timselectric
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It really does depend on the equipment and installation circumstances.
Last check for ground plan of my offgrid system
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garetwo
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I think if I ever become acquainted with more inverters, I will see this is true. Also, it has not gone unnoticed that you brought it back to the original statement. I will not succumb to the desire to create a perpetual loop.
Thank you but first I am trying to figure out the proper grounding in my situation.
garetwo
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You write as though you started this thread!
garetwo
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We must land it on the utility side of the supply water disconnect AND drive one ground rod 8' deep (so a ten ft rod or a ground well with an 8' rod) near this, AND one more, greater than 6' away, AND bond them together...well that was San Francisco some years ago.
However, I do find it interesting you can just have a landing on a cold-water pipe because those may get disconnected with repairs, additions, modifications.
What is a ground loop please? A ground grid is often specified by some engineers where multiple ground rods are driven and a confirmed less than 25-ohm resistance to ground must be made AND they get bonded together. I would love to know the reasoning behind it, but it may get this thread going elsewhere
.Then, there are those places with no apparent grounding and there is a measured potential between some potential current carrying parts to earth ground.... I assume because the utility has grounded their secondary and now a potential can exist.
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I cannot explain this well but according to WillWe must land it on the utility side of the supply water disconnect AND drive one ground rod 8' deep (so a ten ft rod or a ground well with an 8' rod) near this, AND one more, greater than 6' away, AND bond them together...well that was San Francisco some years ago.
However, I do find it interesting you can just have a landing on a cold-water pipe because those may get disconnected with repairs, additions, modifications.
What is a ground loop please? A ground grid is often specified by some engineers where multiple ground rods are driven and a confirmed less than 25-ohm resistance to ground must be made AND they get bonded together. I would love to know the reasoning behind it, but it may get this thread going elsewhere
Then, there are those places with no apparent grounding and there is a measured potential between some potential current carrying parts to earth ground.... I assume because the utility has grounded their secondary and now a potential can exist.
Hello garetwo I heard in a video from Will Prowse that putting 2 rods in the ground could create a ground loiop. Sorry this is over my head and I dont want to explain incorectly.We must land it on the utility side of the supply water disconnect AND drive one ground rod 8' deep (so a ten ft rod or a ground well with an 8' rod) near this, AND one more, greater than 6' away, AND bond them together...well that was San Francisco some years ago.
However, I do find it interesting you can just have a landing on a cold-water pipe because those may get disconnected with repairs, additions, modifications.
What is a ground loop please? A ground grid is often specified by some engineers where multiple ground rods are driven and a confirmed less than 25-ohm resistance to ground must be made AND they get bonded together. I would love to know the reasoning behind it, but it may get this thread going elsewhere
Then, there are those places with no apparent grounding and there is a measured potential between some potential current carrying parts to earth ground.... I assume because the utility has grounded their secondary and now a potential can exist.
timselectric
If I can do it, you can do it.
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That's when the two rods have some distance between them. And separate connections to the grounding system. It takes two connections to make a loop.
We place them close together (usually 10' or less) and make a single connection to them for a better connection to the earth.
garetwo
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We are in the same boat!
garetwo
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I could see that with two separate connections, though I need to find out what a loop causes. The two in SF had to have one continuous #6 bare copper. We would drive one near the shutoff for water, one near the meter/main disconnect, then run one #6 from the meter/main ground/neutral bus, to the first rod, to the second rod, to the utility side of the water shutoff.
I will look for if they still mandate this in their SF code addendum.
garetwo
New Member
They do still require it IF you cannot prove the one grounding electrode has less than 25ohms to ground and you do not get to prove it, you must hire a certified tester, although on one forum they said you can buy the ground resistance tester and do it yourself, I am not sure of that yet. Evidently a few places do it, maybe several, there was a guy from NJ said they started having to do it in the 90's, another guy in Minnesota. I did not have to do it here in Placer County Calif.
garetwo
New Member
I see that, and I found it online. I wonder if making us bond it to the water line caused one?...it was so long ago, maybe 200 years now, maybe it was the gas line and we could not bond the cold water line, to hot water line, to gas line at the water heater like everywhere else.
timselectric
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Yes, if there is another connection to the water line.
No, if not.
garetwo i suggest follow closely what timselectric says. He knows a ton more than me! lol
To add to the confusion ( I Hope not!) My house has a 18 mm insulated ground wire going from my main panel to a clamp on a water pipe outside. I measured 4 homs from that waterpipe to the water pipe near the meter on the street. So I think I have a good earth conection. However, according to Tim`s comment 20 minutes ago, If I ground my panels, inverter, sub panel, battery rack to the same ground point on my waterline then I am not creating a loop so it is all good. Sorry for beating a dead horse here but doing that make me wonder maybe I should not shower when there is a storm around.... Logic tells me to stake a rod away from the house and ground the pannels, array, battery to that. I am asking local electricians here....I get "ìt depends" or " I think it is better to use the same ground since the growatt SPF 5000 has an AC INPUT from the main panel. I don't want to learn the hard way specifically if it is the very last thing I learn!
timselectric
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It's never a good idea to shower during a lightning storm.
Has nothing to do with the ground connection.
The gradient pulse can travel through the water itself.
Has nothing to do with the ground connection.
The gradient pulse can travel through the water itself.
garetwo
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A short circuit does not want to go to ground, it wants to get back to its point of origin, I believe only lightning "wants" to go back to ground, where it came from.
Grounding one conductor stabilizes voltages, stops a floating ground for your power, or potential voltage differentials to exist that could find a path through a person. Since the ground rod is bonded to the "neutral" wire, that is where a fault wants to go. So, the further from the home, the more resistance and the tougher it is to complete a fault and trip a breaker... I think.
garetwo
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ouch! We rarely have lightning but the next time we do, I will make sure all in the home are not in the shower...same with a bathtub?
timselectric
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Not as much of a Hazzard. But still would advise against it.
Totally agree with you. But here in Aruba, I check some friends panel and nobody bound ground and neutral. An electrician who works for the utility company said that the bonding is done at the utility company. So to test that i checked resistance between neutral and ground. I got 44K.
Between L1,2 ,or 3 to ground I get 127V. So the bonding is done at utility company. Am I doing this right? Thank you.
timselectric
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Yes, I would expect your bonding to be done by the utility company.
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