AVS Forum banner
Status
Not open for further replies.
1 - 16 of 16 Posts

·
Registered
Joined
·
73 Posts
Discussion Starter · #1 ·
Hello all,


I have what may seem like a stupid question, but here goes:


I have an oval dish with a 4X4 multiswitch and 4 receivers.


Obviously I have 4 leads coming from the dish:


2 of the leads come to a dual grounding block before entering the house, the block is grounded to a 4 foot grounding rod.


1 of the other leads comes to a single grounding block which is grounded to the same grounding rod, is this acceptable, or will this cause what they call a grounding loop or a short?


The 4th lead comes to another grounding block which is also grounded via a grounding wire, but to a separate grounding rod. This rod and the other rod are separated by about 35 - 40 feet.


One of my receivers keeps getting zapped (ie needs to be returned to manufacturer) for replacements. The weird part is the lead that goes into this receiver is one of the two leads coming from the dual grounding block, the other lead goes to a receiver which is unaffected and working perfectly. I swapped cables and such and am convinced that the receiver is fried. It keeps reporting cannot find satellite where I know there's sat signal on this lead based on connecting it to another receiver. Obviously, some receivers can be more suceptiple to voltage and surges than others.


Can this be attributed to the fact that two separate grounding blocks are commonly grounded to the same rod?


Any suggestions or theories would be most appreciated.


Regards

John
 

·
Registered
Joined
·
1,285 Posts
Are the grounding rods bonded to the electric service ground of the house?


Your equipment should NEVER be connected to grounding rods which are not connected correctly to the house grounding system.
 

·
Registered
Joined
·
5,605 Posts
Two earth grounds (two grounding rods) cause a ground loop. You only need a new grounding rod pounded into the earth if the first rod is no longer used, or accessible. Low volt items like cable, or dish can have a grounding block grounded to a cold water pipe.
 

·
Registered
Joined
·
73 Posts
Discussion Starter · #5 ·
hometheatreguy, so I guess my question am I correct in grounding each cable before it enters the house, or is that incorrect? Just to restate what I did originally, I have a dual grounding block wired to a grounding rod and a single grounding block grounded to the same rod, do I NOT need to ground one of these since the first is already grounded?


Thanks

John
 

·
Registered
Joined
·
5,605 Posts
It wouldn't be detrimental to ground two grounding blocks. What introduces noise is using multiple grounding stakes. A splitter can be used as a grounding block. When I did QC for Adelphia, the biggest thing I found were techs failing to ground a splitter, or block on a cold water pipe to save time on the job. Try replacing the grounding blocks with a new dual fitting block. Replace the ground wire and copper strap that attaches around the cold water pipe. Even though it is a misconception that grounding improves picture quality, audio quality, or functionality of either a digital cable box, or dish receiver grounding to earth is to send lightening surges and built-up static charges into the earth to avoid the energy to go into the electronics, per the NEC and FCC. To your questions: 1.yes, ground everything before it enters the house. 2.yes, ground both cables.
 

·
Registered
Joined
·
73 Posts
Discussion Starter · #7 ·
Thanks, I do have multiple stakes in the ground about 35 feet apart, so altogether, I have 3 grounding blocks and two rods/stakes. Can these stakes interfere with each other at that distance? What if I simply run grounding wire from all of the blocks to one rod, or is there a limit to the distance I can run the ground wire? Also, these are not going to the water pipes, these are on the complete opposite side of the house. I can replace two of these grounding blocks to one dual fitting, but I do have 4 runs of cable from the dish, can I just have two runs to one dual block, two to another, and ground both blocks to a common grounding rod. I'm attaching all of the ground wires through the one eyehole, is that incorrect, is there an attachment or something that I can attach multiple ground wires to a single rod? I hate to overwhelm you with all these questions, but you're the first person to answer me, maybe you're the only one who understands my problems :)


I do appreciate whatever help you can give me..


Regards

John
 

·
Registered
Joined
·
5,605 Posts
John, a home only needs one grounding rod. Just keep them all wired to the rods you have (since they are there). Yes, multiple ground rods have the potential to introduce noise into your electronics. Even the electrical and phone to the house requires only one common earth ground. It is fine to use 2 grounding blocks and run all the ground wire to one (central) grounding rod. Lowes, or Home Depot has copper grounding clamps for $5.00 (tell them what you want to do) that attaches to the grounding rod. Then insert all the bare copper ends of the ground wire from your new grounding blocks in the hole of the clamp and tighten. Yes, running all the ground wires through one eye-hole is fine, use silicone to keep water out of the home.

As far as cable isolators, do you mean the passive filters, or amplified ones? Isolation should only be used as a last resort. They are like a band-aid to a ground loop. Do everything you can first. Some line amps associated with isolators are actually more problematic. I have by-passed them sometimes and noise left and the picture became better in some situations. Let me know if you have more questions,

Scott
 

·
Registered
Joined
·
73 Posts
Discussion Starter · #10 ·
Scott,

Well, I have two 4 foot rods already hammered into the ground, not tied together, except for the coax runs from a common multiswitch satellite. From what I'm hearing, I will need to remove one ( that will be fun) and just run copper wire from the block I was grounding onto that one to another. Currently, I'm using aluminum wire, I suppose that's not a good choice, the guys at Radio Shack sold me a short spool of it, I will need to get some copper wire. Once I remove one of the rods, will I need to tie the remaining to the electrical ground already in place? The reason I'm asking is they are on opposite sides of the house, the dish is actually on the side of the house and I really don't want to move it, and the 110v service is on the opposite side, I haven't looked for where the grounding is, is there a simple way to look for it, also, what are the dangers of grounding to this, or should I just go hire someone who knows what they're doing for this?


What's really strange is this was working for about 4 or 5 days with no problems, then after it rained, the problems started, could the rain have caused some inherent problems or enhanced an already existing problem.


I'm about ready to go dig up one of the grounding rods tomorrow where I know I have two blocks grounded through the same eyehole and remove one of the grounding wires completely to see what happens. From what you're saying, probably won't make any difference.


Thanks again

John
 

·
Registered
Joined
·
5,605 Posts
Hi John, if I were you I would not physically pull the grounding rod out of the ground. Just by-pass it. You only need one. No, you do not need to run ground wire all the way to your electrical and phone ground (if you ever wanted to find the main ground to your home, look around the electric meter). If it were closer it would be OK and not harm anything. The cable companies use copper stranded soft wire for grounding. Dish Network and DirecTV use a solid copper wire. If the termination (ground wire ends) of the grounding blocks is exposed to water it would not matter. They do have rubber boots to protect the f-fittings for the coaxial cable ends. Rain can effect dish performance, but it is not in the grounds it is usually with the connections to the LNBs (install rubber boots on these connections for more reliable reception). Verify all the bolts are tight on the dish as well.
 

·
Registered
Joined
·
73 Posts
Discussion Starter · #13 ·
ok, so if I bypass one of the rods, and just tie all three grounding blocks to one grounding rod, that should be ok? Again, is it ok if these grounding wires touch as in the same eyehole on the same grounding rod. Also, will there be any contention between the electrical ground and the grounding rod I installed since the receiver A/C plug is grounded through the A/C outlet as well. Is it at all possible that the receiver that I'm having problems with is not fried and maybe just improperly grounded.


thank again

john
 

·
Registered
Joined
·
5,605 Posts
Sure, it would be OK to bypass one of the rods and tie all three grounding blocks to one grounding rod. They will all receive a ground to earth. Yes, it is OK having the grounding wires touch in the same eye-hole on the same grounding rod. No, there would not be a problem with the electrical ground to the home and the ground rod you installed. If you have to continually return the receiver there may be a alternating current (voltage) issue more than a grounding problem. Use a multimeter at the power outlet that the damaged receiver was plugged into and get some simple voltage readings on it. You may have to rewire that outlet. There are just three wires: hot, neutral and ground. John, I will catch you tomorrow at lunch, or in the evening I am signing off for the night. We will fix this problem.

Scott
 

·
Registered
Joined
·
73 Posts
Discussion Starter · #15 ·
Thanks Scott,

The outlet that this is plugged into services a Monster power bar, which is where the toshiba and several other components are plugged into, including another satellite receiver. I will take some reading out of the the outlet as well as the strip, I'm at work now so I'll let you know what I find tonight.


Thanks

John
 

·
Registered
Joined
·
1,450 Posts
Per code, if you have more than one ground rod in the house, they must be tied together by #6 or larger copper wire.


Or, you can just bond everything to the electrical system ground.


As others have said, if your house has metal water pipes, you can bond to the pipes (these will be bonded to the electrical service ground).
 
1 - 16 of 16 Posts
Status
Not open for further replies.
Top