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Old 08-13-2012, 10:26 PM   #31
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Need Help Understanding Neutal / Ground


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Originally Posted by gookinp07 View Post
The power is brought to the home from overhead. There is a 110v line going to a light on a pole next to the pier. The light is operational. Other than that, there was a VHF antenna cable buried underground, but it was severed a couple decades ago. I have no idea if it's still there, but it definitely isn't operational.
Ok I'm not seeing any red lights. Just wanting to make sure there is not another path that could be energized out to the pier.

This might be hard to visualize but it would appear that your ground wiring is energized and it doesn't appear to be from your wiring. Hard to tell I'm not there ...

Any homes close to yours ? Do you have under ground metal (copper or galvanized ) water pipes with the homes served from a common metal main water line?

Heres my best stab at your problem your earth grounding system (ground rods, metal water pipes ) is allowing the energizing of the egc in your wiring to the dock due to a voltage gradient in the earth (some external electrical source).

Or its in the water and you see the spark coming from the ladder to your cable because your cable is completing a circuit with your ground wire and transformer.

1.5 volts is very low voltage

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Old 08-13-2012, 10:30 PM   #32
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Need Help Understanding Neutal / Ground


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Ok I'm not seeing any red lights. Just wanting to make sure there is not another path that could be energized out to the pier.

This might be hard to visualize but it would appear that your ground wiring is energized and it doesn't appear to be from your wiring. Hard to tell I'm not there ...

Any homes close to yours ? Do you have under ground metal (copper or galvanized ) water pipes with the homes served from a common metal main water line?

Heres my best stab at your problem your earth grounding system (ground rods, metal water pipes ) is allowing the energizing of the egc in your wiring to the dock due to a voltage gradient in the earth (some external electrical source).

Or its in the water and you see the spark coming from the ladder to your cable because your cable is completing a circuit with your ground wire and transformer.

1.5 volts is very low voltage

The 1.5 could be voltage drop on the primary neutral, if this is the case that 1.5 volts will rise and fall with load demand during the day...
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Old 08-13-2012, 10:31 PM   #33
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Need Help Understanding Neutal / Ground


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Do you understand how and why the hair dryer did not trip the GFCI?
No. (Evidently you can't just submit "No."... you need 5 characters)
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Old 08-13-2012, 10:34 PM   #34
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Need Help Understanding Neutal / Ground


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The 1.5 could be voltage drop on the primary neutral, if this is the case that 1.5 volts will rise and fall with load demand during the day...
HMMMM I hadn't given that any thought might just be correct.
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Old 08-13-2012, 10:35 PM   #35
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No. (Evidently you can't just submit "No."... you need 5 characters)

The reason the GFCI did not trip was simple, there was no alternative place for the current to return to the source from, so the GFCI did not detect a imbalance and never tripped, this is acceptable... had you stuck your hand in the bucket or whichever body of water, the current would have an alternative path back to the source and would have tripped the GFCI device....

GFCI's measure current IN and current OUT.. Until they have a secondary path back to the source, they stay energized.

Last edited by stickboy1375; 08-13-2012 at 10:39 PM.
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Old 08-13-2012, 10:36 PM   #36
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Need Help Understanding Neutal / Ground


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Ok I'm not seeing any red lights. Just wanting to make sure there is not another path that could be energized out to the pier.

This might be hard to visualize but it would appear that your ground wiring is energized and it doesn't appear to be from your wiring. Hard to tell I'm not there ...

Any homes close to yours ? Do you have under ground metal (copper or galvanized ) water pipes with the homes served from a common metal main water line?

Heres my best stab at your problem your earth grounding system (ground rods, metal water pipes ) is allowing the energizing of the egc in your wiring to the dock due to a voltage gradient in the earth (some external electrical source).

Or its in the water and you see the spark coming from the ladder to your cable because your cable is completing a circuit with your ground wire and transformer.

1.5 volts is very low voltage
I am in a neighborhood, but the next closest home is probably 150 feet away from my house and probably 300 feet from my pier. My house uses well water which is fed to the house with plastic water line. There is old copper plumbing in the house, but I don't believe it goes underground. I have a basement with a conrcete floor. However, now that I think about it, I believe there is a large iron pipe for sewage that goes underground.
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Old 08-13-2012, 10:38 PM   #37
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Need Help Understanding Neutal / Ground


Although these are interesting cases, they are VERY hard to diagnose this way, without actual testing and repeat testing and visuals...
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Old 08-13-2012, 10:39 PM   #38
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The reason the GFCI did not trip was simple, there was no alternative place for the current to return to the source from, so the GFCI did not detect a imbalance and never tripped, this is acceptable... had you stuck your hand in the bucket or whichever body of water, the current would have an alternative path back to the source and would have tripped the GFCI device....

GFCI's measure current IN and current OUT..
Gotcha, that makes sense. It's been a while since I've seen it, but now that I think about it, I think they may have made a modification to the setup to make it work. They may have grounded the metal drain in the tub.
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Old 08-13-2012, 10:41 PM   #39
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Gotcha, that makes sense. It's been a while since I've seen it, but now that I think about it, I think they may have made a modification to the setup to make it work. They may have grounded the metal drain in the tub.
Exactly, in todays plumbing world, everything is plastic... but people think GFCI's should still trip, which of course they won't....
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Old 08-13-2012, 10:43 PM   #40
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Need Help Understanding Neutal / Ground


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I am in a neighborhood, but the next closest home is probably 150 feet away from my house and probably 300 feet from my pier. My house uses well water which is fed to the house with plastic water line. There is old copper plumbing in the house, but I don't believe it goes underground. I have a basement with a conrcete floor. However, now that I think about it, I believe there is a large iron pipe for sewage that goes underground.
I beleive you read JBFANS reply to your other thread it would be better to be on that other thread with our posts but too late I think. Anyway you might have the owners turn the power off to any docks close to yours and see what happens.

I have to confess though you may be a lot smarter to get an electrician involved.
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Old 08-13-2012, 10:44 PM   #41
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I beleive you read JBFANS reply to your other thread it would be better to be on that other thread with our posts but too late I think. Anyway you might have the owners turn the power off to any docks close to yours and see what happens.

I have to confess though you may be a lot smarter to get an electrician involved.
And the power company, they can turn off circuits a lot easier.
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Old 08-13-2012, 10:47 PM   #42
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Although these are interesting cases, they are VERY hard to diagnose this way, without actual testing and repeat testing and visuals...
Gotcha, I understand that it's difficult and I really appreciate the help you guys have been giving me. I'm going to have the POCO come out ASAP and do whatever testing they need to do. If it ends up being a problem on my end, I'll just get an electrician to look at it. With all of this talk about "voltage gradients", it sounds like I'm getting in over my head pretty quickly. I was just hoping it would be something relatively simple.
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Old 08-13-2012, 10:47 PM   #43
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1.5 volts is very low voltage
I know this sounds low, but in a pool i bet you would feel this, 4 volts is extremely painful. Maybe odd fully painfull, not screaming painfully, but can still cause people to freak out and drown.

Last edited by stickboy1375; 08-13-2012 at 10:49 PM.
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Old 08-13-2012, 10:47 PM   #44
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And the power company, they can turn off circuits a lot easier.
That's true ...
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Old 08-13-2012, 10:50 PM   #45
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I know this sounds low, but in a pool i bet you would feel this, 4 volts is extremely painful.
No I didn't mean that 1.5 volts is not something to worry about I just meant it was lower than I would have expected but even 1.5 volts will tingle you.

Need to explore his testing method but even so I think he meeds to cut his losses and get experienced help.

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