Shocked from the waterline

[JMahaney]

Hi I am doing a diagnostics at a customers house that stated that the water company was getting shocked when they tried to change her meter.
On arrival I checked the amperage on my waterline bond and it was 14 amps. I verified that we do have a good ground coming from the power company. At that point I started to turn off individual branch circuits I found the 20 amp breaker that was causing my 14 A on the waterline. Space heater was running. This is an older home with a ungrounded system.
My question is what would cause the waterline to have voltage potential?

 

[xformer]

IMHO, I would say since the house was ungrounded, the 14 amp circuit had lost a neutral and was using the waterline as a neutral back to the source.

 

[tom baker]

An open neutral between the service and POCO transformer. If the customer has a metallic water service line, then the unbalanced current is returning via the water line, a neighbors water line, via their service to the POCO
What do you mean by "I verified that we do have a good ground coming from the power company", as the POCO does not provide a ground

 

[ptonsparky]

Hi I am doing a diagnostics at a customers house that stated that the water company was getting shocked when they tried to change her meter.
On arrival I checked the amperage on my waterline bond and it was 14 amps. I verified that we do have a good ground coming from the power company. At that point I started to turn off individual branch circuits I found the 20 amp breaker that was causing my 14 A on the waterline. Space heater was running. This is an older home with a ungrounded system.
My question is what would cause the waterline to have voltage potential?

Guessing you mean the water line is not bonded to the SE neutral when you say 'ungrounded'. Is that correct?

Look at your heater and determine how the fault current is getting to the water pipes. You are a step ahead because you have determined what is giving you grief.

Bond the water lines.

 

[JMahaney]

IMHO, I would say since the house was ungrounded, the 14 amp circuit had lost a neutral and was using the waterline as a neutral back to the source.

Thank you for replying! Does that also mean somewhere on this circuit a ground or Neutral is connected to the waterline possibly in the wall?

 

[JMahaney]

IMHO, I would say since the house was ungrounded, the 14 amp circuit had lost a neutral and was using the waterline as a neutral back to the source.

An open neutral between the service and POCO transformer. If the customer has a metallic water service line, then the unbalanced current is returning via the water line, a neighbors water line, via their service to the POCO
What do you mean by "I verified that we do have a good ground coming from the power company", as the POCO does not provide a ground

I removed the grounded conductor from the panel coming from the power company with the main off and tested voltage from phase to ground and it was showing proper voltage. That’s why I do not believe this is an issue coming from the power company side. Also I lose the amperage on the waterline when one single branch circuit is turned off thanks

 

[JMahaney]

I removed the grounded conductor from the panel coming from the power company with the main off and tested voltage from phase to ground and it was showing proper voltage. That’s why I do not believe this is an issue coming from the power company side. Also I lose the amperage on the waterline when one single branch circuit is turned off thanks

Also what do you mean by the power company does not provide a ground?

 

[JMahaney]

Guessing you mean the water line is not bonded to the SE neutral when you say 'ungrounded'. Is that correct?

Look at your heater and determine how the fault current is getting to the water pipes. You are a step ahead because you have determined what is giving you grief.

Bond the water lines.

No the waterline is bonded also there is a ground rod. All I meant by the house is ungrounded is that it’s a two wire system without ground on the branch circuits.

 

[xformer]

Thank you for replying! Does that also mean somewhere on this circuit a ground or Neutral is connected to the waterline possibly in the wall?

That is possible. Or laying across the waterline under the house. Tom and Ptonsparky bring up good possibilities as well. If the one circuit is the source of the issue, then I would make sure water line is bonded.

 

[augie47]

If you disconnected incoming grounded conductor and still measure voltage phase to ground then your water line is likely the path.
Keep in mind if there are more residences on the transformer the current could be coming from a bad POCO connection at another residence seeking a path thru your neutral.
The lilkyhood of it being a POCO problem is still very probable.

 

[tom baker]

Just a note, in discussing grounding and bonding, it helps to use code terms, The two wire system has no equipment grounding conductor, for example. Look up ground in the definitions of the NEC...
Mike Holt once said in discussing grounds "what color is it and what does it do?"

 

[JMahaney]

I’ll definitely work on that thanks for deciphering my wrong terminologies.

 

[synchro]

Did you verify that when loads are applied on other branch circuits in the panel that this has a minimal effect on the current through the waterline? If so then it's likely that the connection from the service grounded conductor to the panel neutral bar is intact. The voltage between the neutral bar and panel should be measured to make sure it's very low even when loads are applied.

If the problem is isolated to the one branch circuit, then the neutral conductor of this branch circuit is probably connected to the panel ground bar (or some other connection to the EGCs) instead of the neutral bar. Also the bonding screw or jumper between the neutral bar and panel is likely to be missing or disconnected (because if it was connected then the current would return on the POCO's neutral which should have a lower resistance path to the transformer than the waterline).

 

[Joe.B]

You have a two-wire, "ungrounded" system, meaning there is no equipment grounding conductor. Are all of the outlet receptacles proper two-prong or GFCI protected? I have run across many houses in my area that were "updated" to three-prong outlets so that renters wouldn't complain but they were done DIY style with no EGC, or worse, with a "bootleg ground". Does the electric space heater have a three-prong plug meaning that it requires an equipment ground? Probably not, just looking to rule some things out for you.

 

[ptonsparky]

No the waterline is bonded also there is a ground rod. All I meant by the house is ungrounded is that it’s a two wire system without ground on the branch circuits.

Changes everything.
Now you need to look for open neutral from the POCO transformer on in as others have stated. Purposely opening that POCO grounded conductor (neutral) is not generally a good idea. It would be better to amp clamp it and the water line as you change loads. Even on good neutrals there may be some flow of current on the water line, but significantly less than that of a good neutral conductor/connection.
Get your meters out and start checking voltages L1-N and L2-N as well as current. Multiple meters are a big help.

 

[JMahaney]

You have a two-wire, "ungrounded" system, meaning there is no equipment grounding conductor. Are all of the outlet receptacles proper two-prong or GFCI protected? I have run across many houses in my area that were "updated" to three-prong outlets so that renters wouldn't complain but they were done DIY style with no EGC, or worse, with a "bootleg ground". Does the electric space heater have a three-prong plug meaning that it requires an equipment ground? Probably not, just looking to rule some things out for you.

Correct no equipment grounding conductors.
Unfortunately yes all receptacles have been changed to three prong, and yes the space heater has a three prong plug. If I’m missing possibly missing the neutral. How does the return path transfer to the waterline unless it’s connected somewhere else in the house to the waterline?

 

[Joe.B]

You mentioned earlier that the water line was bonded. Or a fault elsewhere. I think this is why people here are suggesting that the POCO may have a faulty neutral. If the neutral (Grounded Conductor) on the meter side is faulty then the current would use the path of least resistance to get back to source. The metal waterline is that path.

Also if you get involved in this project you may want to consider returning all of those outlets back to two prong or upgrade to GFCI. If something goes wrong down the road and you were the last one working on that system you could be on the hook.

 

[Joe.B]

It sounds like you need to isolate the problem. Follow ptonsparky's advice and consider trying the heater on a different circuits, and/or finding another heavy load to try.

There is a possibility that someone wired the new outlet with a "bootleg" ground, meaning they have tied the ground to the neutral, or rather they have connected what should be the equipment grounding conductor to the grounded conductor. If the heater has an internal fault this could be a dangerous situation. This is why I am suggesting to approach this job carefully. You could have a can of worms here.

 

[hillbilly1]

I would venture a guess that a jack leg electrician previously lost the neutral on that circuit, and tagged it the the waterline under the house. Especially since it’s only that particular circuit. Is the space heater portable? Or a permanent mount? As others have said, the waterline is probably not bonded either. Also there should have been a bond jumper around the meter, if the water department is getting shocked when removing the meter, that bond is not present.

 

[synchro]

It sounds like you need to isolate the problem. Follow ptonsparky's advice and consider trying the heater on a different circuits, and/or finding another heavy load to try.

I agree with this. With a load like a space heater on one branch circuit, and with the other branch breakers turned off, try measuring the currents on the following conductors with a clamp meter if you can:
1. branch circuit hot
2. branch circuit neutral
3. service neutral conductor in the panel
4. grounding electrode conductor coming from panel

The #1 and #2 currents should of course be equal. If the neutral current is noticeably smaller than the hot conductor current in the branch circuit, then there must be another path such a bootleg ground in a newer circuit with an equipment grounding conductor.
The current #3 on the service neutral should be about the same as the current in the one branch circuit that is active. If you see little or no current then the service neutral may be open or have a poor connection upstream.
The GEC current of #4 should be relatively small but apparently is high in your case. Measure this current with the load placed on different branch circuits and check if it is always high or just on the branch circuit you mentioned.