LIVESTOCK EQUIPOTENTIAL PLANES

[AZJeff2013]

I am in the process of designing a veterinary building that includes separate bovine and equine buildings. The equine building has gravel stalls with concrete corridors leading to the stalls. The bovine building has concrete floors throughout.

I have studied NEC 547 and the American Society of Agricultural and Biological Engineers standard EP473 regarding equipotential planes and cannot get a warm fuzzy feeling about veterinary use buildings needing a equipotential plane due to the temporary, transient use. We will, of course, bond all metallic equipment that the animals can come into contact with but the actual concrete slab equipotential plane and voltage gradient ramps seem excessive for this building/use type.

Thoughts are extremely appreciated!!!

Jeffrey
Marion, IL

 

[Dennis Alwon]

Mike holt has a great video on stray voltage and agriculture equipotential plane. If you don't want to watch it all begin watching at 45 minutes

 

[gadfly56]

I am in the process of designing a veterinary building that includes separate bovine and equine buildings. The equine building has gravel stalls with concrete corridors leading to the stalls. The bovine building has concrete floors throughout.

I have studied NEC 547 and the American Society of Agricultural and Biological Engineers standard EP473 regarding equipotential planes and cannot get a warm fuzzy feeling about veterinary use buildings needing a equipotential plane due to the temporary, transient use. We will, of course, bond all metallic equipment that the animals can come into contact with but the actual concrete slab equipotential plane and voltage gradient ramps seem excessive for this building/use type.

Thoughts are extremely appreciated!!!

Jeffrey
Marion, IL

Well, unless you can guarantee that any faults will be temporary and transient, I think the standards don't care if the animal will be there 10 hours or 10 weeks. Suppose it was your prize stud bull going in for care, how would you feel about your animal not being protected according to code, just because "it's only a little while"?

 

[Cow]

We've done miles of equipotential plane work in large dairy barns. It's not complicated once you start doing it. Repetitive more than anything, really.

Just make sure they use wire mesh or rebar in a grid before pouring the concrete. We use DB/grounding rated split bolts, IK-6's if I remember right for most all of our work. Used crimps for a while, found out we like split bolts more. The barns we do are 2200' long typically, so a roll of mesh doesn't make it the whole distance. We typically split bolt the end of one mesh to the next and throw a couple split bolts down the side to the adjacent mesh. This is above and beyond what the NEC requires though.

We bond anything isolated and metallic that is set in the slabs, metal fencing, gate posts, headlocks/stanchions, etc.

We typically use:
#8 bare solid CU
DB ufer clamps
IK-6's
#4 DB lay in lugs

Some combination of the above will carry us all the way through an equipotential plane project.

Just an FYI, when our regular inspector isn't available, the replacement or substitute inspectors don't even know what they're looking at when we show them the equipotential plane. The majority of electricians don't ever come in contact with art. 547 and as such, either do most inspectors.

Get ready to explain what you're doing so the inspector understands.

 

[tom baker]

2200 feet thats a lot of dairy.

 

[romex jockey]

Just an FYI, when our regular inspector isn't available, the replacement or substitute inspectors don't even know what they're looking at when we show them the equipotential plane. The majority of electricians don't ever come in contact with art. 547 and as such, either do most inspectors.

Get ready to explain what you're doing so the inspector understands.

My entire 'farm' career Cow

thx

~RJ~

 

[Mystic Pools]

We've done miles of equipotential plane work in large dairy barns. It's not complicated once you start doing it. Repetitive more than anything, really.

Just make sure they use wire mesh or rebar in a grid before pouring the concrete. We use DB/grounding rated split bolts, IK-6's if I remember right for most all of our work. Used crimps for a while, found out we like split bolts more. The barns we do are 2200' long typically, so a roll of mesh doesn't make it the whole distance. We typically split bolt the end of one mesh to the next and throw a couple split bolts down the side to the adjacent mesh. This is above and beyond what the NEC requires though.

We bond anything isolated and metallic that is set in the slabs, metal fencing, gate posts, headlocks/stanchions, etc.

We typically use:
#8 bare solid CU
DB ufer clamps
IK-6's
#4 DB lay in lugs


Some combination of the above will carry us all the way through an equipotential plane project.

Just an FYI, when our regular inspector isn't available, the replacement or substitute inspectors don't even know what they're looking at when we show them the equipotential plane. The majority of electricians don't ever come in contact with art. 547 and as such, either do most inspectors.

Get ready to explain what you're doing so the inspector understands.

This method of bonding really is not much, if at all, different then when we pour a concrete slab in prep for a natural stone finish or a finished poured concrete patio around a pool. We'll use #4 (1/2") rebar or wire mesh-depends on project application and size.

 

[Cow]

This method of bonding really is not much, if at all, different then when we pour a concrete slab in prep for a natural stone finish or a finished poured concrete patio around a pool. We'll use #4 (1/2") rebar or wire mesh-depends on project application and size.

I've never done a pool, but I'll bet what you're saying is true. It can't be far off from what a pool takes.

 

[ptonsparky]

Don’t ignore the gradient ramps on both the entrance AND exits. You will have a pretty good visual of why. :ashamed:

 

[kwired]

This method of bonding really is not much, if at all, different then when we pour a concrete slab in prep for a natural stone finish or a finished poured concrete patio around a pool. We'll use #4 (1/2") rebar or wire mesh-depends on project application and size.

Except you don't ordinarily have gradient ramps at pools. But look at how much more surface area a large animal like a cow can span across (that much more potential voltage when there is a gradient present) compared to humans when just casually standing or walking.

Don’t ignore the gradient ramps on both the entrance AND exits. You will have a pretty good visual of why. :ashamed: