Post mount dish installation

[Dbcurtis]

I will installing Dish Network equipment at my new home.
Due to the trees, I cannot put the dish on my house.
I will have to do a pole mount dish about 75ft from the home.
Installed will be a dish 500 w/ DP quad LNBF.
What are my grounding requirements?
The dish will be on a metal pole buried 4ft in the ground, should I ground the COAX as well?

 

[inwo]

Nothing else needed at dish. Code requires coax grd at entry to house.

 

[Dbcurtis]

That could be a problem, since I was going to run the Co-Ax underground in conduit with the conduit entering the home. Any Suggestions?

 

[Van]

Code from NEC requires that all external antenna be grounded including the satellite dish regardless of where its located at. The coax also must be grounded per code, you can ground both the dish and the coax inside the basement/crawlspace within 5ft of the point of entry to an approved ground source such as a cold water pipe that is copper and properly grounded itsself, the house ground at or near the electric meter / fuse box, an electrical conduit made of metal.

Many on here will disagrea on grounding when it comes to what has to be grounded and how, the best thing you can do is go to your local county office and talk to someone in the building permits and inspections office and find out what the local ordinances dictate because some municipalities will have stricter guidelines than that of the state or feds.

 

[bpickell]

I don't want to start some big argument here, but I really don't understand the point of grounding a dish at the house when it is mounted on a pole buried 4ft in the ground.

When lightning strikes it is seeking out a ground. Almost always it strikes the ground itself, which tells me that is a ground. So dish mounted on pole should be grounded.

Now if you run a 75ft grounding wire from the dish to the house I think you are just asking for problems. If lightning were to strike the dish I would think that you stand the chance of the spark jumping off the ground rod, even though physics tells me that the spark would never make it to the house anyway since it takes path of least resistance (the pole already in the ground.) Do you honestly think its going to travel 75 ft. up a 6 guage wire, when it could just go straight to the ground?

 

[inwo]

Common misconception!

Grounding is not intended as lightning protection. Purpose is shock protection. And as per NEC, to limit max voltage on the system.

 

[wobbie]

Curtis, do what Van says' you can get coax with ground attached to it. When pulling the coax thru the conduit pole a couple extra lines or at least a pole string for future references. I did the same with my dish, conduit under the patio before I poured the patio. I have two extra coax, two extra phone lines and two extra speaker wires, my detached garage is wired for satellite, phone and sound.

 

[rowemance]

When you put your Dish 500 or 1000 on a pole it is NOT GROUNDED your LNBF never touches the metal of the dish or the pole.

If it was a 18" dish it would be grounded at the dish.

You still have to ground the dish as it enters the house this is your most important ground as it dissipates the static electricity from your system. The old Hughes DTV receivers use to have a terrible problem with static discharge at the receiver.

Check with your local codes as how they want it grounded.

Grounding the Dish its self is really not that important due to the fact that the electronics on the dish are not grounded anyway on Dish 500 or 1000.

 

[bpickell]

ok that makes a little more sense, however I was taught in electonics that you always want to have the shortest ground possible. So why not ground it to the pole? 1ft ground -vs- 75ft ground.

Now another question. Does grounding the coax ground the dish? I would think not. although the coax does actually touch the lnb itself.

 

[rowemance]

You should use the shortest ground possible at the point of entry to the house not at the dish.

The dish ground really doesn't do anything except for a lighting strike or if an electrical line fell on it and then you would have bigger problems anyway.

The ground is to dissipate any static electricity from the system and to protect against power surge from the dish lines.

 

[Dbcurtis]

Wow, looks like I re-ignited a debate.
Thanks everyone for the suggestions!
I will be grounding at the house.

 

[Van]

Keep in mind that the requirements for grounding are set by the nec and by fed, state, and local municipalities IE goverment and we know how competant goverment can be when they buy $4,000. claw hammers. But to the idea of the pole mount being grounded because its in the ground thats not the case and anyone thats had a c-band dish can atest to after its been hit by lightning.

 

[SimpleSimon]

Someone already hit on the answer. D500/1000 LNBs are electrically isolated from the dish itself.

The 4' deep pole is definitely grounding the dish, but NOT the coax.

I would put a ground block at the dish, and ground it there, then I would ALSO ground the coax at building entry as already mentioned. Wouldn't hurt a bit to use coax with a messenger wire tied to the ground blocks at each end.

 

[rowemance]

Sorry a 4' pole mount would not be Legally grounded if grounded at all.

You dig a hole say 1' deep and fill with cement and stick a pole in the cement the pole is not grounded.

You dig a hole 1' deep and pound a 6' pole 2' below the bottom of the hole and fill around the pole with cement this would be grounded but not legally.

 

[bpickell]

You dig a hole say 1' deep and fill with cement and stick a pole in the cement the pole is not grounded.

Why not? Are you saying concrete isn't a conductor?

If it's not a conductor explain this one to me. I have an electric fence to keep my cats and dogs in my yard. If I go up to the fence and touch it while standing on my concrete driveway, I don't get shocked. If I take my shoes off and touch it again while standing on my concrete driveway, I get shocked. That tells me that the concrete that I am standing on is a ground.

Before you think I'm some kind of idiot that likes getting shocked. I didn't really shock myself I used a volt meter.

 

[rowemance]

Cement is not a great conductor or electricity.

Your ground was probably cause more by moisture than rock.

Did you ever wonder why your house is grounded to an 8' rod pounded in the ground and not just to a cement block with a wire attached to it?

 

[webbydude]

Another reason for grounding the dish AND the coax to the same ground is due to differences in electrical potential. Not all grounds are the same. I can go on and on about the physics of it all, but the overall point is, NEC states that all of the "grounds" have to be bonded together to prevent a floating ground situation.

 

[inwo]

Cement is not a great conductor or electricity.

Your ground was probably cause more by moisture than rock.

Did you ever wonder why your house is grounded to an 8' rod pounded in the ground and not just to a cement block with a wire attached to it?

Wrong!

NEC recognizes concrete as a grounding electrode in new code.

In fact I did it in my own house right after I got back from nec classes.

 

[webbydude]

Wrong!

NEC recognizes concrete as a grounding electrode in new code.

In fact I did it in my own house right after I got back from nec classes.

Not that I don't doubt you, but...can you post a link as to what section of the NEC states that it's kosher to use a concrete ground????

 

[ITK]

Not that I don't doubt you, but...can you post a link as to what section of the NEC states that it's kosher to use a concrete ground????

I cant point you to the NEC code, but i can tell you my building Inspector recomended this type of ground in my soon to be complete pole barn. I belive its called a Ufer ground..the spelling may be wrong on that but thats what he called it, YOUFER..