[ctblue]

Before I get into the background information, my questions are: "Is there any way to bond ground rods by way of a subpanel (for which I would hire an electrician)? Assuming, instead, I need to connect the rods directly, do I need to bury the wire that bonds my 2 ground rods? If not, can this bonding wire be attached to the outside of my house (up walls and under eaves)?"

The background information is as follows:
* My goal is to bring different phone and cable lines into my house.
* The 2nd ground rod would be installed for phone and cable grounding only.
* I put an addition on my house. The old part of the house is on a slab. The addition has a basement.
* The electrician installed a subpanel in the basement of the addition that feeds off the main panel. The original/main panel is located in my garage, far away from the addition. This is where the first/original grounding rod is located.
* The subpanel is on the opposite side of the basement from the future demarc point for phone and cable (perhaps 40 feet).
* There is pex for plumbing in the addition. (ie: no metal pipe)
* We are replacing the phone and cable feeds because we have line noise in both our phone and cable. The working theory of both the phone and cable techs is that the lines are getting interference from the power cable in the trench from the road. All 3 cables are buried very close together in a 60 foot trench. When I tested a new cable into our basement instead of to the old demarc point, the noise was gone and the signal strength was much better.
* I plan on using insulated #6 copper for the wire that bonds the rods
* The rods will probably be 30 or 40 feet apart.
* A sidewalk and driveway get in the way of burying the bonding wire

 

[mpoulton]

I don't know any reason why a supplemental grounding electrode couldn't be bonded to a subpanel's grounding bus.

 

[AllanJ]

A subpanel in the same building as its feeding panel does not need a ground rod but does need a ground wire (equipment grounding conductor) in its feed.

The grounding electrode conductor does not have to be buried but needs to be protected from physical damage.

 

[k_buz]

Why install a ground rod at the sub panel? All you have to do is run a #6 to a inter system bonding bridge from the ground bar of the sub.

 

[AllanJ]

I would be tempted to epoxy a ground wire across a driveway or sidewalk although I need to look up in the NEC to double check if this is adequate protection. There is the disadvantage that the mini-berm produced may result in rain water seeping under the garage door instead of running off down to the street.

 

[mpoulton]

I understood his post to mean that he's installing the supplemental electrode at the subpanel because that's where his phone and cable service comes in, and those need a nearby rod for lightning protection. Of course, that rod must also be bonded to the system. You wouldn't want to run the phone/cable grounding conductor all the way around the house to reach the main grounding electrodes - that long of a grounding path would be pretty useless for lightning protection.

 

[stickboy1375]

Just so the OP is VERY clear on what must be done to meet code on what he suggests.

Even though the graphic uses CATV as an example, this goes for phone systems as well.

 

[stickboy1375]

Why install a ground rod at the sub panel? All you have to do is run a #6 to a inter system bonding bridge from the ground bar of the sub.

That wouldn't meet code..

 

[ctblue]

Thanks to you all for taking the time to answer my question. With your answers and with some extra Internet research (that your answers triggered), I have decided to use the 6 AWG to bond a new ground rod to the old ground rod. I'll then ground my phone and cable to this new rod before having them enter the building. I found that the gap between the driveway and the garage slab should be wide enough to dig down a few inches to bury the wire (and I'll tunnel under the sidewalk). That way, I won't have the ground wire exposed to accidental cuts along the side of my house. With a few hundred dollars in materials and a lot of shoveling, I'll feel confident that everything is grounded properly. Plus, I'll have a bonus of a 2nd ground rod for my house. I'll bury the bonding wire 18 inches deep whenever possible to avoid future rototillers, lawn aerators, etc. (By the way, I initially said the distance between the old and new rod would be 30 or 40 feet. I was way off. When I measured it, the distance was 80 feet. I don't think this extra distance matters much in the effectiveness of the bond between the rods, but please let me know if I'm wrong.) Thank you all again.

 

[stickboy1375]

Thanks to you all for taking the time to answer my question. With your answers and with some extra Internet research (that your answers triggered), I have decided to use the 6 AWG to bond a new ground rod to the old ground rod. I'll then ground my phone and cable to this new rod before having them enter the building. I found that the gap between the driveway and the garage slab should be wide enough to dig down a few inches to bury the wire (and I'll tunnel under the sidewalk). That way, I won't have the ground wire exposed to accidental cuts along the side of my house. With a few hundred dollars in materials and a lot of shoveling, I'll feel confident that everything is grounded properly. Plus, I'll have a bonus of a 2nd ground rod for my house. I'll bury the bonding wire 18 inches deep whenever possible to avoid future rototillers, lawn aerators, etc. (By the way, I initially said the distance between the old and new rod would be 30 or 40 feet. I was way off. When I measured it, the distance was 80 feet. I don't think this extra distance matters much in the effectiveness of the bond between the rods, but please let me know if I'm wrong.) Thank you all again.

The distance isnt an issue, the only issue is that your phone and catv are bonded to the electrical system grounding electrode system...
the graphics I posted pretty much sum up what is required for you to do.