Stock Tank Deicer grounding

[dieselcrawler]

Unless something goes really wrong electrocution is out of the question. However the horse being shocked slightly is not.

The problem is that the system ground bonds to neutral at the service box. There neutral is at ground and some small current flows between the two to keep it there. If the ground is very good it stays at true ZERO (impossible actually but verry close). If the quality of the ground degrades, such as in dry weather, the true zero will not be there and service box will be at that non zero ground -- perhaps a volt. The wires to your tanks run a solid wire taking that 1V potential directly to the body of the heater immersed in your horses water. The horse comes up, stomps down four ground rods establishing his true zero and pokes his mouth into water that is at a 1V potential. Fix it quick or itll be hard to undo the aversion therapy.​

We had our horses shying away from a 0.7V potential between the water and the horses grounded hooves. We fixed it by disconnecting service ground at the heater plug and connecting the ground prong directly to a ground rod driven in at the tank location.

Please never do that! Adding the extra ground to the existing ground wire would be fine. But disconnecting it can still allow the neutral wire to ground wire you added have a measurable voltage. You have made a more dangerous situation by disconnecting the original equipment ground. Adding to it, with another ground rod, is fine.

 

[SPYDERLK]

Please never do that! Adding the extra ground to the existing ground wire would be fine. But disconnecting it can still allow the neutral wire to ground wire you added have a measurable voltage. You have made a more dangerous situation by disconnecting the original equipment ground. Adding to it, with another ground rod, is fine.

It wouldnt work that way. The service ground held the local ground high. The only way I could get the water to local ground zero was to isolate the heater on a local ground. Neutral wires always have a small voltage relative to ground anyway when they are carrying current. At a 15A load location it could be a couple volts in a 12 Ga line.

 

[RNeumann]

Just to be clear, a deicer (at least the ones I’m thinking of) shouldn’t add any voltage to the water. If it does it’s either broke or defective.

 

[dieselcrawler]

Just to be clear, a deicer (at least the ones I’m thinking of) shouldn’t add any voltage to the water. If it does it’s either broke or defective.

Agreed

 

[buickanddeere]

Unless something goes really wrong electrocution is out of the question. However the horse being shocked slightly is not.

The problem is that the system ground bonds to neutral at the service box. There neutral is at ground and some small current flows between the two to keep it there. If the ground is very good it stays at true ZERO (impossible actually but verry close). If the quality of the ground degrades, such as in dry weather, the true zero will not be there and service box will be at that non zero ground -- perhaps a volt. The wires to your tanks run a solid wire taking that 1V potential directly to the body of the heater immersed in your horses water. The horse comes up, stomps down four ground rods establishing his true zero and pokes his mouth into water that is at a 1V potential. Fix it quick or itll be hard to undo the aversion therapy.​

We had our horses shying away from a 0.7V potential between the water and the horses grounded hooves. We fixed it by disconnecting service ground at the heater plug and connecting the ground prong directly to a ground rod driven in at the tank location.

This is why the only ground bond to the neutral is to be at the utility service . Not removing the bonding screw at sub panels or using overhead triplex is just looking for tingle voltage shocks to livestock.

 

[buickanddeere]

Please never do that! Adding the extra ground to the existing ground wire would be fine. But disconnecting it can still allow the neutral wire to ground wire you added have a measurable voltage. You have made a more dangerous situation by disconnecting the original equipment ground. Adding to it, with another ground rod, is fine.

Neutral is supposed to float free of ground everywhere on the consumer side of the service after the bond at the service .

 

[dieselcrawler]

Neutral is supposed to float free of ground everywhere on the consumer side of the service after the bond at the service .

Exactly, neutral and ground are only bonded at the service entrance equipment, but the way the posts read to me, we are talking about the equipment ground wire, not neutral wire.

 

[GregbkH]

We had our horses shying away from a 0.7V potential between the water and the horses grounded hooves. We fixed it by disconnecting service ground at the heater plug and connecting the ground prong directly to a ground rod driven in at the tank location.

I am also an electrician and am glad to see that others have warned you off of doing this "Fix". Disconnecting the equipment ground at the plug and attaching it to a ground rod with a conductor would be dangerous. If there were a ground fault the breaker may not trip at all in this configuration. The fault is trying to reach home (electrical panel) and now the fastest path to home has been taken away and put on a much slower path (ground rod) which may not get there in time if at all.

Bottom line is you are 100% safe and covered with the properly installed gfci receptacle.

 

[oosik]

When we had a horse, she WOULD NOT drink from the water trough - plastic - with the submerged tank heater installed. Removed the heater - broke the ice in the AM and again in the PM, every day. She drank then with no problems. The instructions for the tank heater gave no indications that any sort of extra grounding was required.

 

[TheMan419]

Installed new deicer today. We will see what that brings. Instructions do not specify additional ground rod. They specify properly installed gfci outlet.

Thanks all for the advice.