ground current presentation -

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