kingsmurf

[won4thewoad]

perhaps a fresh set of brains can suggest a cure for the following querky problem

rural home . . .pool next to home . . . .X-former 50 feet away from home . . .SE drop to home

Problem:...current felt at pool edge when on the wet concrete edge

reseached thus far: . .everything . . .and still current shock on an low
order at pool

Querker: . . .finally removed SE connductors from mains . . ungrounded
and grounded conductors swinging in the cool air and
STILL getting low order shock at pool

Question : considering there is now nothing from POCO connected . .
and next closest POCO service is quite a ways off . .home
served by well and septic tank/leech field


? is there any possibilty that the current is from an natural
phenomenon? . .or a now present current due to an
galavanic reaction under ground?


with meter popped...and neutral open . .cannot be anything
POCO related now . .but WhollyJumpin'JesusPalimino . .I am at
an loss to explain this

any suggestions? . . .( keeping in mind that with all contact severed with POCO . .we still have current in the pool . . .no other service even
remotly close to this home )

 

[Mike Burch]

I remember a story that an inspector told me once about a similar problem he helped troubleshoot in a car repair garage. The mechanics would get a periodic low level shock while doing routine tasks around the shop. It turned out to be a corroded piece of emt along with damaged conductors within the concrete floor. After the run was replaced the problem disappeared. Concrete is pretty conductive.

 

[chris kennedy]

with meter popped...and neutral open . .cannot be anything
POCO related now . .but WhollyJumpin'JesusPalimino . .I am at
an loss to explain this

any suggestions?

Welcome to the Forum.

Search stray current.

 

[won4thewoad]

kingsmurf

Roger on the stray current . . . .but with the POCO's SE conductors swinging in the freeair . .and nada other close by (1/2 mile service for POCO )
we are at an loss for where to search

 

[don_resqcapt19]

Is there current on the grounding electrode conductor on the utility pole? The utility primary grounded conductor is connected to earth at least once every 1200' and that places the earth in parallel with the grounded conductor. They also connect the primary and secondary grounded conductors to each other and in many cases they use a single conductor for both.
Does the pool have the code required bonding?

 

[won4thewoad]

kingsmurf

roger the only possible simple explanation must be the grounding electrode
from POCO's pole/X-trans . . . BUT...with the SE conducctors swinging in the free air


bonding is irrelevant . .and we must be feeling the outer reach of the current from RADIATING outward from the pole

does that seem feasible?

POCO s coming to investigate

 

[mdshunk]

Your solution may the the Ronk Blocker. It's worked well for many dairymen in my area.

 

[won4thewoad]

kingsmurf

MDSHUNK . . .that is an greatly appreciated suggestion . .I will get that link to the folks

 

[don_resqcapt19]

bonding is irrelevant . .and we must be feeling the outer reach of the current from RADIATING outward from the pole

While bonding does not remove the problem, it can in many cases remove the touch potential around the pool and eliminate that tingling feeling.

 

[won4thewoad]

kingsmurf

Roger that Don . . .bonding is going to get addressed as well to the limit the home owner has wallet thickness...matched with the desire to do this retro on existing inground

querker this'n . . .cant wait to hear what the POCO found

 

[charlie]

. . .cant wait to hear what the POCO found

Unless they send out the best trained in stray current (stray voltage is the result of stray current), they will find nothing. If the pool was installed with a (current) Code compliant equipotential plane, this would not be a problem.

The serving electric utility can't stop the stray current (see Don's first response). If there is a grounding problem or open neutral somewhere, the current can be mitigated but not stopped. :smile:

 

[gar]

080521-1025 EST

won4thewoad:

Where are the two closest power company poles with neutral to earth ground rods. Probably these would be to the right and left of the home.

With all the service lines open including neutral, connect a long wire, 200 ft or more, to the home ground rod. Connect your voltmeter between the end of the wire coming from the ground rod and a probe for mapping the electric field. I used the Fluke meter probe.

In my yard I have an adjacent neighbor that shares a transformer with me. Fairly certain our pole has a floating delta on the primary, and any other neighbors are serviced from the same delta, but different transformers. There is a ground rod at the pole. In the house the service neutral is connected to a 1" copper water supply line that runs about 150 ft to the street.

I used an outdoor outlet to connect to the house system ground. Using an extension and a Fluke 27 I made measurements relative to the house ground. The voltage at the pole ground rod was about 35 millivolts, and at the conduit going into the house about 35 millivolts. This is at the side of the house and about 30 ft from pole to meter, and about 75 ft of 0000 copper. My 35 millivolt levels are probably from equipment line filters.

Going toward the rear of the yard about 60 ft the voltage increases to about 80 millivolts. Swing toward the opposite side of the yard it increases further to about 180 millivolts. Thus, there are currents from the neighbors.

At the shop we also have a floating delta source. So I do not have a convenient place to experiment with a primary Y where its Y neutral is connected to the pole ground rod.

The extension cord was my long wire and I just used the meter probe to measure ground potential.

Next I put a ground rod about 6" into the soil at the 75 ft point. Applied 120 V to this rod. Current was about 0.3 A. The soil is quite dry and I was not deep. Between the rod and a distance about 2 ft away was a drop of 110 V. Not a good experiment today to try to show the gradient because the drop from the house to 73 ft was only 10 V.

In any event I think the meter probe is probably sufficient for quick experiments. Whatever you do be careful because you may encounter some moderate voltages.

With this type of experiment you can field map your area of concern.

.

 

[charlie]

. . . Fairly certain our pole has a floating delta on the primary, and any other neighbors are serviced from the same delta, but different transformers . . .

I can't imagine that you are on a delta primary system because the transformers are more expensive and the "standard" US configuration is wye. :-?

 

[won4thewoad]

080521-1025 EST

won4thewoad:

Where are the two closest power company poles with neutral to earth ground rods. Probably these would be to the right and left of the home.

With all the service lines open including neutral, connect a long wire, 200 ft or more, to the home ground rod. Connect your voltmeter between the end of the wire coming from the ground rod and a probe for mapping the electric field. I used the Fluke meter probe.

In my yard I have an adjacent neighbor that shares a transformer with me. Fairly certain our pole has a floating delta on the primary, and any other neighbors are serviced from the same delta, but different transformers. There is a ground rod at the pole. In the house the service neutral is connected to a 1" copper water supply line that runs about 150 ft to the street.

I used an outdoor outlet to connect to the house system ground. Using an extension and a Fluke 27 I made measurements relative to the house ground. The voltage at the pole ground rod was about 35 millivolts, and at the conduit going into the house about 35 millivolts. This is at the side of the house and about 30 ft from pole to meter, and about 75 ft of 0000 copper. My 35 millivolt levels are probably from equipment line filters.

Going toward the rear of the yard about 60 ft the voltage increases to about 80 millivolts. Swing toward the opposite side of the yard it increases further to about 180 millivolts. Thus, there are currents from the neighbors.

At the shop we also have a floating delta source. So I do not have a convenient place to experiment with a primary Y where its Y neutral is connected to the pole ground rod.

The extension cord was my long wire and I just used the meter probe to measure ground potential.

Next I put a ground rod about 6" into the soil at the 75 ft point. Applied 120 V to this rod. Current was about 0.3 A. The soil is quite dry and I was not deep. Between the rod and a distance about 2 ft away was a drop of 110 V. Not a good experiment today to try to show the gradient because the drop from the house to 73 ft was only 10 V.

In any event I think the meter probe is probably sufficient for quick experiments. Whatever you do be careful because you may encounter some moderate voltages.

With this type of experiment you can field map your area of concern.

.

Thanks Gar I am on that page with you . .I think we know where the problem lies...and are working to that end . . .one solution is am installation of an Rond Stary Voltage blocker . . .I have zero experience with these..but I am about to . . . .that bring said . . .if the blocker device works....problem solved . . . .I thinkone excellent adition to the ciode would be a mandate for a recorded/approved printed /but simple plan for any future swimming pool installation as to its INSTALLED required electrical components

man that would sure be handy right now since we'd have to excavate the pool to know what was or was not installed fr bonding/grounding

 

[don_resqcapt19]

The neutral blocker would have to be installed by the utility...it only does its job if it breaks the connection between the utility primary and secondary grounded conductors.

 

[don_resqcapt19]

Gar,
With your measusred voltages in the milivolt range, they could be from any number of nautral causes.

 

[charlie]

The neutral blocker would have to be installed by the utility...it only does its job if it breaks the connection between the utility primary and secondary grounded conductors.

Exactly, and normally, the primary neutral and secondary neutral are the same. :smile:

 

[gar]

080524-0840 EST

charlie:

You may be correct that it is a Y source. My pole has 3 primary wires. It is possible that one is a neutral. None of the 3 overtly connect to the pole ground rod. So if a primary neutral was connected to the ground rod, then it would have to be internal to the transformer. It is hard for me to trace thru many backyards and trees to see how various transformers are connected to the primary lines.

At my shop the same kind of primary pole wiring exists, and the pole transformer primaries are wired delta.

From this limited information can you still assume the primary source is Y?


don_resqcapt19:

What natural cause produces an AC current in the earth surface?

.

 

[charlie]

From this limited information can you still assume the primary source is Y?

Yes, because the delta primary distribution is almost non-existent in the US.

I am betting that there are actually three wires on the cross arm or above the transformer. Additionally, there will be another wire that is under the transformer that is the neutral and it will be connected to the pole ground. This wire is normally in parallel with the secondary neutral or is the same wire as the secondary neutral. :smile:

 

[don_resqcapt19]

don_resqcapt19:
What natural cause produces an AC current in the earth surface?

Take a look here
or here.