Electrocuting water tanks

It has been quite some time but I know this was discussed at some point. I have a stock tank heater that is putting volts into the water. I ran a 100 foot cord from the shed to this pen last year but it was just one boar so I used a heated bucket. The element doesn't touch the water. I never had any issues.

This year I have some feeder pigs in that pen. I threw in one of those 75 gallon recycled tire stock tanks and they have been using it all fall. I put in a brand new stock tank heater and it is shocking them. Not like electric fence level but enough to make them jump. I can tell you that the ground prong is part of it because when I unplugged the heater one came and drank. While he was drinking I plugged in just the ground prong into the cord and he got shocked. It isn't much, but I am getting residual from somewhere.

Do I test across the prongs of the tank heater or from the water to the ground? I thought it was odd when everyone was talking about it years ago, but I remember JD Seller saying something about driving in a ground rod next to each tank. Do I do that and then run the other end into the water?

What do I test to determine the fault and how do I fix it?

Rubber tank is hard to ground. This might sound weird but the extension cord might be the problem. Extension cords are usually for "temporary indoor use". take a piece of UF 12-2 Romex and install a WP box on a post and use a GFI. Extension cords and moisture don't mix.

You should not have any voltage on the ground. I'd start with a qualified electrician- it sounds like you may have a significant problem, and if it is due to the power company, you will need a reference from your electrician.

It may cost some money, but dead or poor performing livestock costs more.

4020 electrician brings up a good point.

Notjustair,It sounds like the cord could be bad or have a cut,ground wire touching the hot wire, or something.Check the cord with a ohm meter.Also check the outlet with a volt meter,Hot,common and ground lugs.

I would get a volt meter and see what kind of voltage you have on the ground circuit. You probably have a bad device somewhere else on the system (could be the extension cord as others have said, but it could be another heater, a light circuit, or something else). Driving a ground rod may just cause you to trip a breaker or blow a fuse. You need to track down where current is getting into the ground, and I would bet that the ground at the pen is not continuous back to your breaker panel. You may have a perfectly good wire with a corroded ground connection which was burned when the defective device failed, creating an open circuit in the ground. Until you track it down, all other parts of that circuit are not safe. Do you have any triplex aluminum (old overhead service) as part of your distribution system? If you do I'd check it out first. The quick solution is to cut the ground prong off the tank heater so it does not get the feedback, but of course that would not meet any code or safety requirements.

I agree with 4020 electrician, and all outside outlets should be on GFCI.

Is it possible that the ground is getting voltage by inductance with a bad connection to ground at the feed end of the cord? Electrical engineers or electricians might chime in and say whether or not I am full of hot air.

SJOW cord is rated for outdoor use, but it isn't often what the cheap cords are made of.

(quoted from post at 16:18:02 01/01/16) Is it possible that the ground is getting voltage by inductance with a bad connection to ground at the feed end of the cord? Electrical engineers or electricians might chime in and say whether or not I am full of hot air.

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I'd hate to throw cold water on your bad connection idea, shocking, isn't it? Actually it could be induced voltage if the other end of the of the cord is not grounded and the cord is coiled. But that voltage would stop when there is no current flow through the heater element.

The induced voltage theory is interesting, but I am not sold on that, the current between the neutral and hot should cancel an induced voltage when run together.

A bad cord will immediately trip a gfi. If you have no meter to test between conductors of the cord just plug it into a gfi in the house to test it. It will detect continuity between ground and neutral and trip. No load required.

I have seen things short out because on a replacement plug one of the small wires from under the hot screw was touching the ground screw, Not enough to trip a breaker, just enough to let you know.

Let me put on my olddddddddd rusty electrical enginners hat and think this through.

If its a rubber tank that doesnt seem to be the problem nor is it like a conductive metal tank you can bond to the Equipment Grounding Conductor.

If porky pig feels a shock when he's standing barefoot on wet ground and touches the water in which the tank heater is somehow somewhere in contact THE HEATER OR CORD COULD BE SOMEHOW DEFECTIVE AND THE WATER IS ACHIEVING A HIGHER VOLTAGE POTENTIAL THEN MOTHER EARTH. IE VOLTAGE BETWEEN WATER AND EARTH ON WHICH PORKY IS STANDING OUCHHHHHHHHHHHH LOL

Heres another possibility. When you run a Hot and a Neutral and an Equipment Ground out to the barn due to the wires being in parallel, mutual inductance and capacitance can cause the Equipment Ground to out there be at a voltage potential higher then mother earth. Livestock are super sensitive to small voltage potential and can feel a shock especially since they are bad about standing barefoot on wet ground lol. Best I recall the NEC has a special exemption for buildings used to house livestock in that out at the barn they allow the equipment ground to be re bonded to earth in order to bring it back down to earths potential so bossy or porky don't get a shock.

However if you use a GFCI to power the heater and it or the cord is defective or its poorly designed SURE THE GFCI WILL PREVENT A SHOCK BUT IT WONT STAY ON TO POWER THE HEATER EITHER!!!!1111 I'm a believer in and the NEC requires GFCI for outdoor applications BUT IF THE HEATER OR CORD IS BAD IT WONT ALLOW IT TO WORK SO IS NOTTTTTTTTTTTT THE ANSWER, THE ANSWER IS TO CURE THE PROBLEM

Also, while the NEC has an exemption and a cure (re bond Equipment Ground to earth so its at same potential out at remote barn and the use of equal potential grids etc) for livestock buildings so they don't get shocked, THE SYSTEM IS NOTTTTTTTTTTT FOR BILLY BOB AND BUBBA TO GO AROUND DRIVING RODS IN THE GROUND ATTACHDED TO WATER TANKS!!!! Sure it may tend to work but its certainly NOT any proper or NEC approved method and could even become a hazard GO AHEAD AND DO IT AT YOUR OWN RISK IS FINE BY ME HOWEVER

I would have a professional inspect and test and measure the heater and cords and if they are okay look into the NEC exemptions for re earth bonding the ground at the buildings and/or the use of equal potential earth grids.

Maybe just A BAd heater or cord,,,,,,,,,GFCI if it works may then not allow the heater to work,,,,,,,,,,be careful about home made remedies like going around driving ground rods if you don't know what youre doing,,,,,,,,,,,,if all else checks fine then you have to look at the NEC grounding remedies for livestock buildings

John T NO WARRANTY its been years since I practiced engineering this may be wrong as rain, consult a trained professional is my advice or else do as non trained Billy Bob and Bubba think

It won't be induced voltage . It is a ground conductor elevatated above true earth potential because there is neutral current flowing in the grounding system.
Is the receptacle midwired, barn wiring misswired ? Is there a 120V load returning neutral current through the ground system?
Or the ground system is elevated because it's not making good contact with "earth" .and the bond to neutral at the utility meter is raising the ground system because the neutral has a lot of voltage drop on it.
How is the power sent to the barn? Overhead triplex or underground with two live lines, a white insulated neutral and a green or bare ground ?

Since you are using a 100 ft cord I assume the shed where the pigs are does not have electricity. Correct? If the shed does have outlets you may want to inspect them for damage from moisture and dust accumulations.

These kind of issues can be tough. My neighbor wanted me to help him fix some lighting in his horse barn. Long story short as I was fixing the lights I was getting voltage where it should not be. An outlet had shorted internally, overheated, and was putting voltage where it should not be.

1. Even though new, the heater could be bad. Have you tried it at a different location, e.g. a different outlet.
2. Have you tried replacing the cord.
3. Have you investigated the outlet the cord was plugged into. Also, you can get outlet testers at Menards, etc. Some will also test your GFCI.
4. Once you can measure the voltage on your ground, you should be able to backtrack to where it is coming from. It may require separating out circuits.
5. If you are uncomfortable with all this you should get an electrician.

Paul

The first thing I would test is the ground part of the outlet. You may be getting a back feed on the ground wire, making it have a floating voltage on it. Then replace the cord and check the heater, just because it is new doesen't mean it is not at falt. Some thing else you can do is turn off all other breakers in that panel not feeding the heater. And watch the pigs. You have a problem that needs a good troubleshooter. Please let us know what was the problem. joe

In the event the heater and cord check out fine and theres no shock if the equipment ground is removed, it could be as I described below the Ground out there has achieved a voltage higher then mother earth at the barn. Billy Bob or Bubba may drive ground rods right at the tank and bond the equipment ground to earth which may temporarily cure the shock but that's NOT the proper or safest or NEC method HEY DO IT IF YOU LIKE,,,,,,,, REMOVE THE GROUND ORRRRRRRRRR BOND IT TO EARTH !!!!!!!!!!!!!!!!!!!!!!!! but NoT my advice of record lol

Its also very common for Billy Bob or Bubba to have mixed up and crossed and reverse wired the Hot and Neutral in the panel or cords or plugs or receptacles!!!!!!!!!!!!!!!!!! THAT MAY WELL ALSO BE THE WHOLE PROBLEM IE MIS WIRING !!!!!!!!!!!!!

Incorrect or crossed or reversed wires,,,,,,,,,,,bad heater or cords,,,,,,,,,,,,ground has elevated potential,,,,,,,,,,BUT GFCI ISNT THE ANSWER FOR ALL THAT LOL nor are home remedies

John T

Take the heater back to the store no good! To test it put a metal spoon on each volt meter lead, and put one into the soil at the base of the tank, and one into the water. plug it in. if even one volt, the dang thing is bad. Jim

I realize there are rated cords. But "usually" people don't make 100' SO or SJO cords because of cost. I'm willing to bet it's a 16/3 extension cord.

And put them on a GFCI !!!.

Do yourself a favor and run the right wire out by the tank and GFI the circuit. We do it all the time on water tanks on new or existing Dairys. If we get a "Frozen" tank call guess what... 9 out of 10 times the farmer shut the breaker off in the spring and forgot to turn it on. Get rid of the cord as much as possible.

4020 offers a good description of how to do this right, run the UF cable to a GFCI outlet with an IN-USE weather proof cover. You can use buried PVC conduit and THHW or XHHW-2 insulated wire instead of the UF cable if you want.

Couple of other things. Is this plugged in to a GFCI outlet? GFCI works by measuring current (amps) out and current back, if they differ by more than about 5 milliamps, it trips. If you are tripping a GFCI, it means you have a leakage current, which means part of your insulation is likely compromised. Time to replace.

If it does not trip a GFCI, the next thing I would check is do you have a difference in ground potential between where you have your tank and where your electric service ground is. If so, the easiest way to correct this may be to just get a metal water tank. The metal tank will provide a bonding path between the water and the earth it is sitting on.

First though is get rid of the extension cord and do what 4020 electrician suggested. Hope this helps.

BTW, I am a registered electrical engineer.

Could be a bad heating element. I had a brand new heating element do this same thing in a hog water. It about drove me nuts. I tried multiple ground rods, everything I could think of but I finally replaced the brand new element with another new one and the problem was solved. The hogs would touch it and flinch. A few brave ones would drink but were jumpy as they drank. The element was a horseshoe shaped one that slid into clamps under the drinking trough. It was stupid simple to replace, a five minute job.

I don't think many people read the post clear thru. He stated that by just connecting the ground prong on the heater to the ground prong of the cord the problem has to be with the cord or the outlet it is plugged into NOT the heater, he has a hot ground conductor.

Start out at the outlet and use a volt meter between the ground lug hole and earth, should have no reading if you do work toward the breaker box, if no reading then sounds like trouble in the cord, check for any continuity between the ground and ether other conductor.

I had this issue some time back I was getting 3 to 9 volts between the water in the fount and earth. I finally tracked it to a broken neutral in the overhead triplex feeding the barn from the house.

I am not an electrician, but to my way of thinking you either have a bad cord, an outlet wired wrong, or some wiring messed up in a junction box which would give the same results as outlet wired wrong. You can get an outlet tester like this one for $5 to $10 at most any hardware or big box store.

Ya I re-read it and the post does say it tingles the hogs when only the ground prong is plugged in. Bubba would cut the ground prong off and use it. Out of sight, out of mind.

I wonder if there is juice following wet or damp cobwebs or junk in a box somewhere and ending up in a ground lug that is not bonded to earth. This part of the country has been pretty wet. Just a wild guess.

More fun then Saturday morning cartoons, as always electrical or legal questions draw more opinions then any other topic.

Just a GFCI 101 Technical Discussion for the non electricians and engineers out there for future reference:

The GFCI passes the Hot Ungrounded Conductor and the Neutral Grounded Conductor through a Torroidal coil. If allllllllllllll the outgoing hot current is returned via the Neutral (as it should) the electromagnetic induced voltage into the coil is canceled so theres no trip HOWEVER if some of the current is returned via a faulty leakage path (grounding conductor or a short or your body etc) and its around only 5 milliamps that's enough of an induced voltage signal to trip the GFCI. If a heater or other device were connected via a GFCI and there was indeed leakage current (like the equipment grounding conductor was returning some) it will trip and the heater wont work. IE use of a GFCI on a faulty circuit isn't the answer to the problem as it will open the circuit but NOT operate the heater YOU HAVE TO FIX THE PROBLEM then use of a GFCI is a good and safe thing plus NEC required in outdoor locations plus others.

If there a shock ONLY if the equipment grounding conductor is in place, there has to be a fault (heater or cord) or mis wiring or hot and neutral and ground are mixed or crossed somewhere or voltage is induced into the ground by which that conductor is energized at a potential higher then local mother earth so porky pig gets shocked OUCH.

HOWEVER which of those possible causes just cant be determined here over the internet by engineers or electricians or lay persons or Billy Bob SORRY

If you were to go back to the main distribution panel and insure a proper Neutral to earth bond and a ground to neutral bond and all was wired correct and there are no loose neutrals or grounds and no downstream re bond of Neutral and run a new dedicated circuit out and if applicable use the NEC livestock building rules and exceptions to bring the ground back down to earth potential AND THE HEATER AND CORDS ARENT FAULTY I bet that will cure the problem !!!!!!!!!!!!!!!!!!!!!!! I'm NOT in favor of home remedies like ground rods (attached to what and where???) or non NEC temporary band aid fixes that dont cure the actual cause and fault but do so if you please as some will stop the shock (but NOT cure the cause).

Nowwwwwwwwww as to which of the possible causes (heater, cord, mis wiring, loose connections, induced voltage, is the problem) HARD TO SAY BY ANYONE NOT BEING THERE

Yall keep safe now an d Happy New Year

John T too long retired EE and rusty but still believe the above holds true but NO warranty lol consult trained professional electricians or Billy Bobs at your own choice

John,

I would really make sure that the earth ground is working on the building and move out from there, the whole building could have an elevated ground and this is just where you see it.

What do you think?