# shock in shower



## tbwoods (Jul 6, 2009)

HI,

I recently purchased a new place. For 1 year no problem. Just this weekend though, 2 people have gotten shocked in the shower when touching either the shower head or on/off handles. I've done a lot of checking and here is what I know:

I have continuity between the plumbing (shower head, valve) and the neutral bar in my electrical panel - where all white wires are attached. (10 feet away)

I put a volt meter between the shower head or valving and the floor drain in the shower stall floor. The piping is plastic but full of water. I get 22 to 50 volts AC.

The electrical panel is 10 feet from the shower. The unit is new 200 amp service and has a heavy copper line going from the panel to a grounding rod driven in the ground about 10 feet away.

I exhaustively went through my panel, disconnecting one circuit at a time. I found that when I remove the electric water heater breaker and grounding wire from the heater to the panel, the voltage drops to 4 or 5 volts between shower plumbing and floor drain. This is with every possible electrical device running. If I shut off big items like oven, and electric base board heaters, it still stays around 4 to 5 volts AC. I get the same voltage readings stated above between shower floor drain and the common bar in the electrical box. I guess this makes sense since I have continuity between shower faucet and electrical box common bar.

If I shut the main breaker, with water heater disconnected from the elextric box, I get 0 volts for all readings when the water heater is disconnected. 

I have a well. The pipe from the well to the inside of the house is plastic.

I believe I have a water heater problem with the 22 t0 50 volts showing up and was going to call the manufacturer today.

Here are my questions: 

1. Should I also be concerned about the 4 to 5 volts that is always present with the electric water heater disconnected? 

2. There seems to be a major problem with the water heater. What can cause the 22-50 volts to be present? If this is a failed element, can i put some safety device in place to prevent this voltage from getting to the shower?

All of these devices are withing 20 feet of each other.

Any advice on grounding, etc.. to fix this problem is appreciated. What is bonding? Should I provide further ground my plumbing? 

Thanks
tbwoods


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## tbwoods (Jul 6, 2009)

A quick clarification. My water supply lines are all copper. My drain lines are all plastic including the drain in the shower but it has a metal screen on top of it. I have a septic system.


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## AndrewF (Dec 29, 2008)

Can you confirm that you have a ground coming from the ground bus bar of your panel to you water lines?

If you do not, you are required to have one.


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## InPhase277 (Feb 9, 2008)

The 5 volts is likely a phantom due to the very presence of electricity when the main is on. The 50 V when the water heater is on is another problem entirely. It sounds like the metal plumbing of the house is not grounded properly. There should be solid electrical continuity between all metal parts of the plumbing system. The main metal water line should be connected to the neutral bus in the main panel, by code within 5 feet of where the pipe enters the house. The hot and cold pipes at the water heater should be jumped together with a conductor. Since your panel and water heater are so close together, you may be able to solve all the problems at once. 

You can jump the hot and cold lines together with a piece of #4 copper and continue that to the panel. Also, you need to troubleshoot the elements of the heater to see which one is leaking current, and replace it.


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## jbberns (Jul 1, 2009)

tbwoods said:


> HI,
> 
> I have a well. The pipe from the well to the inside of the house is plastic.
> 
> tbwoods


Your water lines should not be grounded. Even if your lines in the house are copper. I'd say that is your problem. Ran into a problem like this a few years back. Only they had replace a small section of pipe outside with plastic. Took a lot of head scratching. They were getting shocked everytime they were in the shower and the phone rang.


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## Code05 (May 24, 2009)

jbberns said:


> Your water lines should not be grounded.


 What about 250.104? It seems to say otherwise.


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## jbberns (Jul 1, 2009)

Ok, I looked. Didn't see enough to justify. More specific, please.


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## Code05 (May 24, 2009)

jbberns said:


> Ok, I looked. Didn't see enough to justify. More specific, please.


 " Shall be bonded" Seems pretty clear.


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## jbberns (Jul 1, 2009)

Ok, where does it say water lines that are fed with plastic have to be grounded?


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## jbberns (Jul 1, 2009)

Is your panel grounded? Did the wire to the ground rod get broken?

The water lines can't be considered a ground, because they don't have continuity with the earth.


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## Code05 (May 24, 2009)

tbwoods said:


> A quick clarification. My water supply lines are all copper.





jbberns said:


> Ok, where does it say water lines that are fed with plastic have to be grounded?


Who said anything about bonding plastic?:huh: Metal piping is what is being bonded. The feed into the copper lines need only be bonded if metal, and then it would become part of GEC system.


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## jbberns (Jul 1, 2009)

AndrewF said:


> Can you confirm that you have a ground coming from the ground bus bar of your panel to you water lines?
> 
> If you do not, you are required to have one.


Here it says that


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## jbberns (Jul 1, 2009)

Code05 said:


> What about 250.104? It seems to say otherwise.


That is talking about bonding not grounding.


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## tbwoods (Jul 6, 2009)

There is a ground wire from the panel to a rod outside the house. And just to confirm, the feed piping from the well is plastic into the house then goes to copper.

I'll have to remove some panneling to see if the water pipes are grounded to the electrical panel. I see continuity between the shower head and electrical panel ground but can't see a heavy ground wire exiting the box to anywhere but the outside grounding rod.

Also - Here are some more measurements I took. Without the water heater connected (white, black or ground), I measure voltage from the electrical box ground bar to the shower drain and get about 5 Volts. It does not go up even with other items turned on such as the electric stove, base board heaters, etc.. 

But when I hook up the water heater, now the voltage between the shower water supply plumbing (faucet/head) and shower drain goes up as additional electrical items are turned on. For example, the electric heater may cause a rise of 25 volts, then the stove is turned on and it voltage goes up more, then the well pump kicks on and goes up even more. With everything on, I can see up to 50 volts AC. But totally disconnect the water heater (white, black, and ground) and I only get 5 or 6 volts no matter what else is turned on. I see no rise or fall with other items on or off.


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## tbwoods (Jul 6, 2009)

To answer an earlier question, I checked and the ground wire from the panel to the grounding rod outside and the wire is in tact. I removed both ends and reconnected them.


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## jbberns (Jul 1, 2009)

I would say you shouldn't have a ground going to any part of your copper water lines. The only place it could get energized is at the water heater. Even there I don't think it should, so there is no reason to bond it there.


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## tbwoods (Jul 6, 2009)

I MADE A MISTAKE IN THE POST ABOVE. SEE CORRECTION BELOW.

Also - Here are some more measurements I took. Without the water heater connected (white, black or ground), I measure voltage from the electrical box ground bar to the shower drain and get about 5 Volts. It GOES UP SIGNIFICANTLY TO 30 + VOLTS OR MORE AS OTHER ITEMS ARE TURNED ON such as the electric stove, base board heaters, etc.. BUT WHEN I MEASURE BETWEEN THE SHOWER HEAD AND SHOWER DRAIN, THE VOLTAGE STAYS CONSTANT AT ABOUT 5 VOLTS EVEN THOUGH OTHER ITEMS ARE TURNED ON OR OFF.

But when I hook up the water heater, now the voltage between the shower water supply plumbing (faucet/head) and shower drain goes up as additional electrical items are turned on. For example, the electric heater may cause a rise of 15 volts, then the stove is turned on and it voltage goes up more, then the well pump kicks on and goes up even more, ETC. UNTIL YOU ARE AT 50 VOLTS. With everything on, I can see up to 50 volts AC. WITH WATER HEATER CONNECTED, THESE READINGS ARE THE SAME AS IF I WAS MEASURING BETWEEN THE BOX GROUND AND THE SHOWER DRAIN. BOTH GO UP AS ADDITIONAL ITEMS ARE TURNED ON. But totally disconnect the water heater (white, black, and ground) and I only get 5 or 6 volts no matter what else is turned on. I see no rise or fall with other items on or off when measuring betseen shower head and shower drain.


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## tbwoods (Jul 6, 2009)

Also, in case there is any confusion, I have all copper in the house but is fed by a plastic line from the well.


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## InPhase277 (Feb 9, 2008)

jbberns said:


> I would say you shouldn't have a ground going to any part of your copper water lines.


My friend, you are DEAD wrong here. All electrically conductive materials that form parts or pieces of any mechanical system, be it an appliance or building method, should be bonded. Metal water lines SHALL be bonded to the grounding system, as per *250.4(A)(4)* and *250.104(A)*. 

Bonding metal water lines and using them as grounding electrode conductors are two different, but related subjects. IF a water line is in contact with the earth for more than 10 feet, it is required by *250.52(A)(1)* to be used as a grounding electrode.

In the OP's case, the incoming water line is plastic, so it is not required to be used as an electrode. However, it transitions to copper, which is required to be be bonded by 250.4(A)(4) and 250.104(A).

A _journeyman_ should know that metal piping, above almost anything else, should be bonded. See post #4.



> The only place it could get energized is at the water heater. Even there I don't think it should, so there is no reason to bond it there.


No sir, not true. It could get energized literally _anywhere_. I think the most likely spot is the water heater, but it is simply not true that it can't be from a fault somewhere else.


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## Stubbie (Jan 7, 2007)

Two things cause you to get shocked in the shower when touching metal...

1.) Fault current.....

2.) NEV.....neutral to earth voltage

Since the pipes serving your home from the well are plastic then neutral to earth issues become less of a possible cause. Your pipes are not bonded to the service grounded conductor so it becomes even less of a possible cause.

Don't forget communiction/data cables but again neutral current cannot get to the pipes in this case if they are not bonded to the GES or to the system grounded conductor. Assuming the grounding of these cables is correctly done.

This pretty much leaves us with number 1. And you have already found your problem it would appear. Turning off or disconnecting the hot water tank is reducing 50 volts to 5 volts if I read you correctly......very high possibilty of a failing heater element as previously mentioned I believe. Not likely a hot to ground in the wiring compartment if the ground wire (egc) is terminated correctly.....if so your voltage would be closer to line voltage if somehow the pipes got energized. 

Next culprit is your well pump. When the pressure switch closes and water is pumped (the pump turns on..). When pump is off no shock...not necessarily in this order but lets just say the well pump can be a cause. I didn't go back in read if you get reduced voltage with the well pump circuit opened.

The voltage elevating as the other appliances are turned on with the water heater connected is an expected result of the added load to the system electrical. 

INPHASE 277 IS CORRECT

YOU MUST BOND THE *METAL* WATER PIPES to the *GROUNDED* conductor at the service equipment!!! So that a breaker will open if they get energized. 250.104 (1) specifically requires this and especially in this case where the pipes are plastic supplying the house (well supplied). If the pipes are metal as in 250.52 (A)(1) and 250.4 (A)(4)&(5) then you must run a water pipe bonding/grounding conductor from the pipe to the grounded conductor at the service equipment neutral bar or in some cases to the metal case (lug) of the service entrance enclosure. then you must supplement that with another grounding electrode.


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## tbwoods (Jul 6, 2009)

Thanks INPHASE277 AND STUBBIE and everyone else who helped here.

Is it hard to "bond" a system? I am fairly competant at electrical and mechanical work. Does this act as some form as ground fault?

Also, I remember one detail that I hope does not throw a curve ball here. I was in the well pit and my arm touched on a metal valve and I did feel a tingle there. I'm assuming that the electric heater issue could be sending current through the water in the plastic pipe. Or can this be a pump problem. .......... though the heater seemed to be a smoking gun? I don't believe the pump was running at the time but can't remember for certain.

Also, I called the water heater company and they say that no way can a water heater have a failure mode to cause such a problem. I don't believe that.


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## Stubbie (Jan 7, 2007)

FWIW 

I like to think of bonding as it relates to ground (earth) as the connection of a metal conductor..ie...to a grounding conductor (that is not part of a system circuit) that in turn is intentionally in contact with the earth via an electrode or whatever for grounding purposes. Bonding provides electrical continuity nothing more nothing less for whatever purpose is intended.

Using the term grounded to me means connected to earth or connected/bonded to a conductive material that is intentionally connected to earth. So grounded and grounding to me are basically the same thing as far as the NEC is concerned.

*Grounded Conductor* is a system or circuit conductor that is intentionally grounded (earthed).

Connecting or bonding a circuit conductor to the service grounded conductor makes it a grounded intentional current carrying conductor or grounded leg or neutral.

A non circuit conductor that is connected to earth even though it is bonded to the service grounded conductor like a grounding conductor of the electrode system is simply grounded or earthed. It is not a 'grounded conductor'.

The equipment grounding conductor is oddly named IMO ...


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## InPhase277 (Feb 9, 2008)

I have seen water heater elements with the casing around the actual resistance wire corroded away. Once that happens current can leak from the element to the water, and then to the plumbing. Turn the power off to the heater, remove the cover plates from the element areas, and disconnect the two wires that go to the element. With your meter set to the ohms or continuity setting, test between the two connection screws. A 4500 watt element should read somewhere between 10 and 15 ohms. Then check each between each connection screw and the plumbing metal. A good element will read infinite. A bad element will have a high reading, meaning a conductive path from the element to the plumbing through the water. You have two elements to test, usually.

What you should do, after replacing any defective elements, is jump the hot and cold pipes together with a couple of ground clamps (see attached pic), and continue the wire on to the panel ground/neutral bus. Do this with the main breaker turned OFF, and STAND TO THE SIDE when you turn it back on! A continuous piece of #4 copper, bare or insulated, is what I would use. Here is a pic of a typical ground clamp used on pipes:


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## Stubbie (Jan 7, 2007)

tbwoods said:


> Thanks INPHASE277 AND STUBBIE and everyone else who helped here.
> 
> Is it hard to "bond" a system? I am fairly competant at electrical and mechanical work. Does this act as some form as ground fault?
> 
> ...


Thats what a manufacturer is going to say everytime... A heating element is no more than a resistive material with voltage pushing current through it to create heat. It is part of the electrical circuit. If it cracks or deteriorates it can and will to a degree energize the water causing a voltage potential on the metal pipes and shower fixtures. This potential will not be the same as the system electrical and you will get shocked. Bonding properly will equalize normal voltages to below touch potential. But you need to find the source of this unwanted voltage and current (yours is way out of range). Do not mask it by trying to bond the water pipes to make it unnoticeable. You do need to bond them though....

The tingle in your water pump plumbing valve could have several causes I'd focus on the water heater first. See if that solves your problem with the shower then move to the pump and get some measurements. You can test the element/elements for their resistance but I'd just replace them.

INPHASE answered your other questions.....


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## 220/221 (Oct 9, 2007)

I have seen and repaired this problem more than once.

Generally it is an open neutral somewhere is the culprit. The 120v current is not able to return thru the neutral so it takes another path, thru the bonding/bootlegged ground or whatever is available..


OK...I read more of your posts and the problem appears to be in the *service conductor neutral* (wire/connectios or lugs)

The power isn't able to "return" on the compromised neutral so it seeks an alternative path thru your bonded piping, ground rods or ufer.

The more 120V load you add, the higher the voltage gets.

Bonding the piping systems is required but can result in dangerous situations when a service neutral fails.


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## tbwoods (Jul 6, 2009)

Thanks again to all. I will follow up on these suggestions an see where this takes me. 

Stubbie - Is bonding a difficult task?

I'll check the neutrals too. Good point 220/221.


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## InPhase277 (Feb 9, 2008)

tbwoods said:


> Thanks again to all. I will follow up on these suggestions an see where this takes me.
> 
> Stubbie - Is bonding a difficult task?
> 
> I'll check the neutrals too. Good point 220/221.


While 220 has brought up a situation that can occur, in your case it is very unlikely, because you would have symptoms such as some lights getting very bright, while others going very dim when you, say, started up the clothes dryer or turned the oven on. 

Is bonding a difficult task? Well, you said your panel and water heater are near each other, so not likely. It is far more difficult to understand than it is to do. See the second paragraph in post #23.


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## Bigplanz (Apr 10, 2009)

This is not a DIY problem. If you get a shock in the bathroom call an electrician immediately. DO NOT use anything in the bathroom until a professional has checked it out and repaired it. This is a potentially fatal shock situation. Get it fixed by somebody who knows what he or she is doing.


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## Yoyizit (Jul 11, 2008)

http://www.google.com/search?client=safari&rls=en-us&q=kbr+shower&ie=UTF-8&oe=UTF-8


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## kbsparky (Sep 11, 2008)

I'd call in the power company and have them check all their connections back to the main pole with the transformer attached. OR pad mount, which ever the case may be.

A bad "concentric" can cause the symptoms you described here, which is the high-voltage "neutral" connection on the primary side of the utility transformer.

Anything from a loose or burned connection to a bad neutral conductor in the main SE cable can be suspect.


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## Yoyizit (Jul 11, 2008)

kbsparky said:


> A bad "concentric" can cause the symptoms you described here, which is the high-voltage "neutral" connection on the primary side of the utility transformer.


"Transformer interwinding insulation construction which comprises a plurality of concentric spaced cylinders of insulating pressboard"

http://books.google.com/books?id=pa...yQme0I&sa=X&oi=book_result&ct=result&resnum=2

?


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## Red Squirrel (Jun 29, 2009)

Hey look on the bright side, I'm sure it wakes you up very well in the morning! :laughing:


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## kbsparky (Sep 11, 2008)

Concentric also refers to the outer conductor of [URL="http://uat.staging.exeloncorp.com/NR/rdonlyres/DF69C655-2087-402D-9C44-A77313386C7B/0/11_Cable_Specs.pdf"]medium Voltage cable,[/URL] which is commonly used by utilities to feed their step-down transformers. :whistling2:


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## InPhase277 (Feb 9, 2008)

What is it with the damn duplicate posts.. deleted.


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## InPhase277 (Feb 9, 2008)

It may be the neutral, but in every case that I have seen of a lost neutral, the primary symptom is some lights going bright and others dimming when a high-draw appliance is turned on. Being that the only connection to the earth from the shower drain is through water in plastic pipes, it seems like *Kirchoff's law *would dictate that if there is any noticeable voltage present at that connection, there MUST be lights blinking and dimming all over the place IF the service neutral is open.

If the OP hasn't noticed that symptom, then it is almost certain the service neutral is intact.


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## kbsparky (Sep 11, 2008)

All the more reason for the POCO to check their primary connections.


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## Stubbie (Jan 7, 2007)

Anything is possible and I see no problem with having the power company check out the primary side of the transformer because it is often the source of neural to earth current. For those who may not be aware of it the primary neutral is connected to the secondary neutral in most transformers that are not isolation transformers and they share the center tap grounding conductor to the ground rod. There has been lots of discussion about this being changed. If the source is the primary neutral the poco will install a isolator device to stop the NEV. Other than what inphase said... my problem with it being NEV from the utility is there is no connection to earth with any grounding conductor to the metal water pipes in the home...he says the pipes are metal once the plastic pipes from the well enter the home and that the pipes are not bonded to the service neutral. My opinion also is that if it was NEV he would not be losing 45 volts by disconnecting the water heater branch circuit. 

But we are not there so assumptions abound with any advice we may give.... so I do agree with KBsparky to have the power company check their stuff.

A current measurement on the grounding conductor to the ground rod that exists would be interesting to know with the main opened.

I'm not sure if NEV (STRAY VOLTAGE) could use the water in the well and pipes to produce the shocks in the shower but I would say it is possible and some plumbers swear that it will. I'd certainly have it checked out by the poco.


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## Stubbie (Jan 7, 2007)

Maybe he should bond the well water ....heck the NEC is now requiring you to bond your pool water....

I'll just say to the OP that you can quickly get overwhelmed as a DIY to solve a problem like you or having if it cannot be corrected as inphase has already said and someone with more experience needs to be contacted. Having the poco confirm (as kbsparky suggests) that there is no NEV or primary/secondary neutral problems will go a long way in your peace of mind.


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## tbwoods (Jul 6, 2009)

Thanks to all. I'm calling the power company today to get them to look at this.


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## Han'D' (Apr 7, 2009)

jbberns said:


> Your water lines should not be grounded. Even if your lines in the house are copper. I'd say that is your problem. Ran into a problem like this a few years back. Only they had replace a small section of pipe outside with plastic. Took a lot of head scratching. They were getting shocked everytime they were in the shower and the phone rang.


The thought of someone getting a shock when the phone rang was too funny! Thanx for that:thumbup:


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## tbwoods (Jul 6, 2009)

The electric company came by today and said everything was O.K. on their side.

I have an electrician coming over tonight but have a quick question.

This electricians first response was to say to connect the water pipes to the supply ground. Also check the water heater elements. He will check things over then we will go from there. But I have a quick question.

Stubbie answered in post 20 "you must bond the metal water pipes to grounded conductor at the service equipment!!! So that a breaker will open if they get energized." 

?? Is the reference to a "circuit breaker" above meaning any of the current breakers in my electric box, or is this a separate breaker added in the bonding process ?? 

I just want to be knowedgable when I meet with the electrician tonight.

Thanks in advance.


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## InPhase277 (Feb 9, 2008)

tbwoods said:


> The electric company came by today and said everything was O.K. on their side.
> 
> I have an electrician coming over tonight but have a quick question.
> 
> ...


No, it means that the metal water pipes must be bonded to the neutral at the service. In layman's terms, this would simply be called grounding the water line at the panel. What Stubbie's reference meant is that we ground the pipes so that if they are contacted by a live wire, there will be a circuit completed, and the breaker for the offending circuit will trip.

What the electrician will do is likely nothing more than what I describe in post #23.


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## Scuba_Dave (Jan 16, 2009)

jbberns said:


> They were getting shocked everytime they were in the shower and the phone rang.





Han'D' said:


> The thought of someone getting a shock when the phone rang was too funny! :thumbup:


 
*Can you hear me NOW ?? :laughing:*


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## tbwoods (Jul 6, 2009)

Thanks InPhase277. I should know tonight what is going on and if this does the job.:thumbsup:


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## spark plug (May 5, 2009)

*Definition of GROUNDED and GROUNDING*



Stubbie said:


> FWIW
> 
> I like to think of bonding as it relates to ground (earth) as the connection of a metal conductor..ie...to a grounding conductor (that is not part of a system circuit) that in turn is intentionally in contact with the earth via an electrode or whatever for grounding purposes. Bonding provides electrical continuity nothing more nothing less for whatever purpose is intended.
> 
> ...


Grounded you defined 95%! GROUNDING conductor, as defined by the NEC is one that EFFECTS grounding (i.e the conductor from the Service panel to the Grounding rod!


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## tbwoods (Jul 6, 2009)

I met with the electrician yesterday.

With all the power cut and meter pulled from the socket, we were getting 1.2 volts from the shower floor drain to the shower faucet. Based on this reading, he strongly believes that there is voltage entering the place from the outside and through the drain. I have no outside electric connected to the house at that point. even disconnected the phone line. He feels strongly about this. And he said not to worry about messing with water heater elements or bonding at this point. I visually checked and the system is definately not bonded. I have continuity between shower faucet elec box common though and no voltage difference between them.

My underground service and septic drain run parallel to each other within a foot or so of each other but I don't know the depth difference of each. He's thinking I might be getting voltage induced into the sewage line by the main feed or that I may be getting electricity from another outside source or perhaps another home about 50 yards away, traveling through the earth. 

He was going to have the elec company disconnect my service from the transformer to rull out the idea of the service line inducing voltage into the sewer line.

I'm working with him but am thinking of just going ahead with the bonding and heater elements though want to let him run through his troubleshooting process. 

Does any of this make sense???


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## InPhase277 (Feb 9, 2008)

1.2 volts will appear out of thin air. Based on the fact that 50 V appears when the power to your house is connected, and goes down to 1.2 V when the power AT your house if off, you can say with 99.999% certainty that the problem is at your house. Anything less than about 10 V is un-noticeable to the average human, unless it is on your tongue, or some other highly sensitive part of your body.

Very rarely would I say this, due to the fact the he is there and I am here, but he is dead wrong. How long does he recommend you wait before fixing the real problem? When it escalates to a fatal situation? There have been several soldiers killed in Iraq by this very same problem while taking a shower. Your problem can get worse, don't think it can't.

You can also try the very bad idea of trying to take a shower with the power off and seeing if you still feel the shock. I say bad idea because it's never a good idea to try and get shocked. I say change the elements, bond the piping, and be done and safe. He's trying to rack up some billable service hours by making several trips. Call someone else for a third opinion.


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## Yoyizit (Jul 11, 2008)

tbwoods said:


> we were getting 1.2 volts from the shower floor drain to the shower faucet.


If you can post overhead view diagrams showing all the "main characters" and where they are, and schematics for what you believe is your setup, and summarize what you tried and what result you had, we can all probably say what is possible, what is not, and what is likely.

That other thread about someone getting shocked while climbing out of a swimming pool led me to a link concerning water, skin area, current flow, etc.

You can simulate your body resistance with a resistor, from Radio Shack or wherever, and weed out phantom voltages. You want at least ~8 mA through this resistor because that's how much current it takes at 60 Hz to feel a shock through the skin. 

If the voltage that caused the shock was 50v you'd need 6.2k at 1/2w. 
If it was 5v, then use 620 ohms at any wattage. 
If the voltage drops when you hook up the resistor, this drop tells something about the impedance of the source. Current traveling through the ground will not have zero source impedance.

I use a "resistance substitution box" for these kind of tests, because it's hard to know ahead of time what value will give your 8 mA.

Once you've settled on a value, you can safely test different fixes.

And don't disconnect and reconnect possible sources; this assumes only one fault is present. Disconnect until the symptom disappears and then reconnect, one source at a time.


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## 220/221 (Oct 9, 2007)

I agree that the 1.2 volts probably mean nothing. I have read low voltage like this on disconnected wiring.


On typical equipment that we use, phantom voltage seems common.

I'd start turning stuff on until I at least read a _few_ volts


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## tbwoods (Jul 6, 2009)

I agree. No one has used the place since the original day the problem surfaced since it is a 2nd place. I'm heading over there tonight to install the bond and replace the elements.


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## tbwoods (Jul 6, 2009)

FYI - The day I discovered the problem, I read about 3.5 volts between floor drain and shower plumbing fixtures with the main breaker shut off and meter pulled.


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## jbberns (Jul 1, 2009)

InPhase277 said:


> 1.2 volts will appear out of thin air. Based on the fact that 50 V appears when the power to your house is connected, and goes down to 1.2 V when the power AT your house if off, you can say with 99.999% certainty that the problem is at your house. Anything less than about 10 V is un-noticeable to the average human, unless it is on your tongue, or some other highly sensitive part of your body.
> 
> Very rarely would I say this, due to the fact the he is there and I am here, but he is dead wrong. How long does he recommend you wait before fixing the real problem? When it escalates to a fatal situation? There have been several soldiers killed in Iraq by this very same problem while taking a shower. Your problem can get worse, don't think it can't.
> 
> You can also try the very bad idea of trying to take a shower with the power off and seeing if you still feel the shock. I say bad idea because it's never a good idea to try and get shocked. I say change the elements, bond the piping, and be done and safe. He's trying to rack up some billable service hours by making several trips. Call someone else for a third opinion.


Inphase makes the most sense to me. I would think it highly unlikely induced voltage travel up your drain line. Too much in the way. Like the plastic pipe and some dirt. I'd get another electrician for a different opinion.


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## Yoyizit (Jul 11, 2008)

Wet skin shock tester

basic parts list:
AC milliammeter set on the 200 mA scale
fast blow fuse, 1/4 amp
100 ohm 2w resistor.
Wire these three items in series.

additional parts and procedure:
Add a 30k, 1w resistor in series with the above and substitute this tester for the person getting shocked: if you read 4 mA or more you'll be getting a shock. Find the problem.
This assumes a 120vac source through some impedance is giving you the shock.

If you read less than 4 mA, replace the 30k resistor with a 3k resistor (any wattage): if you then read 4 mA or more you'll be getting a shock. Find the problem.
This assumes a 10vac source through some impedance is giving you the shock.

If you read less than 4 mA, connect directly to the 100 ohm, 2w resistor: if you then read 4 mA or more you'll be getting a shock. Find the problem.
This assumes a 0.4vac source through some impedance is giving you the shock.


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## spark plug (May 5, 2009)

*attempts at solving "Shocking" problem*



InPhase277 said:


> 1.2 volts will appear out of thin air. Based on the fact that 50 V appears when the power to your house is connected, and goes down to 1.2 V when the power AT your house if off, you can say with 99.999% certainty that the problem is at your house. Anything less than about 10 V is un-noticeable to the average human, unless it is on your tongue, or some other highly sensitive part of your body.
> 
> Very rarely would I say this, due to the fact the he is there and I am here, but he is dead wrong. How long does he recommend you wait before fixing the real problem? When it escalates to a fatal situation? There have been several soldiers killed in Iraq by this very same problem while taking a shower. Your problem can get worse, don't think it can't.
> 
> You can also try the very bad idea of trying to take a shower with the power off and seeing if you still feel the shock. I say bad idea because it's never a good idea to try and get shocked. I say change the elements, bond the piping, and be done and safe. He's trying to rack up some billable service hours by making several trips. Call someone else for a third opinion.


Beside the other possibilities, (Service entrance, inducing voltage into sewer system, etc.) It's beyond me how a professional electrician can advise someone to refrain from bonding ALL the metal pipes, etc. to Ground.
Because, regardless of where the source of the low voltage potential difference is (The 50v. source has already been established), if the pipes would be bonded, the reading (metal to metal) would be )0 Volts!!! :furious::no::drinkon't Drink and Drive!!!


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## tbwoods (Jul 6, 2009)

Thanks again to all. looks like I'll be doing this tomorrow and I will report back. Yoyizit - I'll test for the shock too.


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## Yoyizit (Jul 11, 2008)

tbwoods said:


> Yoyizit - I'll test for the shock too.


Thanks; some additional clarifying notes are bolded, below.

Add a 30k, 1w resistor in series with the above and substitute this tester for the person getting shocked: if you read 4 mA or more you'll be getting a shock. Find the problem.
*This assumes a 120vac source through some low impedance, or 240v through 30k, is giving you the shock.
*
If you read less than 4 mA, replace the 30k resistor with a 3k resistor (any wattage): if you then read 4 mA or more you'll be getting a shock. Find the problem.
*This assumes a 12 vac source through some low impedance, or 120 vac through 27k, is giving you the shock.*

If you read less than 4 mA, connect directly to the 100 ohm, 2w resistor: if you then read 4 mA or more you'll be getting a shock. Find the problem.
*This assumes a 0.4vac source through some low impedance, or 4v through 1k, or 40v through 10k, is giving you the shock.

The impedance this shocking current is passing through could be resistive or capacitive.
*

I hope this allows you guys to zero in on the cause.


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## Yoyizit (Jul 11, 2008)

*Rev b, more thoughts. . .*

During your testing, measure the voltage first with a DMM, so at least you know the open-circuited source voltage. That way the skin resistance and source resistance are the only unknowns.

Less than 0.1 vac should never shock an adult.

120vac always gives at least some tingling to most people which implies the skin resistance @ 120vac is always 120k or less.

"I get 22 to 50 volts AC."
With a possible wet skin resistance of 100Ω to 15k, and 1 mA being a tingle and >4 mA being serious, your skin plus source resistance must have been around 22v/(>4 mA) = <6k, or 50v/(>4 mA) = <13k.

Nobody got the 20 mA jolt, so your wet skin resistance, with your contact surface area, etc., must have been >3k.

"the voltage drops to 4 or 5 volts between shower plumbing and floor drain."
Assuming the same skin + source resistance, 5v/5500 = ~ 1mA and you might feel a tingle, or with 13k you'd feel nothing. 

But, note that because of the changes you made from the first voltage to the second voltage, the source impedance may have gone up or down.

So at least we have a handle on your wet skin resistance. The simplified test fixture is then a 200 mA AC milliammeter, the fuse, a 3k, and a 13 k resistor, assuming zero source impedance.

You should measure the source impedances of these voltages. That's another post.


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## tbwoods (Jul 6, 2009)

O.K. here is an update.
We can not simulate the high voltage measurement between the drain and shower faucet not matter what I turn on in the house. I can only get 1 volt. This is before doing nothing at all.

But the electric company had come out to check my feed to the house and said everything was O.K.. .. They could not find anything wrong. But since they came out, I can not duplicate the problem.

So I had them out again. They determined that they had about 1.2 volts comming in on the large ground wire and this was problem on their end. They could not run the problem down so they installed a "neutral isolator" 0n the transformer. By the way, there are 2 other houses that share the same transformer.

After installing the neutral isolator, the voltage drops down to .10 volts.

I changed the water heater elements anyway (even though they checked good with a meter) and bonded the water pipes. 

It bothers me that I could not reconstruct the problem then verify the remedy.

I checked with the 2 neighbors. We were theorizing that they may have a faulty appliance or wiring and backfeeding through the neutral which the 3 homes share. We turned every appliance on at my 1 neighbor and saw no spike in voltage between their ground bar in the box and earth and I checked my shower and likewise saw not increase beyond .10 volts. 

My other neighbor has not been at their place for a month and we could not turn on their equipment. Their meter was not spinning at all and I know they were not at their place at the time I had our high voltage reading. so I think we ruled out the problem from a neighbor.

So this where I am now. I wish I had a smoking gun but do not.

I have a question. It seems that bonding (since I have plastic pipe coming into the house from the well and all copper inside) will just cause electricity to feed into my plumbing if there is a problem from the outside. Or is a copper ground so efficient that the path of least resistance will be to ground versus through the water in the shower?

Anyone have further thoughts on this????


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## 220/221 (Oct 9, 2007)

> Anyone have further thoughts on this????


I hate when that happens.

It's tough to fix if it aint broke.


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## Stubbie (Jan 7, 2007)

> I have a question. It seems that bonding (since I have plastic pipe coming into the house from the well and all copper inside) will just cause electricity to feed into my plumbing if there is a problem from the outside. Or is a copper ground so efficient that the path of least resistance will be to ground versus through the water in the shower?



A common misconception. It's current that enters your house. It always seeks its source which will be the transformer not ground (earth). It will take the lowest impedance path to get there. So if it flows in over your grounding electrode conductors it will take the service neutral back to the transformer center tap. 
However current entering your house from outside is not good but your power company says no and they installed a neutral isolator like I mentioned in an earlier thread. This is why I wanted a current reading on your ground rod grounding conductor. 
Current can potentially energize your water pipes because of the bonding but will likely never be a problem unless your service neutral opens/fails. Which is the path current takes to get back to the transformer. Bonding the metal pipes is much better for safety than not bonding them and having that huge potential difference sitting there for voltage to energize if a hot wire should contact them. Not having a way back to the the source because the metal pipes are not bonded to the service neutral will bring the pipes to line voltage and if someone touches one your going to take a jolt. If they are bonded to the service neutral then if contacted by a live wire current will flow in such large amounts the breaker will trip that is protecting the branch circuit causing the fault. 

You might be interested in reading this thread that is on going currently to help you understand a few of the concepts we are talking about...

http://www.diychatroom.com/f18/tripping-breakers-neutrals-120-volts-240-volts-oh-my-49295/


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## spark plug (May 5, 2009)

As 220/221 said "It's tough to fix when it ain't broke". But Congrats. for bonding all the metal pipes to Ground. That did the trick. No matter what. There will not be a discernible potential difference between any metal pipe and ground. Don't Drink and Drive!!! (wish I could import some smilies to "Quick Reply"!!!


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## Yoyizit (Jul 11, 2008)

I'm always learning something on this forum. . .
http://www.dairyland.com/media/products_vtni_technical_literature.pdf


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## tbwoods (Jul 6, 2009)

Any thoughts on my question from above ........................

"I have a question. It seems that bonding (since I have plastic pipe coming into the house from the well and all copper inside) will just cause electricity to feed into my plumbing if there is a problem from the outside. Or is a copper ground so efficient that the path of least resistance will be to ground versus through the water in the shower?

Anyone have further thoughts on this???? "

I realize that since I have an electric water heater that my plumbing was already tied to my ground.
Another thing that still bothers me is that i could never see the high voltage again after the elec company visited me the 1st time and said they found nothing. The 2nd time they installed the neutral isolator. I'm not saying they are not being truthful. Just am puzzled why I never saw the high voltage again ..... I may never know.


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## InPhase277 (Feb 9, 2008)

tbwoods said:


> Any thoughts on my question from above ........................
> 
> "I have a question. It seems that bonding (since I have plastic pipe coming into the house from the well and all copper inside) will just cause electricity to feed into my plumbing if there is a problem from the outside. Or is a copper ground so efficient that the path of least resistance will be to ground versus through the water in the shower?
> 
> ...



I believe Stubbie addressed this above. But I will add that it may be a coincidence with the power company, or the act of troubleshooting may have removed the problem without anyone knowing.

If it was the heater, it may have just reached a point in its failure that actually removed the fault. Bonding your plumbing does tie it to the electrical system. But this is a good thing, because if a hot wire or faulty appliance (water heater) directly energizes the pipes, a breaker will trip. If it is indirect through a resistance, the current will take the least resistive path and avoid unlucky people in the way.

Unbonded pipes lead to your problem, or worse. If a hot wire had directly energized the pipes while ungrounded, it would have just sat there waiting for a path, and this may have been through somebody.


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## Stubbie (Jan 7, 2007)

tbwoods said:


> Any thoughts on my question from above ........................
> 
> "I have a question. It seems that bonding (since I have plastic pipe coming into the house from the well and all copper inside) will just cause electricity to feed into my plumbing if there is a problem from the outside. Or is a copper ground so efficient that the path of least resistance will be to ground versus through the water in the shower?
> 
> ...



Part of the problem is chasing voltage. Voltage can be a odd thing to track down as many times it is just phantom. Digital voltmeters read phantom voltages all the time and voltages much higher than 50 are not uncommon. In your case you were reading a voltage from the plumbing of the shower to a metal drain cap that was connected to a plastic drain. So essentially you were seeing the potential difference between the metal drain cap and the metal plumbing. Imo this was due to the pipes not being bonded. Since there was no conductive path that we know of that current could flow from the plumbing to the drain.... a better way to have checked the plumbing would have been to extend a ground into the shower so that you could check the plumbing to a known return path to the transformer. I'm not sure you or the electrician made that measurement. At 50 volts and using a digital voltmeter (unless you were using an analog type) wouldn't necessarily alarm me until I investigated further. The problem I saw was that you say you were actually feeling a shock which tells me you had a current flow. Which led to us being concerned about your water heater. But it is the current that is a more important indicator of a serious problem. So what I would like to have seen was a good return path to the transformer connected to that plumbing. And then a current reading on that return path. You have done that now with the bonding. But it is important that you bonded correctly by bonding both hot and cold together then extending that bond to the neutral bar of the main service equipment panel. If you have done that any *real* unwanted voltage from some electrical source will show its ugly face with current flowing to the transformer on that bonding wire to the panel neutral bar. You might put a clamp on meter around that bonding wire and see what you have as to current. If you bonded correctly and no breakers tripped then you certainly don't have a line voltage problem from the metal plumbing and a live wire...so the next issue is neutral current either inside or outside sourced. the breaker can't see that current. I doubt that it is outside as the POCO seems to have done there thing to prevent it. None the less you are not getting shocked any more after bonding the pipes assuming it was done correctly. I would simply make sure you do not have current on that bonding conductor for your water pipes.
I know this has been frustrating and the problems you originally found can be very elusive and no 'smoking gun' other than no bond to the metal pipes has been discovered.


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