equapotential plane

[Lee Bredlau]

I'm going to doing a large dairy barn this next spring, it is a free stall barn with robotic milkers, 450 cows in this barn. My question is if the concrete contractor is NOT going to use
re bar or wire mesh in the floor do I have to create a grid with copper wire?

 

[Dennis Alwon]

I think 547.10 has the answer

547.10 Equipotential Planes and Bonding of Equipotential
Planes. The installation and bonding of equipotential
planes shall comply with 547.10(A) and (B). For the purposes
of this section, the term livestock shall not include
poultry.


(A) Where Required. Equipotential planes shall be installed
where required in (A)(1) and (A)(2).


(1) Indoors. Equipotential planes shall be installed in confinement
areas with concrete floors where metallic equipment
is located that may become energized and is accessible
to livestock.


(2) Outdoors. Equipotential planes shall be installed in
concrete slabs where metallic equipment is located that
may become energized and is accessible to livestock.
The equipotential plane shall encompass the area where
the livestock stands while accessing metallic equipment
that may become energized.


(B) Bonding. Equipotential planes shall be connected to
the electrical grounding system. The bonding conductor
shall be solid copper, insulated, covered or bare, and not
smaller than 8 AWG. The means of bonding to wire mesh
or conductive elements shall be by pressure connectors or
clamps of brass, copper, copper alloy, or an equally substantial
approved means. Slatted floors that are supported
by structures that are a part of an equipotential plane shall
not require bonding.

 

[Cow]

The dairies we do over here, the concrete contractor installs either a wire mesh or a rebar grid for the equipotential plane depending on the location. This is something that needs to be installed by the concrete contractor. It is not economical to pay electricians to install a grid before the pour when they could have the 10/hr concrete laborers do it the same time they are setting the forms up. A fact I would make known to the customer who will ultimately end up paying the higher price. The dairies we work on over here have multiple barns in the 850-2200' range, so installing mesh is no small project.

 

[ptonsparky]

The guy doing the concrete needs to get with it or he needs to go. This is not a small "oops" that can be corrected later and mesh/rebar in the floor is the method to use.

i would think Wisconsin would have this covered.