Ground Rod

[Russell]

I am building a woodworking shop with new service. (Meter base, 200 A service and all new circuts). My question is about the ground rod. Shop is on a slab with a foundation that extends about 8-10 inches from the edge of the slab. I hate to put the ground rod that far from the building (hit with mower or other damage). Can I just bend the rod with an offset to get it closer to the building and then cover the offset portion with dirt (with clamp above ground of course) or is there another option I should consider?

Also I put plastic conduit from the bottom plate of the wall under the slab for my tablesaw in the middle of the floor and was wondering if I needed to run conduit all the way to the service panel or if I can run cable from the service panel to the bottom plate where the conduit begins. ( If so do I need a cable clamp of some type at the conduit?)

Thanks for any input!! :D :D

[bkrahmer]

I don't have an opinion on your ground rod issue. However, I will say that romex cannot be left exposed. If you will be covering the wall cavity, I don't see why you couldn't run down to the plate without conduit. If you aren't covering it, you'll need to continue the conduit to the panel.

[Russell]

Thanks for the info, I will be sheetrocking the walls so it will be covered.

Russell

[Rich]

You can put your ground rod into a landscaping box. It's essentially below grade yet covered with a durable cover.

[Russell]

Thanks Rich, I hadn't thought of that. Do you mean a box like you use for underground sprinklers and such or is there a specific electrical box? If so what do I ask for at the electrical supply store?

Thanks again :D

[Rich]

Not sure if there is a specific electrical box.. I've just seen regular sprinkler / landscaping boxes used before.

[kadoka]

Russell

Code around here is that the ground rod needs about 6' from the eave. Just bury the rod a foot in the ground and run your wire underground to the building. You won't hit the rod with your mower that way. I think it is supposed to out from under the eave so the ground it is in doesn't dry out too much and reduce the electrical connection between the rod and the ground.

[Sparks]

What I would do is simply drive the rod further into the earth. 4 inches or so and use a listed acorn clamp and run your #4 or #6 wire in a small shallow trench to the building. If you're still concerned, when the wire leaves the earth you can run it through pvc, (to protect it) don't use steel conduit as it will need to be bonded properly at both ends. Richs idea would also work, you could just get a NEMA 3R pvc box and enclose evrything if you like. Either way is fine.

[Sparks]

Just make sure your acorn ground clamp is listed for direct burial, most are. And your romex is fine as described, just put a fitting (female) or use the bell end where your romex enters. No special fitting needed. Just support the romex properly and don't expose it to damage. Also, you may already know this but make sure to run a 4 wire feeder to your new shop (unless this is your main service) and separate the neutral from the ground. In other words, don't insert the green bonding screw, throw it away and keep you neutrals and grounds separated in the panel.

[Russell]

Sparks

This is a new service direct from the city pole to a new meter on the shop (Totally separate from my house service). So, do I need a 4 wire service to this set-up. If so what is the 4th wire for? I know there are 2 110v and 1 Neutral but what is the 4th wire for and where does it go? Sorry for the stupidity but I want to get this right.

[bkrahmer]

Disregard the following parts of Sparks' last post. He was thinking you had a subpanel, not a panel. :)

Also, you may already know this but make sure to run a 4 wire feeder to your new shop (unless this is your main service) and separate the neutral from the ground. In other words, don't insert the green bonding screw, throw it away and keep you neutrals and grounds separated in the panel.

[Sparks]

Well, I did throw in "unless this is your service" to avoid any miscommunications. Obviously then, this is a separate service, so no a 4 wire feed is not allowed. 3 wire then of course bond the panel, meaning install the green bonding screw and install 2 ground rods, not one, unless you have the equipment to prove 25 ohms or less to earth which generally it's much more than that even with 2. So you'll need 2 rods with one continuous wire connecting them together. Also, be sure to bond any metal piping, gas, water, etc,. If you're running a metal water pipe to the workshop, you could use this as your grounding electrode and then supplement with one ground rod. And also, don't do what you said in your first post (bending the rod) the way you decribed sounded like the rod would only be partially driven and then bent over, can't do that. And, with a 200a service, just run #4 to the rods, nec only requires #6 but some areas and utilities require #4 for a 200a service and they'll enforce it. Of course you could check with your local authority as well.

[Sparks]

I don't know your location but some areas have some strange requirements on grounding. In my area of NY, we are required for one to use #4 for a 200amp service (#4 wire to rods) and then we are also required to come out of the panel with wire, go to first rod, continue to 2ND rod and go BACK INTO PANEL. All with one continous wire, unbroken. Check to see if your utility has a web site and sometimes they have detailed specs on what they want or just call the inspector and have a conversation on what he will require, make the inspector a friend, not a foe :)

[porcupine]

Russell,
If you have no water main available, you need 2 rods. Get a hammerdrill with a 3/4" bit, drill 2 holes, 6 feet apart, (and next to your exterior wall), through the slab, insert the (2) 5/8"d. ground rods, and drive them in. Problem solved.
HINT: Drop the acorns down the rod BEFORE you start driving them into the ground. Because, unless you live in a rock free area, you are more than likely to mushroom the end of rod during the "driving-in" process. Then you will have a hell of a time getting the acorns on.
Good Luck

[porcupine]

Russell,
If you have no water main available, you need 2 rods. Get a hammerdrill with a 3/4" bit, drill 2 holes, 6 feet apart, (and next to your exterior wall), through the slab, insert the (2) 5/8"d. ground rods, and drive them in. Problem solved.
HINT: Drop the acorns down the rod BEFORE you start driving them into the ground. Because, unless you live in a rock free area, you are more than likely to mushroom the end of rod during the "driving-in" process. Then you will have a hell of a time getting the acorns on.
Good Luck

[Sparks]

Outside or in, makes no difference. If the building was mine, I would have them outside. The utility in my area requires grounding electrode conductor buried in a shallow trench eliminating hitting them with mowers and the like from being a problem anyway. And I'll second putting the acorn on prior to pounding the rod, around here the rods mushroom pretty bad by the time they're sunk. Have you ever come across part of a ground rod cut with a sawzall laying in the bushes? This guy forgot to install acorn first :x

[Russell]

Thanks for the great info!! I think I will go with the trench method and probably put 2 rods in (Code here calls for 1 but I'm one of the overkill kind of guys) Sorry about the delay in responses but we have been replacing tar paper (50 mph winds do a lot of damage) and shingling the past 2 days. Thanks again for the information. :D :D