixture..Finally, an "electrical raceway" or conduit provided the conduit goes to a metal junction box or meter or an ac cutof switch....on the BX cable sometimes seen going from the cutoff switch to a heatpump or ac unit, some say this is ok others say it is a no no..I have never failed a QC because I used that as a gnd so go with it....On a mobile home the metal frame is also an acceptable ground...Acording to NEC the frame of a mobile home must be bonded to the elect gnd of the home..
Myths....the CASING of a furnace or outdoor ac unit..No no!....A gas pipe..NO no never never....
Now, on to your situation.....BOTH sets of lines MUST be grounded..Think about it...if you ground one set that has no metal contact with the other, how could the uncontacted set be grounded....DN specs require the dish be grounded as well. on new connects and dish movers I will always gnd the dish..This is done with the standard messenger gnd wire on that style of cable..If I am on a service call and notice the dish is not grounded, I will gnd it only if it is a quick job..I won't spend time and money for the cable re doing a job that i'm not going to get paid for...I just have my dispatch put it into the notes that the dish isn't grounded and the only way to do so would be to install all new cable...I just won't do that for a service call fee. I will lose money on the job betwen time and materials.
If the "weather shield" you spoke of is not bonded, it is NOT an acceptable gnd..The tech is WRONG!..Also the 10 ft thing your tech spoke of is pure horse sh*t..The only restriction on the gnd wire length is as long as the gnd wire is shorter than the shortest run of coax to the first receiver..For example, if the run to your first receiver was 30ft of coax, the 25 ft run to the nearest acceptable gnd is ok....Now, just to clear one thing up, I keep my gnd runs under 25 feet..If I have to, I will just run more coax to get near a gnd...If a tech doesn't want to do this and ends up with a non spec gnd, he is just being lazy...Call DN to get the number of the contractor or installers office and report the problem directly to them...We get custs calling our office all the time..Dish gives them the number..Ususal;ly it is acust looking for waht time the tech will be at their home....But for this purpose the supervisor will want to know their tech did not do a job properly..If dish gets complaints about a contractor, Dish will pull work from that contractor.....So it is in the best interest of the contractor to make sure his techs are doing the job properly...

 

[HCI]

Some meters have screws at the top of the box that I sometimes use if the gnd wire is hidden behind brick or the siding..Next....the A/C cutoff switch box....This is bonded to the eletrical system of the home..you may run a self tapping screw into the box OR CAREFULLY drill a hole into the side of the switch box and use the ground bar inside...

You must have balls as big as coconuts.

 

[dishcomm]

Chadzx11, The air conditioner line is a Romex line from the panel to t he exterior wall where the air conditioner is located. The power line is #8 but I'm guessing the ground component is more like a #14. It seems to me that it makes more sense to run a #8 or #6 ground wire about 25 feet to the service ground rather than relying in a 40 foot run of #14 to the panel and thence to the service ground. Yes, the external conduit should be grounded, but it isn't. A previous owner ran a line for a new outlet on the second floor up the outside of the house and encased a Romex wire in this metal conduit.
Volkodav, thanks for the suggestion that ALL lines entering the house should be grounded. That was my thought. I may have to work to convince Dish or just do it myself.
The Tate and JWC, thanks for the input and education. This house is about 50 years old so the only really good common ground is the service ground. Water pipes exit in the opposite direction. JWC, I may be too worried about lighting since as you point out there is not a lot you can do about a really close strike.

Thanks all for the input

Ray

Custs sometimes ask about lightining..I tell them that if the dish takes a direct hit I would worry about far more important things than the sat system..Nothng man made can stop lightinng....at least as far as I know..In fact if we could harness the immense power of lightining we could save bazillions on elctrical generation for home use.....and we could use use it to blow the sh*t out of our miltary enemies.....

 

[raylock]

Dish did a good job

The guy today was a Dish Network employee. He handled it well. As I said, a professional who wasn't interested in cutting corners.

Best
Ray

 

[BrettTRay]

Custs sometimes ask about lightining..I tell them that if the dish takes a direct hit I would worry about far more important things than the sat system..Nothng man made can stop lightinng....at least as far as I know..In fact if we could harness the immense power of lightining we could save bazillions on elctrical generation for home use.....and we could use use it to blow the sh*t out of our miltary enemies.....

First of all. Cell towers, tv broadcast towers, radio broadcast towers are all at least a couple hundred feet tall and are usually on top of mountains. They take many strikes a year. How do you think they stop it? Direct hits can be stopped but in this case you would have to spend the money on the right equipment to stop it. Not the kind of money you would want to spend to protect a few hundred dollars worth of dish network equipment though. Second thing is with home based satellite dishes its not the direct hits that you have to worry about. Lightning can strike from long distances from your dish and still do damage. I would say out of the thousands of damages caused from lightning, that only a handful came from a direct hit. I think everyone that installs should read stuff like this http://www.harvardrepeater.org/news/lightning.html

 

[abricko]

Or...

Or they're made of glass (and well insulated)!

You must have balls as big as coconuts.

 

[bhelms]

That link BrettTRay provided certainly gives an in-depth perspective on the lightning protection subject! And it does give some hope that a properly designed system can indeed "stop" lightning, or more correctly, divert it sufficiently to ground so as to avoid damage to the attached equipment and structures. It all comes down to a question of practicality. Even tho' a typical subscriber is not likely to invest in a "proper" system, there are some reasonable, low-cost measures that can help provide substantial protection from "near-misses".

What the average subscriber or installer can take from that dissertation:

1) All cables entering the structure must be solidly grounded and preferrably to the same point. For RG6 this means using grounding blocks which actually only protect the outer shield, not the inner conductor. (I have a "spark-gap" protector in my RG-8/U lead-in - is there anything like that for RG-6 ??)

2) Grounding bonds need to be low impedance which is both low DC resistance and equally important, low inductance. This means at least heavy gauge wire or preferrably flat straps, short lengths, minimal gradual bends, etc. These must be mechanically bonded to the central grounding point, free of breaks and solder joints, protected from corrosion, etc.

3) Coupling between cables on the antenna side and equipment side of the grounding blocks must be minimized to prevent induced EMP, which is not likely an issue in a home installation. Just don't run "inside" and "outside" cables in parallel.

4) Any system less than the ideal system detailed in the link will likely result in equipment damage in the case of a direct hit. Since an "ideal" system is not likely practical for the average subscriber, make sure your insurance is up-to-date!

Another 2-cents worth...! (Boy, I need another roll of pennies today!)

(Sorry for the diatribe, but this is a subject of interest to me.)

 

[DucTape]

I always get a kick out of the " Did they ground it right" threads but at the same time do understand.
Yes they must do it properly because it's all we have to say we did all we could. When ya think about it ,trees are full of water and grounded better than anything else ever will be. They dissipate static charge like nobody's business but they get whacked every day to the tune of thousands per. So I guess what I'm saying is build a short house, preferably in the ground (pun intended).

 

[SimpleSimon]

I got a laugh out of the "we quit using 8' ground rods" post.

E* quotes NEC to cover their ass. Just like most electricians, the NEC has no clue how to handle low-voltage equipment, or why it should be grounded - or what is appropriate to get the job done.

Having seen both the effects of no grounding, and "decent" grounding in the #2 lightning strike county in the USA, both as a firefighter and an installer, I am confident that a 4' ground rod will do the job of draining static - which is the only reason it's needed. Oh - yes, both the dish and the coax needs to be grounded - they are electrically isolated from each other, so just one will not do the job. In fact, if you ground just the coax, there is a slight risk that a static build-up on the dish will discharge through the LNB, frying it.

Don't hand me that crap about the receiver being connected to house current, either. It may have applied in the bad old days, but no more. Remember when power tools all had to have 3-prong plugs? Same concept (but different technology).

 

[FSS3]

hey people i like this disscustion about grounding.Being dish instaler for about 5 years we herd it all.Mostly corporate staff:you have to doit this way or that".But onse you talt to the electrisian you'll get better info abot grounding.Like we can not ground dish inside of the house because we can't bring serge in to house .ALL DISHESH HAS TO BE GROUNDED OUTSIDE.