Amperage to ground

Status
Not open for further replies.
K

Kleinbag220

New member
Location
Southampton NY USA
Good afternoon,
i have a situation on a project where we are being blamed for the green water stains in the toilets being caused by electrolysis. This is a large service and a large building. We have a 2000a 3phase 208v MDP with 23 separate sub panels throughout the house, not including lighting control panels. We have parallel feeders coming into the house with ground wires sized to the feeders.(6 sets) Putting a clamp on meter on the ground wire at the MDP gives me a variable reading anywhere between 1.2 and 4.9 amps, but I can get no voltage reading using the same method.
As I turn off equipment, the reading goes down...
is this normal and is it a cause for the electrolysis?
 
Those few amps are normal, you have a 2000A service, so a little current on the Grounding Electrode Conductor is to be expected.

I do not believe electrical is the cause of the stains, more likely a plumbing issue IMO.
 
The notion that anything electrical can cause stains in a toilet is laughably (or perhaps tragically) stupid. This is a chemistry issue that would be caused by something in the water supply, or something that the building uses to treat the water.

In order to answer your question about the current (and absence of voltage) readings, I would need to know what you mean by "meter at the ground wire." Where is the N-G bond? If it is at the main panel (not at the transformer), that would mean that the grounding electrode conductor (GEC) would be connected to the N bus at the main panel, and would run (along some path) from there to planet Earth. Is that the wire to which you attached the clamp-on meter?
 
I think it is far more likely the green water stains have been caused by scrubbing the porcelain with something abrasive and then either algae or more likely copper compounds causing the stains.

Does the facility use well water? Even if not, has the city water been tested for metals?

this is not the first time I have seen electrical blamed for plumbing and or housekeeping problems, but it is perhaps the most laughable as the above poster mentioned..

do your tests, collect your paycheck, however I think the probability of electrical causing this is greater than the odds of winning the Powerball lottery.

I have seen green discoloration in industrial porcelain toilets, Crane manufacturer to be specific, at jails.

Welcome to The Forum.

Edited to add... Housekeepers adding chemicals to the tank like a 2000 flushes type cake could also be responsible for the stains.
 
I can assure you that the "green water stains caused by grounding" is a myth. This question has come up before and the answer is its a water quality issue. Water with a low pH is aggressive and dissolves the protective oxide film on copper pipes and also lead solder. To comply with the EPA lead and copper rule (1995?) water purveyors were required to survey certain customers and if required, treat the water by raising the pH (corrosion control)
Our water is about 7.5 to 8.0 depending if ground or surface, and we raise the pH by adding a chemical, to 8.5. We started this in 1999 and long term it has been very successful.
Failure to do corrosion control was the main issue in Flint, by the way.
I also have the definitive study by the American Water Works Association, on grounding and corrosion. In almost all cases, corrosion and resulting green stains are caused by DC currents, not AC.

What you should do is contact your water supplier. Ask for copy of the water system consumer confidence report.
This is more than you want to know, see page 3 on this report
https://www.awwa.org/portals/0/files/publications/documents/m58-2lookinside.pdf

I work for a large water utility and am somewhat knowledgeable about corrosion control...
 
Kleinbag220 said:
Good afternoon,
i have a situation on a project where we are being blamed for the green water stains in the toilets being caused by electrolysis. This is a large service and a large building. We have a 2000a 3phase 208v MDP with 23 separate sub panels throughout the house, not including lighting control panels. We have parallel feeders coming into the house with ground wires sized to the feeders.(6 sets) Putting a clamp on meter on the ground wire at the MDP gives me a variable reading anywhere between 1.2 and 4.9 amps, but I can get no voltage reading using the same method.
As I turn off equipment, the reading goes down...
is this normal and is it a cause for the electrolysis?
Click to expand...
Doesn't electrolysis use DC?
 
Kleinbag220 said:
Good afternoon,
i have a situation on a project where we are being blamed for the green water stains in the toilets being caused by electrolysis. This is a large service and a large building. We have a 2000a 3phase 208v MDP with 23 separate sub panels throughout the house, not including lighting control panels. We have parallel feeders coming into the house with ground wires sized to the feeders.(6 sets) Putting a clamp on meter on the ground wire at the MDP gives me a variable reading anywhere between 1.2 and 4.9 amps, but I can get no voltage reading using the same method.
As I turn off equipment, the reading goes down...
is this normal and is it a cause for the electrolysis?
Click to expand...

I will expound on what Jumper said.
Since there is no perfect insulator there will be current flow on the neutral (wye) to ground conductor on any distribution system. Capacitive coupling can add to this. The amount of current (leakage) is proportional to the load current of the 3-phase system. I seem to recall that Westinghouse used a rule of thumb where this current can be in the range of 1% of the system load current.
If these currents become excessive, I would look downstream for loose neutral connections.
As far as this causing the green water stains, I would tend to go with the consensus of the other replies.
 
Besoeker said:
Doesn't electrolysis use DC?
Click to expand...
Electrolysis takes place under an applied DC voltage. In either direction. What changes is which electrode material is removed from and which is is deposited on.
If the applied voltage is balanced AC, the effects will tend to cancel out, but some metal will end up lost from each end into the soil or other surrounding area. And a thin metal plating will become non-uniform in thickness, developing pinholes.

So DC will cause the fastest, most consistent damage, but AC is harmful too, depending on the environment.
 
I know this has already been beat into the ground (no pun intended), but how could electrolysis occur between the water and a toilet bowl that is basically an insulator. The dielectric strength of porcelain is between 200-500 volts per mil of thickness. I don't care if you have a bank of car batteries connected between the grounding system and the toilet bowl, no current is flowing to it. I just don't know how or why anyone would even entertain the notion that electrolysis is happening. It makes me turn green just thinking about it.
 
rlundsrud said:
I know this has already been beat into the ground (no pun intended), but how could electrolysis occur between the water and a toilet bowl that is basically an insulator. The dielectric strength of porcelain is between 200-500 volts per mil of thickness. I don't care if you have a bank of car batteries connected between the grounding system and the toilet bowl, no current is flowing to it. I just don't know how or why anyone would even entertain the notion that electrolysis is happening. It makes me turn green just thinking about it.
Click to expand...

You are oversimplifying both the description of the problem and the common explanation:

Yes, no electrolysis (nor electrodeposition) is taking place in the toilet bowl. But electrolysis involving copper pipes anywhere in the supply side of the system can result in copper ions getting into solution in the water, particularly if the salt concentration in the water is on the high side to start with.
As the water in the bowl evaporates between flushes, the dissolved copper salts could precipitate out. This will not happen as much in the tank, as the water does not evaporate as fast there. You would also see signs of green where faucet drips evaporate too.

And, as stated several times in earlier posts, the root of the problem is most often inadequate corrosion control, not electrolysis, that is putting the copper salts into solution in the first place. But electrolysis could contribute.
 
Status
Not open for further replies.
Top