livestock waterers - safe installation in cold climates ... livestock waterers - safe installation...
TRANSCRIPT
1
Livestock Waterers - Safe
Installation in Cold Climates and
the Use of Electrically Heated
Waterers
Robert Fick Ph.D., PE
Senior Agricultural Engineer
Alliant Energy
2
Why this discussion?
• Livestock waterers need a heat source in
northern climates
• Livestock waterers often are electrically
heated
• Livestock waterers may be a location
where stray voltage can be a concern
3
What questions do I hope to discuss?
• How does voltage get to a waterer?
• What is required or recommended for
livestock waterers (drinkers)?
• What types of waterers are available?
• What suggestions and recommendations
are there for installation?
• How and when do you test at waterers?
Assume that we are talking about waterers with
equipment grounding that are not faulting
4
Three locations of a livestock
waterer
1. In a building with electrical source
2. Near a building with electrical source
3. Remote from a building with electrical
source
7
What questions do I hope to discuss?
• How does voltage get to a waterer?
• What is required or recommended for
livestock waterers (drinkers)?
• What types of waterers are available?
• What suggestions and recommendations
are there for installation?
• How and when do you test at waterers?
14
What questions do I hope to discuss?
• How does voltage get to a waterer?
• What is required or recommended for
livestock waterers (drinkers)?
• What types of waterers are available?
• What suggestions and recommendations
are there for installation?
• How and when do you test at waterers?
15
Three types of waterers
• Energy free
• Electrically heated without conductive
contacts (often plastic)
• Electrically heated (mounted or drop in
heater)
17
Area of 4ft section of uninsulated pipe per diameter
Height of
uninsulated
pipe (in)
Pipe
diameter
(in)
Area (in2) of
bottom
Area (in2) of
4ft high pipe
below
insulation
Total area
(ft2)
3.14*r2
3.14*d*H columns (3+4)/144
48 6 28 904 6.5
48 8 50 1206 8.7
48 10 79 1507 11.0
48 12 113 1809 13.3
48 14 154 2110 15.7
48 16 201 2412 18.1
48 24 452 3617 28.3
20
Examples of overnight ice
thickness in a beef dry lot situation• Energy free water fountains were found to function adequately
provided they are properly design , properly installed and utilized an
appropriate riser pipe. (Schott 1993 Manitoba)
• Cobett
-
38
What questions do I hope to discuss?
• How does voltage get to a waterer?
• What is required or recommended for
livestock waterers (drinkers)?
• What types of waterers are available?
• What suggestions and recommendations
are there for installation?
• How and when do you test at waterers?
39
Suggestions and
Recommendations for Installation
• For freestalls and indoor locations
– Where is electrical heat needed?
– Leave options with electrical
– Segment water lines in building, replaceable
lines, and separate lines (where possible not
under concrete), may want water line on
outside of building
– Equipotential planes
41
Suggestions and
Recommendations for Installation
• For remote waterers consider:
– Equipotential planes
– Waterers without conductive surfaces
• Be aware of measurements due to electric fields
– Additional grounding of waterer
– Separately derived systems
45
V ~ 0
With this type of heater, there is no conductive
connection between the water and the
equipment ground
46
When and How do you test at
waterers? (Case by Case)• Address customer concerns
• Is it wired safely and correctly?– If only two wires (no equipment ground), not safe
– No ground or plane (manufacturer’s specifications and NEC may be time applicable)
• Need to know conditions if you are to suggest grounding, equipotential plane, different waterer or other options
• Best Defense is to have programs and information available to take care of voltages of concern