Date post: | 21-May-2015 |
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Education |
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Ground Current – A Joint Committee of the OFA, CFFO and Farm & Food Care
Brent Royce & Lorne LantzUncontrolled Electricity (Agriculture) Working
Group
Steering Committee Objectives The goal is:• To raise awareness of this issue with farmers. • Improve awareness and communication with hydro
utilities.• Have a website to provide information and record
farmers’ experiences with uncontrolled electricity. • Sector-leading research into mitigation strategies for
individuals and the province.
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History of Farm Stray Voltage in Ontario
(from Barry Fraser)
Stray, tingle or neutral to earth voltage has been implicated as a problem for dairy and other livestock herds for many years.
60’s/70’s• First identified in North America
80’s• First factsheet by OMAFRA - 1982• Filters/blockers increasingly used on dairy farms in 80’s/90’s
What is Stray Voltage/Current?
• Low-level voltage often exists between electrically grounded farm equipment such as metal stabling, feeders, or milk pipelines and the earth.
• Current is the flow of electrons through these conductive objects to earth.
Origins of Stray Voltage/Current
• A primary neutral current (off-farm)• Secondary neutral current resulting from use of 120
volt equipment on farm (unbalanced loads). • Fault’s or shorting equipment• Variable speed motors• In an OMAF study, nearly all of the voltage found could
be attributed to primary neutral resistance in the distribution system. Only a few isolated cases were identified where on-farm faults or wiring problems made a major contribution
Multi-Grounded Primary Neutral SystemTransformer Service
Panel
Earth
5 Amps X 2 Ω = 10 V
2 Amps X 2 Ω = 4 V
3 Amps
4 V
4 V 4 V
Grounding System
Substation(End of 3 phase)
If an animal touches a grounded metal object where these low voltages are found, a small electric current will pass through the animal. The voltage that causes this small current is known as “animal contact voltage,” “stray voltage,” “tingle voltage,” or “ground current.”
Testing and Evaluation
Current Testing
Pete Stern – Maple Ridge
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Reported Impacts on Livestock PerformanceDairy, swine, beef, poultry, sheep, horses
Based on a talk by Barry Fraser
• Decreased feed and water intake
• Reduced milk production• Uneven and incomplete
milk out• Reluctance to enter milking
parlour/barn • Nervousness and aggressive
behavior• Less rate of gain
• Increased somatic cell count• Lameness in legs and feet• Reproduction impacts
– false heats, increased abortion rates – birth defects, drop in conception– altered sex ratios
Some Research has been done in the past on Animal Health
• Vet Res Commun. 1990;14(4):299-308.• Small electric currents affecting farm animals and man: a review
with special reference to stray voltage. II. Physiological effects and the concept of stress.
• Hultgren J.• Author information • Department of Animal Hygiene, Faculty of Veterinary Medicine,
Swedish University of Agricultural Sciences, Skara.• Abstract• The literature on the influence of small, steady electric currents on
animal health, especially cardiovascular and endocrinological functions and milk let-down, and the effects on milk production is reviewed, with special reference to the problem of stray voltage.
Hydro One’s Involvement
Where Farmers Can Go for Information
In the Search box type: Uncontrolled Electricity
Where Farmers Can Go for Information