electrolysis issue 1 volt DC on the copper plumbing with the main off!

[ElectricVette]

Here is the problem... the house is 4 years old very nice custom home. The water has a aqua blue color when you first run the faucets then clears out after a few seconds. Blue ring in all the toilets ect. House has a Ufer ground, gas hot water for in-floor heat and domestic hot water. 200 amp CH panel all grounds and neutrals tight. Power company came out and tighten the wires on the line side of the meter. I pounded a 8' ground rod outside and ran a #10 copper into where the bond hits the gas and hot & cold above the water heater. We turned off the 200 main and my meter still read 1 volt DC! Crazy i say crazy! :happysad: Could it be electronics inside the house bleeding voltage and/or a poor ufer? Any ideas on where the mystery voltage is coming from?
Thanks Tim

 

[ptonsparky]

When was your meter last calibrated?

What were you measuring from and to what? Look for current flow.


Before you get to worked up over 1 volt, have a water analysis done.

 

[zbang]

Is there a dielectric union in the water line? I've heard of cases where the entire water system was carrying relatively massive currents, and that caused blue water.

 

[lazorko]

Meters with high input impedances can give funny readings if you're not certain of what you're seeing. Put a finger on one probe, the other waiving in the air - FREE VOLTAGE! Wave it more - stick the probe under your arm! Or..em. Just kidding. Note that as there are currents passing through the earth and air from a myriad of sources, you should be able to measure some of them. We live in electricity. I am certain that none of these would make the water turn blue. Red maybe (just kidding, of course. I think only those little pottie-cleeners in the tank do that).
Why are you posting? is there an operational problem aside from the toilet water hue?

 

[mtfallsmikey]

Similar situation many years ago, had voltage between the tub faucet and drain, voltage with main shut off, POCO xmfr. was bad.

 

[kwired]

Similar situation many years ago, had voltage between the tub faucet and drain, voltage with main shut off, POCO xmfr. was bad.

But if coming from the utility it should be AC voltage.

Chasing something on the utility side is generally not going to produce anything causing the problems - the utility is not a DC source. Telephone or cable TV is a potential DC source and you need to eliminate those possibilities as well.

As has been mentioned is there dielectric unions? Any dissimilar metals can create a crude battery, and depending on the pH of the water, it can improve its electrolyte properties and make a somewhat improved battery.

 

[Jon456]

Meters with high input impedances can give funny readings if you're not certain of what you're seeing.

In my experience, phantom voltages are always AC (due to capacitive coupling or induction). I agree with kwired: if the OP is seeing a DC potential, it's most likely due to electrolysis of dissimilar metals. After tracking down the problem, it would be a good idea to check and -- probably replace -- the anode rod in the water heater.

 

[mtfallsmikey]

But if coming from the utility it should be AC voltage.

Chasing something on the utility side is generally not going to produce anything causing the problems - the utility is not a DC source. Telephone or cable TV is a potential DC source and you need to eliminate those possibilities as well.

As has been mentioned is there dielectric unions? Any dissimilar metals can create a crude battery, and depending on the pH of the water, it can improve its electrolyte properties and make a somewhat improved battery.

It was A.C., but understand that this incident happened some 30 yrs. ago, HO was getting shocked when they got in the tub, which was C.I. Cable TV?...only cable back then was twin lead from the big Channel Master antenna...my brother and I were discussing this not long ago, he worked in Dad's biz as well.... POCO replaced the transformer, and service was replaced, problem solved. Yes, dissimilar metals were there, Water lines were galv./copper mix, drains were galv./C.I. Old house, built in early 50's, this was typical.

 

[K8MHZ]

Meters with high input impedances can give funny readings if you're not certain of what you're seeing. Put a finger on one probe, the other waiving in the air - FREE VOLTAGE! Wave it more - stick the probe under your arm! Or..em. Just kidding. Note that as there are currents passing through the earth and air from a myriad of sources, you should be able to measure some of them. We live in electricity. I am certain that none of these would make the water turn blue. Red maybe (just kidding, of course. I think only those little pottie-cleeners in the tank do that).
Why are you posting? is there an operational problem aside from the toilet water hue?

That's one reason I still keep an analog meter around.

Water turning blue probably means there is a copper salt present. That means besides copper and water, there has to be something else there and electricity won't put it there. That something else will usually be chlorine. Or sulfur.

A water test is prudent before electrolysis can be suspected.

 

[mtfallsmikey]

That's one reason I still keep an analog meter around.

Water turning blue probably means there is a copper salt present. That means besides copper and water, there has to be something else there and electricity won't put it there. That something else will usually be chlorine. Or sulfur.

A water test is prudent before electrolysis can be suspected.

Yea Marky, our fav meter back then was a Sperry Snap 6, still have that and a Wiggy... :/

 

[K8MHZ]

Yea Marky, our fav meter back then was a Sperry Snap 6, still have that and a Wiggy... :/

My favorite was my Triplett until it met it's demise due to an untimely fall off the top of a ladder. I don't know what brand the one I have left is, but it still works and I do use it occasionally.

My 'wiggy' is the Ideal XL version. I really like it.

 

[kwired]

It was A.C., but understand that this incident happened some 30 yrs. ago, HO was getting shocked when they got in the tub, which was C.I. Cable TV?...only cable back then was twin lead from the big Channel Master antenna...my brother and I were discussing this not long ago, he worked in Dad's biz as well.... POCO replaced the transformer, and service was replaced, problem solved. Yes, dissimilar metals were there, Water lines were galv./copper mix, drains were galv./C.I. Old house, built in early 50's, this was typical.

OP is claiming he has a DC problem is why I mentioned it is not the POCO if it is a DC problem - they are not a DC source.

 

[zbang]

OP is claiming he has a DC problem is why I mentioned it is not the POCO if it is a DC problem - they are not a DC source.

If, in fact, there is a DC component (now much current?), then I'd be heading to the water company; some will put a low-voltage DC on pipeline segments to prevent electrolytic corrosion. OTOH, they're probably deny any problem until smacked in the face with it. They're may also be a pH problem with the water

Google search for "blue water corrosion":
http://www.lsuagcenter.com/en/our_o...al+water+systems+corrosion+and+blue+water.htm
http://www.ct.gov/dph/lib/dph/envir.../35_Corrosion_of_Copper_Pipe_and_Fittings.pdf

 

[kwired]

If, in fact, there is a DC component (now much current?), then I'd be heading to the water company; some will put a low-voltage DC on pipeline segments to prevent electrolytic corrosion. OTOH, they're probably deny any problem until smacked in the face with it. They're may also be a pH problem with the water

Google search for "blue water corrosion":
http://www.lsuagcenter.com/en/our_o...al+water+systems+corrosion+and+blue+water.htm
http://www.ct.gov/dph/lib/dph/envir.../35_Corrosion_of_Copper_Pipe_and_Fittings.pdf

The problem may entirely be on customer premises and if so water company will not really care, as long as it isn't being subjected to their piping, which a dielectric union or other isolation method will likely do the trick.

pH levels could be the water company problem, but I'm guessing minimum health standards which is what they would be required to meet allow enough variance from a neutral pH to still become a sufficient electrolyte solution, maybe not an ideal electrolyte if you wanted to build a battery but sufficient enough to start some problems with electrolysis.

 

[ElectricVette]

getting closer to solving the mystery

getting closer to solving the mystery

When was your meter last calibrated?

What were you measuring from and to what? Look for current flow.


Before you get to worked up over 1 volt, have a water analysis done.

I was measuring from the #10 off the ground rod to the copper at the water heater. Owner is getting the water tested. The plumber is saying it is not electrolysis because the problem is everywhere in the house. I tend to agree with that analysis.

 

[meternerd]

OP didn't say, but is there also AC voltage with the main off? With many high impedance meters, any AC voltage can cause the meter to read slight DC voltages on the DC setting. Probably has to to with the electronics of the meter. If you are seeing AC voltage as well, load the circuit slightly with a resistance in parallel with your meter and see if the voltage goes away. If so, it's phantom voltage and there's not enough current available to do much of anything. Chemicals in the water is more likely the culprit.