Dr. Stringfellow's
Stray Voltage Page


Stray Voltage Links:

Cornell NRAES

Wisconsin Public Service Commission

University of Wisconsin

Wisconsin Agricultural Survey Statistics

University of Minnesota

Midwest Rural Energy Council

Michigan Agricultural Electrical Council

Ontario Ministry of Agriculture

University of Alberta

USDA Bulletin on Utility Distribution Neutral Sizing


Dr. Stringfellow Business Home


Welcome to Dr. Stringfellow's Stray Voltage page. 

Stray Voltage is defined as a small voltage (typically below 10 volts) occurring between two points that can be contacted by a person or animal.  Such small voltages are normally not hazardous but if perceived can result in potentially adverse behavioral responses. Persons are most likely to encounter stray voltage in a wet location, especially swimming pools and spas.  The greatest concern, however, has been the exposure of animals, especially dairy cattle.  The behavioral response in animals has been identified by some workers as leading to economic losses.

Stray voltage in dairy farms was first identified in New Zealand in 1962 and in the USA in 1969.  Early concerns were small power-frequency voltages (50 Hz or 60 Hz) resulting from the grounding of the electrical system powering the facility.  These can occur from both on-farm and off-farm sources.  On-farm sources are the grounding conductors of the mains power and the farm electrical loads.  Off-farm sources are usually the distribution lines of the serving electric utility, especially where grounding practices can transfer voltages from the multiply-grounded neutrals of a wye-distribution system directly onto the farm electrical system.  Small power-frequency voltages are often referred to as "conventional" stray voltage.

More recently, stray voltage problems have also been ascribed to short-duration electrical signals (transients) and to earth currents associated with electricity distribution.  Some concern has also been made of electrical and magnetic fields and direct voltages.  These are often referred to as "unconventional" stray voltage.

My stray voltage professional interests and consulting practice include the following:

Measurement of conventional stray voltage and dairy farm power quality

Measurement of the source and origin of transients on dairy farms 

Misapplication of buried grounded conductors ("rings of life")

Electromagnetic fields and induction

Measurement of the source and origin of AC and DC earth currents

Use and misuse of recording instruments on dairy farms

If you are interested in my help in solving a stray-voltage related problem, please contact PowerCET Corporation, where you will find full details of consulting and training services that we offer, including our fee schedule.

If you'd like to reach me directly, my contact information can be found on the PowerCET home page.

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