Stray Voltage
Information Resources
- What is Stray Voltage?
MREC offers Stray Voltage Investigators’ Courses, typically held annually in Wisconsin. Visit the Events page for more. - News and Research
- Organizations
- Publications from MREC and other sources
- MREC Conference Presentations
What is Stray Voltage?
The term stray voltage has been used for the past 40 years to describe a special case of voltage developed on the grounded neutral system of a farm. If this voltage reaches sufficient levels, animals coming into contact with grounded devices may receive a mild electrical shock that can cause a behavioral response. At voltage levels that are just perceptible to the animal, behaviors indicative of perception such as flinches may result with little change in normal routines. At higher levels avoidance behaviors may result.
The term stray voltage is often applied incorrectly to other electrical phenomena such as electric fields, magnetic fields and most recently electric current flowing in the earth. These phenomena are generally referred to as EMF or Electric and Magnetic Fields. The physiological interactions with these phenomena are different than the mild shock associated with stray voltage. For more information on EMF and other electrical exposures, go to the EMF Page.
The following is a broad range of information resources intended to increase your understanding of stray voltage. Should you have information to contribute to this Web page, please contact the MREC at mrec@cals.wisc.edu.
Stray Voltage Videos
This section presents seven videos on stray voltage, what it is, how it originates, and the parts for conducting a stray voltage investigation.
Introduction: What is stray voltage and where does it come from? – Stray voltage describes a low-level voltage present on the grounded neutral network of all farm electrical systems. This video introduces what stray voltage is, how and where it is generated, and the importance of stray voltage investigations.
Animal responses to stray voltage exposure – What are the voltage thresholds under which animals become aware of the current, start feeling discomfort, and change behaviors? This video responds to these questions.
Components of a stray voltage investigation – There are three main components of a stray voltage investigation: Measurement of the animal contact voltage levels, measurement of utility neutral voltage, and measurement of the farm grounded neutral system. This video describes the details of these three main components.
The cow contact measurement – The animal (or cow) contact measurement is the most important part of the stray voltage investigation because it tells us what the animals are actually exposed to. This video expands on the principles of this measurement.
Exposure locations: Watering devices, feeding locations, milking, and building transitions – The most common place for animals to come into contact with voltage is at watering devices as water systems are usually connected to the farm’s grounded neutral system. This video presents the different locations where stray voltage is more likely to be present.
Other electrical phenomena – Stray voltage is not the only electrical exposure at the farm. In this video, learn what are these electrical exposures and the differences with stray voltage.
What should I do about stray voltage? Investigation, regulations, and mitigation – If you think you might have a stray voltage problem on your farm, always start with voltage measurements at animal contact locations. Information on how you, or your electrician, can conduct cow contact measurements is available at the Midwest Rural Energy Council Website www.mrec.org.
News And Research
- Virtual Fencing Research. A Selection of Five Publications on the Impacts of Virtual Fencing on Animals: March 5, 2021
- Stray voltage affects cow behavior, milk production. Progressive Dairyman: January 6, 2015.
- Stray voltage not the root of all problems. Hoard’s Dairyman Intel: March 3, 2014.
- Stray voltage in dairy systems. Recording of Penn State Extension Technology Tuesday webinar presented by Doug Reinemann, University of WI-Madison, Sept. 23, 2014. Resources from this presentation include slide sets Stray Voltage, The Research Perspective, Stray Voltage Field Guide, and What do we Know about Stray Voltage?
- Stray voltage and milk quality: a review. Veterinary Clinics of North America Food Animal Practice. 2012 Jul;28(2):321-45.
Organizations
- Michigan Agricultural Electric Council
- Minnesota Public Utilities Commission
- Public Service Commission of Wisconsin
- Stray Voltage Documents
- Uniform Interconnect Rules for the State of Wisconsin
Publications from MREC and other sources
- Minnesota Stray Voltage Guide, Sept. 2015. Outlines the steps farmers, electrical contractors, utilities and their advisors can take to discover and resolve stray voltage concerns on livestock farms.
- Iowa Stray Voltage Guide, July 2014. A Guide Addressing Stray Voltage Concerns. This guide supplements the USDA Handbook 696 “Red Book” “Effects of Electrical Current/Voltage on Farm Animals:How to Detect and Remedy Problems.(see below)
- Wind Turbines and Farm Stray Voltage (2014)
- What Do We Know About Stray Voltage? (2010)
- Stray Voltage Field Guide (2009)
- Equipotential Planes for Stray Voltage Reduction: Installation Guidelines
- Planning Electrical Systems for Dairy Expansions
- Stray Voltage Detection: A Self-Help Guide
- Answers to Your Stray Voltage Questions: Backed by Research (2011) Wisconsin Public Service
- Installation and Operation of Fencers, Cow Trainers and Crowd Gates
- Managing Dairy Cattle for Cow Comfort and Maximum Intake, by J. Keown and P. Kononoff, University of Nebraska-Lincoln Extension. Not specifically about stray voltage but a general guide to cow comfort.
MREC Conference Presentations
- Cows’ Immune Response and Stray Voltage, Lorraine Sordillo, Michigan State University (2017)
- Fact Sheets from the National Mastitis Council
1. A Practical Look at Environmental Mastitis
2. A Practical Look at Contagious Mastitis
3. Recommended Milking Procedures
4. Dry Cow Therapy
5. Post-milking Teat Disinfection
6. The Value and Use of Dairy Herd Improvement Somatic Cell Count
- Fact Sheets from the National Mastitis Council
- New Minnesota Stray Voltage Guide, Tim Weir, Weir Engineering Services (2016)
- South Dakota Stray Voltage Law, Ed Anderson, South Dakota Rural Electric Association (2016)
- IEEE Guide to Understanding, Diagnosing and Mitigating Stray and Contact Voltage, Chuck DeNardo, We Energies (2016)
- Assessing Animal Exposure Risk from Stray Voltage Test Results, Doug Reinemann, University of Wisconsin-Madison (2016)
- DC Measurements in Stray Voltage Investigation, Mike Stringfellow, PowerCET Corporation (2016)
- Stray Voltage In the News, Chuck DeNardo, We Energies (2016)
- Advanced Topics in Stray Voltage Investigation–Tom Seidl, We Energies, and Paul Ortmann, Idaho Power (2015)
- Stray Voltage Testing- Counterpoise Calculations, Tom Seidl, We Energies (2015)
- Stray Voltage Testing- Distinguishing Contributions from Different Sources, Tom Seidl, We Energies (2015)
- Stray Voltage Testing- Transformers, Winding Configurations, Load Box, Tom Seidl, We Energies (2015)
- Iowa Stray Voltage Guidelines, Tony Harvey (2015)
- Stray Voltage and Mastitis: A Review– Doug Reinemann, University of Wisconsin-Madison (2014)
- Stray Voltage and Livestock Health– John Roberts, DVM, WI Dept. of Ag, Trade and Consumer Protection (2014)
- Stray Voltage Legislation Review – Paul Ortmann, Idaho Power (2014)
- Stray Voltage Testing on Large Dairies, Mark Cook, MCC (2013)
- Working With Oscilliscopes- (an MREC Pre-Conference Workshop given in 2012)
- Preconference Seminar Handouts, Tom Seidl, WE Energies (2012)
- Fluke 105B Scopemeter, Tom Seidl, WE Energies (2012)
- Tekscope Play-by-Play Manual, Bob Fick, Alliant Energy (WI) (2012)
- Oscilloscope Basics, Todd Montevideo, Wisconsin Public Service (2012)
- Oscilloscope Applications, Paul Ortmann, Idaho Power Company (2012)
- Oscilloscope Applications – Handout Paul Ortmann, Idaho Power Company (2012)
- Oscilloscope Applications – Hands-on Paul Ortmann, Idaho Power Company (2012)
- Oscilloscope Applications – Exercises Paul Ortmann, Idaho Power Company (2012)
- Human Contact Voltage Detection Protocols, David Kalokitis, Power Survey Company (2012)
- Capturing Fencer Transients with a Fluke 199C Oscilloscope, Tom Seidl, WE Energies (2012)
Older archived presentations concerning legal matters and stray voltage, or instrumentation and stray voltage
- Update on Michigan Stray Voltage Cases and Qualification of Experts under Dubert Standard, Julie Lam, Warner Norcross & Judd. (2009)
- Anatomy of a Stray Voltage Trial, Rodrick Lewis, DVM, JD, Warner Norcross & Judd, LLP. (2007)
- Updates on Recent Legal Developments in Stray Voltage, Keith Tinsey (2003)
- Stray Voltage Complaint to the MI Public Service Commission, James M. Schrandt, Agricultural Services Director (2001)
- Michigan Update (2003) on Legal Developments in Stray Voltage Keith Tinsey, Michigan State University (2003)
- Instrument Basics and Common Measurement Errors C. Forster, Phasorlabs, (2003)
- Waveform Lab C. Forster, Phasorlabs, (2003)