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Stray voltage/currents can be reduced to acceptable levels. This handbook examines the history of stray voltage/current problems on farms; physical and electrical sources of these phenomena; physiological and behavioral bases for losses in milk production; methods for identifying, detecting, and mitigating stray voltage/current problems; and areas where further research may be warranted. (1991)

1. Introduction

Robert D. Appleman, Editor

Summary
History
Recognition
Early Field Experiences
Solutions
Where Do We Stand Now?

2. Sources of Stray Voltage/Current

David Ludington, Editor

Summary
Sources
Characteristics of a Source
Neutral/Ground System Voltage to Earth
Voltage Drop in Secondary Neutral
Neutral/Ground Bus and Equipment Grounds
Excessive Secondary Neutral Current
Caveat
Power Delivery Systems
Power Generation and Transmission
Primary Distribution
Single-Phase Service Drops
Three-Phase Service Drops
Additional Sources of Information

3. Physiological and Behavioral Effects

Daniel J. Aneshansley and R. C. Gorewit, Editor

Summary
Introduction
Physiological Basis for Sensitivity to Currents
Human Sensitivity
Electrical Currents That Affect Dairy Cows
Voltage Sensitivity
Controlled Research
Behavior and Physiology
Production, Reproduction, and Health
Observations from Dairy Farms
Symptoms Attributed to Stray Voltage
Farm Surveys
Problems with Interpreting Survey Data
Factors Affecting Response
Perception and Interpretation of Stimuli
Predictability and Controllability of Stimuli
Genetic Selection
Lactation
Learned Behavior
Animal-Operator Interaction
Conclusion

4. Mitigation

Robert Gustafson, Editor

Summary
Voltage Reduction
Active Voltage Suppression
Gradient Control
Retrofitting Existing Facilities
Isolation
Whole Farm Isolation
Single-Building-Service Isolation
Isolation of Grounded Equipment within a Single Service
Conclusion
Appendix: Examples
Example 1: Single-Phase Distribution Line
Example 2: Single-Phase Farmstead

5. Detection and Measurement

LaVerne Stetson, Editor

Summary
Detection
Point to Point
Point to Reference Ground
Interpreting Measurements
Instruments
Measurements
Voltage
Current
Resistance
Equipment Grounding
Investigation Procedures
Farm Secondary Systems
Primary Distribution Systems
Additional Sources of Information

6. Recommendations for Research

Lloyd B. Craine, Editor

Summary
Introduction
Physiological Effects
Power Systems
Load Growth
Power Quality
Transients
Power System Maintenance
General Recommendations on Power Systems
Direct Current Voltage and Current Systems
Measurement Problems
Electric and Magnetic Fields
Sensitivity of Animals
Where to Obtain Additional Information
Mitigation Equipment

7. Annotated Summary and Recommendations

Alan M. Lefcourt, Editor

Summary
Definition of Stray Voltage
An Elevated Neutral-to-Earth Voltage Is Not Stray Voltage Per Se
History
Sources
Animal Contact
Circuit Impedances
Neutral-to-Earth Voltages
Leakage or Coupled Sources
Physiological and Behavioral Effects
Sensitivity to Electric Currents
Electrical Currents That Affect Dairy Cows
Impedance of Cows
Normal Cow Behavior
Behavioral Responses to Current
Physiological Responses to Current
Factors Influencing Responses to Stray Voltages
Mastitis
Caveat
Conclusions
Mitigation
Voltage Reduction
Active Voltage Suppression
Gradient Control
Isolation
Detection and Measurement
Warning
Basic Measurement Procedures
Instrumentation
Investigation Procedures
Identification of Sources
Future Research
Physiology
Power Systems
Recommendations
Action Levels
New Construction
Existing Problems

8. Bibliography

David Kammel, Editor

9. Glossary

David Currence, Editor