Looking at a 400amp service in an old building. Stone foundation, plastic water pipe. The two rods are the only grounding means. Do the rods and #6 really suffice as a GES for this service? If not, to what section of 250 does one turn?
If the conditions are as stated regarding the presence of any possible ground electrodes, then the two rods and #6 is sufficient.
Not only that, it is also quite adequate to achieve its primary function for being there in the first place which is to provide the utility provider a functional way to not have to run a safety ground along with the circuit wiring on their service drops across the land, therefore saving them money.. All the other stated reasons in the code book for grounding are baloney and your building is proof of that.
I have never seen a house like this . No well head even ?
I would think that the rods needed a full size neutral , rather than the #6qwg
as a " Supplemental " ground point . As stupid as it sounds . To be supplemental , the rods would be in addition to another ground point , in this case , the rods are the only ground point .Even No Plate Electrode is provided.
well it's at least something to ground too. Which actually brings up another point, if where only supposed to be using the underground water pipe as a GEC and the interior piping has no bearing on the GEC then why do we have to jump the hot water heater??
Interior piping = bonding of metal objects likely to become energized to the neutral return path at the service. This part is the good part.
The equipment grounding conductor which would be better called the equipment bonding conductor, of the water heater supply, should be adequate for bonding both the hot and the cold water piping sides of the system.
You are not using the interior piping as a ground but rather you are bonding the metal pipe so that it is at the same potential as everything else in the building. If there is metal piping coming in the building then the first 5' is part of the eelctrode attached to the underground pipe. You must use the piping as an electrode. The reason to supplement the water pipe with rods or some other means is because if the underground piping gets replaced with nonmetallic pipe then you have no electrode at all.
As mentioned bonding the water pipes across the WH is for the largest circuit that may energize these pipes . I have always done this too . I just use a piece of #4 and 2 clamps out of habit . It was done so when the WH is removed to change it , you do not loose your bond . They may jump the water meters also . Pete
Pete87 , I bond like that also. #6 , two clamps, peace of mind .If you have a laundry faucet all brass it's just as good. But me , I bond them anyway.Gas or electric. In my head it's what they use called dielectric fittings on hot water tanks now.
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