I'm late to this thread but I am finding it very interesting. Could the 24V be coming from the incoming telephone lines or if you have cable TV hook-up, possibly from that. Maybe with the main breakers shut off, also disconnect the telephone lines at the incoming box and make a measurement.

 

Wild guess that just pop into mind. Are there any power transmission lines in the area of the house? Is there a radio or TV broadcasting tower close? 24V DC or AC doesn't seem like it should give a shock.

 

If there getting shocked there is more then 24 volt
I've run into this more then once. Last one I ran into was on the power side the bond to the ground was broke at the transformer and if you touched anything on the house side you got a nice shock.

What had happen was two part problem the house side was using water pipe as ground pipe broke someone fixed it with what looks like a pipe with two caps. So looking at the pipes it looks like there all metal.
The problem is the repair coupling has two rubber gaskets that break the bond.
Now outside looking at the pole there was a ground wire I pulled it was just sticking in the ground.

I jumpered the pipe repair and install new ground rod problem fixed.
.

 

I hope that my second edit to post#19 makes sense to everybody. All of that local grounding is not to make the circuit function, it is to reduce the shock hazard associated with assorted faults. And it probably reduces the hazard of starting fires electrically as well. And it still seems like there may be a lack of adequate connection between the distribution panel neutral busbar and the neutral connection from the utility pole. With aluminum connection cables that certainly can happen.

 

My turn to make some sense out of this.

The US has single phase power, but it's better described as split-phase. The transmission side could be on the order of 9.6 kV with the huse being a 240 V center-tapped transformer.

That center-tap gets connected to neutral, earth and metalic plumbing at ONLY one place.

The detached garage complicates things a little. Let's ignore it for the moment.

So what does this do?

It means if you touch a metal appliance whose case is grounded and a metal fixture you don;t get a shock. The appliance "protective ground" handles ground faults only.

Electric dryers are another problem. If you have one, is it 4-wire or 3-wire?

What we have done is to make the zero volt reference for the house, telephone and cable equal to Earth at the ground rod. A lightning strike can raise the potential of that rod, but it still is the house's 0V reference.

The detached garage has a problem. The garage's 0V can be different and we dont want that,
What happens in any sub-panel is ground, Neutral, L1 and L2 remain separated at the sub-panels.
If that line should get a strike we have problems UNLESS a separate ground rod is used for the DETACHED structure.

Now, the L1 and L2 thing and Neutral, If all the appliances were 240 V, then there would be no neutral current. If L1 had 5A and L2 had 5A there would be no neutral current.

If L1 and L2 had different currents relative to neutral, the neutral carries the difference. You can think of it as a sign, but really it's a phase difference, So L1 = 5A@0deg; L2 = 5A@180deg; N=0 ; Lets say 0 degrees is referenced to L1.
So, it's a vector sum. -5A (AC) is like yea, right? But , if you let a (-) stand for 180 degress out of phase it can make sense.

Odd things can happen with an electric water heater because it can connect L1 and L2 with a low resistance if one of them is missing,

If you look here http://www.farnell.com/datasheets/1576607.pdf#page=2, you will mot a leakage current of about 2uA.
If that ground were missing and not connected to earth, you would measure about 60V on the ground pin.

So, strange things can happen.

Follow the money.

Main panel: Verify the potential between the ground wire and Neutral
Find the connection of ground to the water pipes.

See where it gets lost.

You have an auxillary structure which might have a metal water pipe. I think if there is metalic piping in that structue, it should be boned to the ground rod for that structure. That's an alternate path back to the main panel.

So, find the point where the plumbing is connected to ground and see where it could potentially get lost.
e.g. water meters, dielectric unions, sections of PVC piping etc,

Places where things can get wierd too is the Telephone NID. A bad protector and a bad ground can create issues too.

If you have an electric dryer, you might want to unplug it. Electric stoves have a lesser potential for problems. Be careful if it's 3-wire and not 4.

I said to bisect to find the fault, It;s really called binary searching.

You check the reference and the end and verify there is a problem.
Then you check 1/2 way to the beginning. If there is no problem 1/2 way.

Dived the 1/2 way to full in 1/2.
so your measuring from the reference to the 3/4 point.

You keep diving by 2, to find out what section of pipe the problem is. You can find the issue very quickly.

If you had 1024 points, it would take something like log(1024)/log(2) or about 10 trials to find the broken point.

When you have a finite number of items, like 2000, the algorithm goes easier if you 1024, a power of 2, as the "middle" The next power of 2 is 2048.

 

That center-tap gets connected to neutral, earth and metalic plumbing at ONLY one place.

Not so in Utah (USA). I happen to have a power pole with transformer in my back yard. The high voltage line is accompanied by a grounded line. That grounded line is shared by the transformer. The Neutral line is tied to ground (again, in my back yard). At my house (the mast) is bonded to a ground rod just below where the incoming power enters the house. Inside the house (1964) the panel has a ground wire (attached to the same bus bar as the neutrals) that runs from the panel to where the water supply enters the house.

Odd things can happen with an electric water heater because it can connect L1 and L2 with a low resistance if one of them is missing,

Keep in mind the TS has stated he gets the shock even when the meter is removed. No electrical connection whatsoever except for the neutral line.

What I'm still waiting for an answer is that the TS says he's getting a shock. How? Where? Does the TS touch the washing machine and the water pipe? The stove and the sink? How? Where? You can't get a shock from just touching one side of a live system. You have to complete a circuit in order to get a shock. If you're touching two grounded things and getting a shock then one of them isn't properly grounded. Learned that in High School back in the 70's. Had a signal generator and an O-Scope. When I rested one hand on the scope and the other on the generator I'd get a pretty good buzz. Thought it was a bad outlet. Tried two different outlets and got another buzz. Checked the voltage between the two and it was 64 VAC. Thought it might be a bad grounded circuit. Nope. That wasn't the problem either. Must have been one of the two test equipment. It was.

Here's the point to keep in mind - the TS is getting a shock even when power is removed from the house. SOMETHING must be introducing the energy. Two questions: What could it be? Why isn't the ground pulling the potential away from the end user?

But most of all I still want to know exactly what the TS is touching when he gets a shock.

 

But most of all I still want to know exactly what the TS is touching when he gets a shock.

Agree that some definitive empirical testing has to be done to arrive at the correct conclusion.
Max.

 

Not so in Utah (USA). I happen to have a power pole with transformer in my back yard. The high voltage line is accompanied by a grounded line. That grounded line is shared by the transformer. The Neutral line is tied to ground (again, in my back yard). At my house (the mast) is bonded to a ground rod just below where the incoming power enters the house. Inside the house (1964) the panel has a ground wire (attached to the same bus bar as the neutrals) that runs from the panel to where the water supply enters the house.
Keep in mind the TS has stated he gets the shock even when the meter is removed. No electrical connection whatsoever except for the neutral line.

What I'm still waiting for an answer is that the TS says he's getting a shock. How? Where? Does the TS touch the washing machine and the water pipe? The stove and the sink? How? Where? You can't get a shock from just touching one side of a live system. You have to complete a circuit in order to get a shock. If you're touching two grounded things and getting a shock then one of them isn't properly grounded. Learned that in High School back in the 70's. Had a signal generator and an O-Scope. When I rested one hand on the scope and the other on the generator I'd get a pretty good buzz. Thought it was a bad outlet. Tried two different outlets and got another buzz. Checked the voltage between the two and it was 64 VAC. Thought it might be a bad grounded circuit. Nope. That wasn't the problem either. Must have been one of the two test equipment. It was.

Here's the point to keep in mind - the TS is getting a shock even when power is removed from the house. SOMETHING must be introducing the energy. Two questions: What could it be? Why isn't the ground pulling the potential away from the end user?

But most of all I still want to know exactly what the TS is touching when he gets a shock.

Keep in mind that when the meter is removed the neutral wire is still very solidly connected to the neutral wire entering the house. Last summer I was at a campground where folks were getting shocks off ot the water valves in the shower. So the power companyfolks came up and did a bunch of work on their big transformer installation where the power entered the campground, and eventually the problem was solved. The rather cryptic explanation that I got was "A bad connection". And it does not seem like any of my previous questions have been answered or even addressed. Those answers would probably help the experts provide a solution.
My suggestion now is to temporarily disconnect all three wires, L1, L2, AND neutral, and then check the supply neutral voltage relative to a ground rod connection. But be very careful to disconnect L1 and L2 FIRST!!!

 

Not so in Utah (USA). I happen to have a power pole with transformer in my back yard. The high voltage line is accompanied by a grounded line. That grounded line is shared by the transformer. The Neutral line is tied to ground (again, in my back yard). At my house (the mast) is bonded to a ground rod just below where the incoming power enters the house. Inside the house (1964) the panel has a ground wire (attached to the same bus bar as the neutrals) that runs from the panel to where the water supply enters the house.

That doesn;t change what I said.

Copper plumbing, Earth and Ground connect at only one place.

There is usually aground at the pole too, but no copper plumbing out there.

 

That doesn;t change what I said.

Copper plumbing, Earth and Ground connect at only one place.

There is usually aground at the pole too, but no copper plumbing out there.

Plumbing, be it copper or galvanized pipe - the point is that it acts like a grounding rod. In leu of a lack of pipes out back by the power pole, the rods they drive into the ground with the guy wires for stabilization are also used for electrical ground. Such is the case in my back yard, and is how the transformer on the pole (in my back yard) the neutral IS grounded.

 

...Earth and Ground connect at only one place.

Ground can be "earthed" many places. For residential service there must be at least one (and in some locales at least two) ground rods near the power entry or main panel.

Ground and NEUTRAL connect at only one place. This is usually at the main breaker panel via a bonding screw, but can be done by other means. I know this is splitting hairs in verbiage, but the distinction must remain clear that neutral and ground serve two different functions. Neutral carries return current from the hot lines. Ground does not normally carry current and only does carry current during a fault condition.

The location of the ground for copper pipe is not as critical as the neutral-to-ground connection. Often the easiest location is near the main breaker panel.

 

Agree that some definitive empirical testing has to be done to arrive at the correct conclusion.
Max.

Neither one of those questions has been adequately answered by the TS. Nor any of my questions. Insread we have lots of guesses and conjecture. Knowing what some codes require is not at all the same as finding out the details of the place where the posted problem lies. Knowing what should be is not very useful in understanding "what is." I am guessing that the TS is getting a shock when standing on the ground outside and touching a water faucet valve handle. That is a reasonable GUESS, but it is only my guess, with no claim that it is right.

 

Power was measured initially from outside ground rod to ground (24V), outside water spigot to ground (24v) and then measured again after main outside was turned off with the same 24v in both location

would it be incorrect the issue has to either be in ground wiring to house or in transformer or company power lines?

Ground = third prong of outdoor outlet? Meter case? Problem with definition.

Example issue:

Neutral-ground bond loose/broken before main panel. This typically happens with overhead lines near the "masthead" for lack of a better word.

The neutral-ground bond gets made indirectly via the garage or even a neighbor's plumbing. That's a typical problem.


Plumbing not bonded to ground can be another.

An aside: Current carrying connections/breakers can be checked by measuring the voltage across the connection.

 

The one thing that has not been disconnected is the neutral line in the feed from the pole. Disconnecting the two power phases and having that voltage remain shows that the voltage is not being somehow generated inside the house, unless there is some magical generation system someplace that has not been discovered. So the next step will be to completely disconnect that neutral wire, AFTER disconnecting the two feed wires. That will probably be less convenient to do, although it should be accessible inside the meter box.
One other thing to try is putting a clamp-on ammeter around the entrance cable with the two line wires disconnected, which for this check could be as simple as switching off the mains. After some more thought it seems to me that there may be a fair amount of current flowing in the ground conductor, and opening the neutral lead may result in a much higher voltage from the incoming neutral to ground than the present 24 volts. Using a clamp on ammeter will reveal if there is much current flowing, and it does not require disconnecting anything or probing any live wires.