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Unregistered
August 5th, 2004, 12:36 PM
I have read several times Warren Goodrich's article on installing a new meter/panel/grounding. And I am still not clear. I have a new 200 amp meter can with overhead service (below roof line). And a new 200 amp service panel in the basement. I am still fuzzy on the grounding of the meter box and the service panel. Here is what I am planning on doing, correct me if I am wrong. I have run a #4 copper grounding wire (which is protected by pvc ) from the meter box to a 8ft grounding rod below this. I bought a grounding lug and attatched it to the inside of the meter box. Should this ground wire be bonded inside the meter box or should it be bundled into the neutral wire on the load side of the meter? Question 2). I have driven a second grounding rod just below the site where my service wire goes (about a foot from the other grounding rod that I used to ground the meter box) inside the house. I am using pvc conduit for both the riser and below to run my 2/0 copper SE cable from the load side of the meter box into the house and into the service panel. The metal water pipe is on the other side of the house. So I plan on running a very long #4 copper ground wire from the metal water pipe ( yes it runs 10 ft continuously into the ground) where it enters the house..... running it unbroken...... to the 200 amp service panel and placing this on the neutral bar. Then I plan on running a seperate #4 copper grounding wire from my second grounding rod into the service panel and bonding this to the grounding lug attatched to the metal box or to the neutral bus bar. I am using a Square D 200 amp panel and a Milbank meter box socket. Does the #4 grounding wire need to run continuous from the second grounding rod through the service box...... connected to the neutral bus bar...... and onto the metal water pipe on the other side of the house. Or should I run from the water pipe..... then outside to the second grounding rod........ then back inside to the neutral bus bar as one continous loop. Need to get this correct before I have the inspector out to approve this. thanks in Kansas City

suemarkp
August 5th, 2004, 01:39 PM
I have run a #4 copper grounding wire (which is protected by pvc ) from the meter box to a 8ft grounding rod below this. I bought a grounding lug and attatched it to the inside of the meter box. Should this ground wire be bonded inside the meter box or should it be bundled into the neutral wire on the load side of the meter?
If the neutral meter bar has a third lug, I'd attach your ground electrode conductor there. If not, putting a separate lug in the meter box is OK as long as it makes a good connection to the box (scrape off paint under it) and the neutral bus also makes a good connection to the box (it usually does). In my area, we're not allowed to ground from the meter box, so you have to do it from the outside of metal conduits or run it from the panel instead. You can choose any place along the neutral from the weatherhead to the main panel in which to run grounding electrodes. A purist would want them all from one bus bar.


Question 2). I have driven a second grounding rod just below the site where my service wire goes (about a foot from the other grounding rod that I used to ground the meter box) inside the house. I am using pvc conduit for both the riser and below to run my 2/0 copper SE cable from the load side of the meter box into the house and into the service panel. The metal water pipe is on the other side of the house. So I plan on running a very long #4 copper ground wire from the metal water pipe ( yes it runs 10 ft continuously into the ground) where it enters the house..... running it unbroken...... to the 200 amp service panel and placing this on the neutral bar. Then I plan on running a seperate #4 copper grounding wire from my second grounding rod into the service panel and bonding this to the grounding lug attatched to the metal box or to the neutral bus bar.
This second rod doesn't seem quite right. You do two rods because one may have too much resistance. The second rod must be at least 6 feet from the first. I'd relocate this rod to be further from the first, and just bury a #6 or #4 copper wire in the ground between the two rods (an unspliced wire from neutral to last rod would be better, but its not required. Just each segment must be unspliced). I would run the long #4 to the water pipe from the combined neutral/ground bar of the 200A panel.


Does the #4 grounding wire need to run continuous from the second grounding rod through the service box...... connected to the neutral bus bar...... and onto the metal water pipe on the other side of the house. Or should I run from the water pipe..... then outside to the second grounding rod........ then back inside to the neutral bus bar as one continous loop.
Each ground electrode can have its own unspliced wire -- you don't have to do everything with one long wire (nor should you). If it is easy to get ground wires from your inside panel to the outside, I would do the following:
1. Run an unspliced #4 from the panel neutral/ground bus to the water pipe, attaching to that pipe within 5' of where it enters the house.
2. Run an unspliced #4 from the panel neutral/ground bus outside to rod 1. Run another #4 copper from rod 1 and go to rod 2. The rods must be at least 6 feet apart, preferably 8 feet or more.

Instead of connecting the second ground rod to the first, you could just run an additional unspliced wire from the panel neutral/ground bus to the second rod. This will take more wire, but is legal. Everything in the ground electrode system needs to be interconnected, and a bus bar is the best place to do this interconnecting. But you can interconnect from any electrode to another if you want to, its just normally isn't done that way except from ground rod to ground rod.

Unregistered
August 5th, 2004, 02:15 PM
The only reason I have the second grounding rod is that I thought that the meter can had to be grounded to a seperate ground rod. If the can and the neutral/ground bus bar can be hooked to the same ground rod, then the second ground rod was probably a waste of 10 bucks. One grounding rod and one metal water pipe sufficent to ground the neutral/ground in the inside service panel??

Wgoodrich
August 8th, 2004, 06:04 PM
Suemarkup worded his reply well.

You did not waste money on a second rod. The second rod augments the first rod to help ensure less than 25 ohms to ground. Much like the more the merrier so to speak.

Good Luck

Wg