Extending my ground wire

[snowman03782]

Hello all-
I have been around here for a while just looking at all the info, great site. Just now I am opening up my account to post because I have a question.

Building a 28x28 detached garage right now, a friend of mine told me that the best way to supply it with power would be from the house because having our local utility hook up another meter would cost a fortune.

I took his word for it and planned on running a feeder from my house. Trying to keep this short, I basically found out from my utility after the fact that it costs next to nothing for them to run the service drop to the meter. This will be alot easier than trying to trench in my extremely rocky soil. I dont mind that it will cost me 13 bucks a month to have it there.

Here is the issue, I installed my grounding system and wire coming up through the slab (in conduit of course) on the opposite side of where the service drop would come from

I have about 8 feet of bare 6 gauge on the opposite wall now. I dont want to run 100amp service all the way across the garage just to meet up with my ground obviously. Will code allow me to get some of those bolt clamps and extend the ground in conduit up the wall, across the overhead, and back down to the panel near the meter?????? I laid the ground rods in the trench when before the foundation was backfilled and really dont want to try and drive rods in the ground, I wasnt very successful on the first attempt.

Thanks in advance for any advice!!

 

[tfi racing]

No.You will need to rent a hydraulic crimper and get the appropriate sized crimp and press the thing together,anything that can be unbolted or screwed won't be approved.

 

[Stuart in MN]

That is correct (at least in the US, I don't know about Canada.) The grounding conductor is supposed to be continuous without splices or joints, but the NEC does have an exception that allows splices made with crimp connectors that are listed for this purpose.

 

[Stuart in MN]

An exothermic cad weld still allowed per the NEC. I didn't mention it in my earlier post as it's not the sort of thing a homeowner is equipped to do.

 

[rockwithjason]

the NEC will allow a splice in a grounding electrode conductor under specific conditions. if a mechanical splice is used it must be irreversible (you can't take it back apart) and some areas require that the device be listed for the purpose. you can also use exothermic welding commonly called cadweld. this process uses a chemical process to melt a welding material onto the conductors to be spliced and welds them together. you can run bare copper from the location to the new service as long as there is no contact with anything that will corrode the copper. running grounding electrode conductors in metal conduit requires that the conduit be bonded to the conductor on both ends of the run and that the conduit be directly bonded to the rod. in your case i would consider digging a 30" deep trench and burying the rod horizontally and cadwelding the conductor to it. then you could extend the conductor to the service. check with the local inspectors and the utility to be sure they will allow this. if that is not an option i would run #6 bare solid copper from the old location to the new on and get a one shot cadweld for the connection to the original conductor.

 

[snowman03782]

Thanks for the quick replies fellas. It occurred to me, I do have a piece of rebar sticking up through the frostwall that I asked the cement contractor to put in to use as a bonded electrode. There are two issues with that though. One, I think he forgot to put it in before they started pouring. I am very suspect that he just shoved a 4 foot or so piece in the fresh cement and told me later it was all set. I say this because I was looking it over the day after the pour and it moves around quite easily and just doesnt feel like theres 20 feet of rebar there. Also, its a 3/8" piece of rebar, not the required 1/2".

This rebar is right next to my conduit (same place basically). What I am thinking is I could get the correct rebar/gnd wire clamps and then run a long #6 up, over, and down to the panel. In addition to this, I could also clamp my existing ground wire which is connected to two 8 foot gnd rods, to the rebar as well. If the inspector asks me what thats all about, I would explain that I realized the rebar was undersized per the NEC spec and I added the ground bars to supplement. Think that would work???

Do I need to run the wire up, over, and down in conduit????

I have seen the clamps at the big box stores that are intended to clamp the ground wire to the rebar. The bolts on these are hex head making it reversible.... whats that all about? Thanks again...

Thanks again-

 

[hillbilly1]

I have seen the clamps at the big box stores that are intended to clamp the ground wire to the rebar. The bolts on these are hex head making it reversible.... whats that all about? Thanks again...

Thanks again-

The irreversible connection applies only to the grounding electrode conductor, not the to grounding electrode its self.

 

[snowman03782]

Nice, so with that being said, I can probably get away with the clamp for the wire/rebar connection to go up, over, and down, while I also clamp my wire to the 3/8' rebar. I dont trust what the foundation contractor did, I do know that I laid the appropriate stuff down before backfilling though.

Conduit needed to run across the garage with the ground?

 

[Charles (in GA)]

If you are using the solid copper bare ground wire, it really doesn't need to be in a conduit, you could if you wanted, it won't hurt and you can placard it as to what it is for future owners.

You cannot have any splices in the WIRE except the NON-reversible ones as mentioned earlier. You can get one shot exothermic weld kits at some electrical supply houses if you need to splice the wire.

Charles

 

[snowman03782]

The 6ga I have right now coming out of the slab is bare stranded......

 

[scuba0459]

Why would you not just install a new ground rod in a more convenient location. They are not too expensive and unless you hit a boulder on the way down the job should not be to hard to do.

I'm actually asking you this because I need to install my ground rod in the next couple of days.

Albert

 

[snowman03782]

I am not sure how rocky it is in Alberta, but I am in New Hampshire "The Granite State". The foundation contractor almost wasnt able to excavate with his machine... so in short, it would be a complete pain the the rear! There were alot of rocks almost 12" in dia, many were double that, a few over 3 feet. My local code also calls for two ground rods = double the trouble.

I laid mine down horizontally before backfilling, about 14 feet apart too. I read that you should add salt to aid the conductivity and I did this as well (softener salt was nearby).

 

[scuba0459]

Years ago the glaciers came and piled all the rocks along the western border of the province and made the rocky mountains. So for us here their are some good sized rocks in the ground but hitting them with the ground rod is more like bad luck than a normal occurrence. I read in the electrical code book about laying the ground rod on it's side but I could never figure out why. Now I understand.

Have a great weekend.

Albert

 

[snowman03782]

I think I heard of them there mountains out your way! Good wknd to you all too.

 

[tfi racing]

Why would you not just install a new ground rod in a more convenient location. They are not too expensive and unless you hit a boulder on the way down the job should not be to hard to do.
I'm actually asking you this because I need to install my ground rod in the next couple of days.
Albert

Ground rod?Before you go crazy trying to pound one into the frozen tundra,check the CEC.Detached structures subfed from the main service usually don't require a separate ground electrode in Canada,and if so,the majority of electricians in Alberta use a ground plate instead.