kwired
Electron manager
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- NE Nebraska
Could have (likely was) just capacitive coupling creating this voltage. You will have more problems with degrading of the line from DC current and electrolysis than you will have from AC current.
bonding copper water pipe
- Thread starter novemberaudi
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Could have (likely was) just capacitive coupling creating this voltage. You will have more problems with degrading of the line from DC current and electrolysis than you will have from AC current.
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That may be the least of your problems. The water pipes were not grounded in my house when I moved in. I took care of it in the first year after taking up residence fifteen years ago.
You should see how much hair I have lost and how much weight I have gained since then.
I agree with this. Even with the DMM leads in free air, they will read between 50 and 100mV AC. As for DC, I checked across the hot and cold at the water heater before bonding and no DC voltage. However, where is the DC referenced to is the question. Or is it the DC portion of an AC circuit (yes, even an AC has a little DC voltage)
kwired
Electron manager
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AC service alone, probably not much for DC current sources, sure there could be some DC component in the AC service.
Most DC problems come from either telephone lines, or other separately derived DC systems. You need to find those sources and find out if your water piping has become a part of a path for those systems.
jxofaltrds
Inspector Mike®
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New I had it somewhere.
jxofaltrds
Inspector Mike®
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Knew. LOL
kwired
Electron manager
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- NE Nebraska
Depending on if there are other electrodes of any kind, it may be a bonding jumper to both rods.
Your point???
John120/240
Senior Member
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I think that jxofaltrds was trying to emphasize that the graphic calls it a bonding jumper.
jxofaltrds
Inspector Mike®
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That and a #6 AWG is the largest required when just using a rod. One, two or a hundred.
Now if you connect the 10' underground metal water line to the ground rod then things change.
Counterpoint is the depiction does not exemplify that. The service conductors could be 1/0 CU or 3/0 AL, or smaller.
jxofaltrds
Inspector Mike®
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250.66 Size of Alternating-Current Grounding Electrode
Conductor.
(A) Connections to Rod, Pipe, or Plate Electrodes.
Where the grounding electrode conductor is connected to rod, pipe, or plate electrodes as permitted in 250.52(A)(5)
or (A)(7), that portion of the conductor that is the sole connection to the grounding electrode shall not be required to be larger than 6 AWG copper wire or 4 AWG aluminum wire.
250.66 Note: Aluminum cannot be connected to an 8? ground rod.
...and I remind you of the part I [additionally] emphasized...
kwired
Electron manager
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- NE Nebraska
Where did he mention connecting aluminum to the ground rod? His counterpoint mentions the depiction does not clarify a situation where 250.66 would otherwise require a GEC to be larger than 6AWG copper. The mentioned aluminum was the service conductor not the GEC.
jxofaltrds
Inspector Mike®
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Sole connection or not?
http://www.electricalnews.com/bridgeport-introduces-intersystem-ground-rod-bridge-clamp/
kwired
Electron manager
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Maybe, might depend on if the multiple terminations are used, and what they go to.
I still am not convinced either way that a 6 AWG to one rod - then continuing on to another rod is considered a single or multiple electrodes, and will say I have done it many times where a larger than #6 would be required if considered multiple electrodes.
The clamp is not what determines whether there is a sole connection or not.
jxofaltrds
Inspector Mike®
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Nice read:
http://www.iaei.org/blogpost/929497/170572/Sole-Connections?hhSearchTerms="ground+and+rod"&terms=
"Question: At 250.66(A) and (B), the Code refers to a "sole connection to the grounding electrode.? Please explain what sole connection means; and is the term sole connection defined anywhere in the NEC? PM"
....... "The plural language and revised text at both 250.66(A) and (B) should make it clear that the Code considers these two ground rods to be one electrode as far as the sole connection sizing provisions are concerned, and 6 AWG copper conductor could be used at both ground rods."
http://www.iaei.org/blogpost/929497/170572/Sole-Connections?hhSearchTerms="ground+and+rod"&terms=
"Question: At 250.66(A) and (B), the Code refers to a "sole connection to the grounding electrode.? Please explain what sole connection means; and is the term sole connection defined anywhere in the NEC? PM"
....... "The plural language and revised text at both 250.66(A) and (B) should make it clear that the Code considers these two ground rods to be one electrode as far as the sole connection sizing provisions are concerned, and 6 AWG copper conductor could be used at both ground rods."
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