Hard-Wired Barn Water Trough Heaters - GFCI??

[Sharpie]

I have searched the NEC and this thread, and I cannot find where it is required (although I thought it was) to protect a Watering Trough Heater (Hard-Wired) with GFCI.

Is there a requirement or standard out there that anyone is aware of that would require this?

I am aware of Equipotential Plane requirements for concrete slabs.

Thanks,

 

[tom baker]

Did you look at 547.3?

 

[Sharpie]

Tom, I have looked at it, but I'm not sure how that helps me find what I'm looking for:

"547.3 Other Articles

For buildings and structures not having conditions as specified in 547.1, the electrical installations shall be made in accordance with the applicable articles in this Code."

 

[sparky=t]

tank / trough heaters

tank / trough heaters

most all manufactures instructions will call for GFCI protection, I would not install one with out it.

 

[kwired]

Did you look at 547.3?

"For buildings and structures not having conditions as specified in 547.1, the electrical installations shall be made in accordance with the applicable articles in this Code."

Well that would send us to 210.8 for general GFCI requirements since there is no requirement in 547. I don't see anything in 210.8 that would require it either. About only thing left is 110.3(B) which leads us to:

most all manufactures instructions will call for GFCI protection, I would not install one with out it.

I can't say I have ever seen any instructions for any of those, and have never connected one to a GFCI. I also have little concerns if connected to a proper equipment grounding conductor. All instances I have seen where animals were getting shocked were instances where improper equipment grounding was done.

With all the damp conditions in and around these things I can see class A GFCI being a constant trip problem, I would maybe be OK with 30ma EPD fault protection though.

 

[Sharpie]

That's what got me started on this search. The water heaters in a barn that I service were previously installed, and tripping is an issue.
I have isolated every part, used a multi-meter, and cannot find any ground-fault paths. It also takes a few minutes to trip as well.
Is there another type of testing I should be doing?

I cannot find any requirements for GFCI protection in the Manufacturer's instuctions. There are specific instructions on grounding & bonding.

Thanks everybody for your replies,

 

[Smart $]

Article 427 scope; Part III; specifically 427.22.

 

[kwired]

Article 427 scope; Part III; specifically 427.22.

I have never had art 427 cross my mind when working on these, but after reading through 427, I think it does apply.

That said I see other sections in 427 that are never applied to these installations as well. I am also willing to bet most of the units I have ever seen are not listed or those sections would likely already be in compliance with basic design of the unit.

Surprisingly though there doesn't seem to be all that much incident with those units either. If you have a unit with a "hot" enclosure cows feel voltage gradients as they approach - and generally just stay away. Pigs are too curious, you just find them dead around the water tank, but hardly anyone has outdoor swine operations anymore either so that doesn't happen either.

 

[Gregg Harris]

Looking back to NEC 2002

547.10 (B) began to address the GFCI in this situation.

Looking at 2011 577.10 (B) you have fine print notes that referencing ASABE Safety for Electrically Heated Livestock Waterers in the document "it is highly recommended to be installed using GFCI

 

[ActionDave]

That's what got me started on this search. The water heaters in a barn that I service were previously installed, and tripping is an issue.
I have isolated every part, used a multi-meter, and cannot find any ground-fault paths. It also takes a few minutes to trip as well.
Is there another type of testing I should be doing?

I cannot find any requirements for GFCI protection in the Manufacturer's instuctions. There are specific instructions on grounding & bonding.

Thanks everybody for your replies,

What kind of heaters are they, built into the trough or the ones that you drop in?

Are you testing them while they are hot?

 

[Sharpie]

The heaters are "U" shaped elements mounted to the bottom of the Stainless Steel water bowls. There is also a heat trace cable that goes down the piping. all of this is enclosed inside/ under the trough. The heating unit is controlled by a built in thermostat.

When I tested, it was de-energized.

 

[kwired]

What kind of heaters are they, built into the trough or the ones that you drop in?

Are you testing them while they are hot?

My experiences of testing them usually is with circuit energized, but circuit is not complete for some reason otherwise it would be working and I wouldn't be there in the extreme cold trying to find out why the unit is all froze up

Those first few cold nights in the fall they may get a little ice on them but often is not really noticed, it is when we get that first bone chilling cold weather when it finally gets cold enough to totally freeze the thing up is when you finally get the call to find out why it doesn't work. And it is somewhat of an emergency as those animals do need water fairly soon. The only good thing is all the mud, manure, etc in the vicinity is also frozen so it is not really all that messy at the time.

 

[ptonsparky]

My experiences of testing them usually is with circuit energized, but circuit is not complete for some reason otherwise it would be working and I wouldn't be there in the extreme cold trying to find out why the unit is all froze up

Those first few cold nights in the fall they may get a little ice on them but often is not really noticed, it is when we get that first bone chilling cold weather when it finally gets cold enough to totally freeze the thing up is when you finally get the call to find out why it doesn't work. And it is somewhat of an emergency as those animals do need water fairly soon. The only good thing is all the mud, manure, etc in the vicinity is also frozen so it is not really all that messy at the time.

Oh the memories of those good times. Had one of my all time favorite customers call me dead of night, colder than a witches..., pen full of hogs with no water. She had generator, large kerosene space heater and a foam pad for me to lay on while I worked. Something is always fresh and unfrozen in a hog lot. Plus she kept my boots from being eaten as I lay there.

I think my rate was $13 at the time.

 

[kwired]

Oh the memories of those good times. Had one of my all time favorite customers call me dead of night, colder than a witches..., pen full of hogs with no water. She had generator, large kerosene space heater and a foam pad for me to lay on while I worked. Something is always fresh and unfrozen in a hog lot. Plus she kept my boots from being eaten as I lay there.

I think my rate was $13 at the time.

That is one thing nice about the fact that most all hogs are raised in indoor facilities anymore. Many watering units designed for hogs were the worst to access in brutal cold conditions, as you often needed to thaw or chip away frozen matter just to get into them. Watering units for cattle sit high enough they generally don't have much of that trouble.

 

[ActionDave]

The only good thing is all the mud, manure, etc in the vicinity is also frozen so it is not really all that messy at the time.

No doubt!

Oh the memories of those good times. Had one of my all time favorite customers call me dead of night, colder than a witches..., pen full of hogs with no water. She had generator, large kerosene space heater and a foam pad for me to lay on while I worked. Something is always fresh and unfrozen in a hog lot. Plus she kept my boots from being eaten as I lay there.

I think my rate was $13 at the time.

You must have gotten a cup of coffee out of the deal too.

 

[ActionDave]

The heaters are "U" shaped elements mounted to the bottom of the Stainless Steel water bowls. There is also a heat trace cable that goes down the piping. all of this is enclosed inside/ under the trough. The heating unit is controlled by a built in thermostat.

When I tested, it was de-energized.

You need to check them out under load. By-pass the t-stat and check it out after you have ruled out the elements. Take half of the heaters off line and re-energize; repeat as needed. The only thing left after that is the feed.

 

[ptonsparky]

You need to check them out under load. By-pass the t-stat and check it out after you have ruled out the elements. Take half of the heaters off line and re-energize; repeat as needed. The only thing left after that is the feed.

Yes the, the thermostats. I have had those little round metal ones give grief.

 

[Sharpie]

I'll have to check that out. I have tried isolating the different parts, but I might have left the t-stat in line with them. I'll give that a shot.

Thanks,

 

[jap]

I have never had art 427 cross my mind when working on these, but after reading through 427, I think it does apply.

That said I see other sections in 427 that are never applied to these installations as well. I am also willing to bet most of the units I have ever seen are not listed or those sections would likely already be in compliance with basic design of the unit.

Surprisingly though there doesn't seem to be all that much incident with those units either. If you have a unit with a "hot" enclosure cows feel voltage gradients as they approach - and generally just stay away. Pigs are too curious, you just find them dead around the water tank, but hardly anyone has outdoor swine operations anymore either so that doesn't happen either.

You'll find dead cows laying around the water tank also if they've got their snout in the water when the unit goes south.
I have a few installs like this that are GFI protected and havent had any issues with them.
Better off paying the price for a GFCI as to have to pay for your customers dead livestock.

 

[kwired]

You'll find dead cows laying around the water tank also if they've got their snout in the water when the unit goes south.
I have a few installs like this that are GFI protected and havent had any issues with them.
Better off paying the price for a GFCI as to have to pay for your customers dead livestock.

I understand, from experience though there is is only one dead cow, the others just stay away.

It is the same way with electric fences, cows or even horses only get hit a time or two and after that they just stay away from it. You don't even have to energize it in many cases and it will contain them. With pigs, they have a higher curiosity level and have to come back and test that thing every so often.