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Stray voltage is the occurrence of
electrical potential The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is defined as the amount of work energy needed to move a unit of electric charge from a reference point to the specific point in ...
between two objects that ideally should not have any voltage difference between them. Small voltages often exist between two grounded objects in separate locations, due to normal
current Currents, Current or The Current may refer to: Science and technology * Current (fluid), the flow of a liquid or a gas ** Air current, a flow of air ** Ocean current, a current in the ocean *** Rip current, a kind of water current ** Current (stre ...
flow in the power system. Large voltages can appear on the enclosures of electrical equipment due to a fault in the electrical power system, such as a failure of insulation.


Terminology

Stray voltage is any case of undesirable elevated electrical potential, but more precise terminology gives an indication of the source of the voltage. Neutral to earth voltage (NEV) specifically refers to a difference in potential between a locally grounded object and the grounded return conductor, or
neutral Neutral or neutrality may refer to: Mathematics and natural science Biology * Neutral organisms, in ecology, those that obey the unified neutral theory of biodiversity Chemistry and physics * Neutralization (chemistry), a chemical reaction in ...
, of an electrical system. The neutral is theoretically at 0 V potential, as any grounded object, but current flows on the neutral back to the source, somewhat elevating the neutral voltage. NEV is the product of current flowing on the neutral and the finite, non-zero impedance of the neutral conductor between a given point and its source, often a distant substation. NEV differs from accidentally energized objects because it is an unavoidable result of normal system operation, not an accident or a fault in materials or design.


Definitions


Official definition (draft)

In 2005, the
Institute of Electrical and Electronics Engineers The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...
(IEEE) convened Working Group 1695 in an attempt to lay down definitions and guidelines for mitigating the various phenomena referred to as stray voltage. The working group attempted to distinguish between the terms ''stray voltage'' and ''contact voltage'' as follows: *Stray voltage is defined as "A voltage resulting from the normal delivery and/or use of electricity (usually smaller than 10 volts) that may be present between two conductive surfaces that can be simultaneously contacted by members of the general public and/or their animals. Stray voltage is caused by primary and/or secondary return current, and power system induced currents, as these currents flow through the impedance of the intended return pathway, its parallel conductive pathways, and conductive loops in close proximity to the power system. Stray voltage is not related to power system faults, and is generally not considered hazardous." *Contact voltage is defined as "A voltage resulting from abnormal power system conditions that may be present between two conductive surfaces that can be simultaneously contacted by members of the general public and/or their animals. Contact voltage is caused by power system fault current as it flows through the impedance of available fault current pathways. Contact voltage is not related to normal system operation and can exist at levels that may be hazardous."


Working definition

In spite of the above definitions, the term ''stray voltage'' continues to be used by both utility workers and the general public for ''all'' occurrences of unwanted excess electricity. For example, at the annual "Jodie S. Lane Stray Voltage Detection, Mitigation & Prevention Conference", held at the Con Edison headquarters in New York City in April 2009, which attracted the presidents of most major utilities from throughout the United States and Canada, the utility leaders continued to use ''stray voltage'' for all occurrences of unwanted excess electricity. The term ''contact voltage'' was used only once, possibly because "contact voltage" is generally the fault of the supply, network or installation company. Few companies are willing to openly discuss faults of theirs, let alone ones as life-threatening. It would seem that ''stray voltage'' is now the common term for all unwanted voltage leakage as it categorises the fault as part of normal operation, therein limiting liability. In New York City, a woman named Jodie S. Lane was electrocuted by a five-foot by eight-foot road utility vault plate energized by an "improperly insulated wire" in January 2004. In the coverage of her death and the growing concern regarding the role of public utilities in electrical safety in the urban environment, both the media and the New York State regulatory agency used ''stray voltage'' for neutral-to-earth voltage (NEV), but conceded that the notoriety of the Lane incident had caused ''stray voltage'' to be a term that is well recognized by the public. At that point, the regulator used ''stray voltage'' to refer to any "voltage conditions on electric facilities that should not ordinarily exist. These conditions may be due to one or more factors, including, but not limited to, damaged cables, deteriorated, frayed or missing insulation, improper maintenance, or improper installation." In the same document, the commission accepted NEV to be a naturally occurring condition. Since that time, the term “stray voltage” has had at least two very different definitions. This situation is cause for confusion among utilities, regulators, and the public. The term "stray voltage" is commonly used for all unwanted electrical leakage, by both the general public and many electrical utility professionals. Other more esoteric phenomenon that also result in elevated voltages on normally non-energized surfaces, are also referred to as “stray voltage.” Examples are voltage due to
capacitive coupling Capacitive coupling is the transfer of energy within an electrical network or between distant networks by means of displacement current between circuit(s) nodes, induced by the electric field. This coupling can have an intentional or acciden ...
, current induced by power lines, EMF,
lightning Lightning is a naturally occurring electrostatic discharge during which two electrically charged regions, both in the atmosphere or with one on the ground, temporarily neutralize themselves, causing the instantaneous release of an average ...
, earth potential rise, and problems stemming from open (disconnected) neutrals.


Causes


Coupled voltages

Ungrounded metal objects close to
electric field An electric field (sometimes E-field) is the physical field that surrounds electrically charged particles and exerts force on all other charged particles in the field, either attracting or repelling them. It also refers to the physical field ...
sources such as neon signs or conductors carrying
alternating current Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...
s can have measurable voltage levels caused by
capacitive coupling Capacitive coupling is the transfer of energy within an electrical network or between distant networks by means of displacement current between circuit(s) nodes, induced by the electric field. This coupling can have an intentional or acciden ...
. Since voltages detected by high-impedance instruments disappear or become greatly reduced when a low impedance is substituted, the effect is sometimes called phantom voltage (or ghost voltage). The term is often used by electricians, and might be seen, for example, when measuring the voltage at a lighting fixture after removing the bulb. It is not unusual to measure phantom voltages of 50–90 volts when testing the wiring of ordinary 120 V circuits with a high-impedance instrument. While the voltage produced may read almost to the full supply voltage, the
capacitance Capacitance is the capability of a material object or device to store electric charge. It is measured by the change in charge in response to a difference in electric potential, expressed as the ratio of those quantities. Commonly recognized are ...
or mutual inductance between the wires of
building wiring Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure. Wiring is subject to safety standards for design and installation. Allowable ...
systems is typically quite low and incapable of supplying significant amounts of
current Currents, Current or The Current may refer to: Science and technology * Current (fluid), the flow of a liquid or a gas ** Air current, a flow of air ** Ocean current, a current in the ocean *** Rip current, a kind of water current ** Current (stre ...
. However, in
overhead transmission Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is d ...
work on or near high-voltage lines, safety rules require connecting a conductor to
earth ground In electrical engineering, ground or earth is a reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be connec ...
during maintenance, since induced voltages and currents on a conductor may be sufficient to cause electrocution or serious injury.


Capacitive leakage through insulation

Alternating current is different from direct current in that the current can flow through what would ordinarily seem to be a physical barrier. In a
series circuit Two-terminal components and electrical networks can be connected in series or parallel. The resulting electrical network will have two terminals, and itself can participate in a series or parallel topology. Whether a two-terminal "object" is a ...
, a
capacitor A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals. The effect of ...
blocks direct current but passes alternating current. In power transmission systems, one side of the circuit, known as the
neutral Neutral or neutrality may refer to: Mathematics and natural science Biology * Neutral organisms, in ecology, those that obey the unified neutral theory of biodiversity Chemistry and physics * Neutralization (chemistry), a chemical reaction in ...
, is grounded to dissipate
static electricity Static electricity is an imbalance of electric charges within or on the surface of a material or between materials. The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is na ...
and to reduce hazardous voltages caused by insulation failure and other electrical faults. It is possible to get a shock by only touching the ''hot'' wire, due to the person's body being capacitively coupled to the ground upon which the person stands, even if the person is standing on an insulated surface.


Induced voltages

Classical
electromagnetic induction Electromagnetic or magnetic induction is the production of an electromotive force (emf) across an electrical conductor in a changing magnetic field. Michael Faraday is generally credited with the discovery of induction in 1831, and James Cle ...
can occur when long conductors form an open grounded loop under and parallel to transmission or distribution lines. In these cases, current is induced in the loop when a person makes contact with it and ground. Since this involves real current flow, it is potentially hazardous. This type of induced current occurs most often on long fences and distribution lines built under high-power transmission lines.


Degraded insulation on power conductors

Stray voltage may be caused by damaged or degraded insulation. Failing insulation is essentially a high impedance fault which will allow current to flow through any available path to ground, a condition which can cause shocks or fires if left unmitigated. This leakage can occur when there is damage caused by physical, thermal, or chemical stresses to insulation on power lines, especially but not limited to underground or underwater cables. Examples of this damage are swollen or cracked insulation from overheating, abrasions caused by digging or ground seizing, and corrosion damage from salt or oil exposure. Electrical leakage can also occur due to moisture, salt, dust, and dirt buildup on open air insulators in overhead power distribution. If the leakage in these cases is severe enough, it can lead to a pole fire.


Leakage from single-wire earth return

The term "stray voltage" is used for the gradient (rate of change with respect to distance) of
electrical potential The electric potential (also called the ''electric field potential'', potential drop, the electrostatic potential) is defined as the amount of work energy needed to move a unit of electric charge from a reference point to the specific point in ...
in the surface of the soil, associated with single-wire earth return
electricity distribution Electric power distribution is the final stage in the delivery of electric power; it carries electricity from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmissi ...
systems used in some rural locations. This gradient is low at points far away from the earth return connections, but increases near the ground rods where the metallic circuit enters the earth.


Neutral return currents through the ground

In
three phase Three-phase electric power (abbreviated 3φ) is a common type of alternating current used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires (or four including an optional neutral ...
four-wire ("wye") electrical power systems, when the load on the phases is not exactly equal, there is some current in the neutral conductor. Because both the primary and secondary of the distribution transformer are grounded, and the primary ground is grounded at more than one point, the earth forms a parallel return path for the neutral current, allowing part of the neutral current to continuously flow through the earth. This arrangement is partially responsible for stray voltage. Stray voltage is a result of the design of a 4 wire distribution system and as such has existed as long as such systems have been used. Stray voltage became a problem for the dairy industry some time after electric milking machines were introduced, and large numbers of animals were simultaneously in contact with metal objects grounded to the electric distribution system and the earth. Numerous studies document the causes, physiological effects, and prevention, of stray voltage in the farm environment. Today, stray voltage on farms is regulated by state governments and controlled by the design of equipotential planes in areas where livestock eat, drink or give milk. Commercially available neutral isolators also prevent elevated potentials on the utility system neutral from raising the voltage of farm neutral or ground wires.


Railway stray current

Typically a rail transit systems will have at least one of the rails used as a return conductor for the traction current. This arrangement is common, based on economic considerations, since it does not require the installation of an additional return conductor. This rail is in contact with the earth at many places throughout its length. Since current will follow every parallel path between source and load, some part of the traction current will also flow through the earth. This is normally referred to as leakage current or stray current. The amount of leaking current depends on the conductance of the return tracks compared to the soil; and on the quality of the insulation between the tracks and soil. Where the railway uses
direct current Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or ev ...
, this stray current can cause damage to other buried metallic objects by
electrolysis In chemistry and manufacturing, electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from n ...
and accelerate corrosion of metal objects in contact with the soil.


Effects


Electrolysis and corrosion

Dissimilar buried metals such as copper and steel can function as the poles of a
galvanic cell A galvanic cell or voltaic cell, named after the scientists Luigi Galvani and Alessandro Volta, respectively, is an electrochemical cell in which an electric current is generated from spontaneous Oxidation-Reduction reactions. A common apparatus ...
, using moist soil as the electrolyte. Stray direct currents in soil may counteract the anti-corrosion effect of a
cathodic protection Cathodic protection (CP; ) is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects the metal to be protected to a more easily corroded "sacrifi ...
system. Design of
high voltage direct current A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curre ...
transmission systems must take care so that current flowing in the earth does not cause objectionable corrosion to buried objects such as pipelines. The stray currents from railways create or accelerate the electrolytic corrosion of metallic structures located in the proximity of the transit system. This causes metal pipes, cables and earthing grids laid in the ground near the tracks have a much shorter life which is high importance in regard to safety and economy.


Persons

Small stray voltages may never be noticed and may only be detected with a
voltmeter A voltmeter is an instrument used for measuring electric potential difference between two points in an electric circuit. It is connected in parallel. It usually has a high resistance so that it takes negligible current from the circuit. ...
. Larger voltages may have a range of effects, from barely perceptible to dangerous
electric shock Electrical injury is a physiological reaction caused by electric current passing through the body. The injury depends on the density of the current, tissue resistance and duration of contact. Very small currents may be imperceptible or produce a ...
s, or unintended electrical heating resulting in fires. Normally, metal electrical equipment cases are bonded to ground to prevent a shock hazard if energized conductors accidentally contact the case. Where this bonding is not provided or has failed, a severe hazard of electric shock or
electrocution Electrocution is death or severe injury caused by electric shock from electric current passing through the body. The word is derived from "electro" and "execution", but it is also used for accidental death. The term "electrocution" was coin ...
is presented when circuit conductors contact the case. In any situation where energized equipment is in intimate electrical contact with a person or animal (such as swimming pools, surgery, electric milking machines, car washes, laundries, and many others), particular attention must be paid to elimination of stray voltages. Dry intact skin has a higher resistance than wet skin or a wound, so voltages that would otherwise be unnoticed become significant for a wet or surgical situation. Potential differences between pool water and railings, or shower facilities and grounded drain pipes are not uncommon as a result of neutral to earth voltages (NEV), and can be a major nuisance, but are usually not life-threatening. However, contact voltage resulting from damaged insulation on a current carrying conductor can be very dangerous, and can lead to shock or electrocution. Such a condition can arise spontaneously from mechanical, thermal, or chemical stress on insulation materials, or from unintentional damage from digging activity, freeze-frost seizing, corrosion and collapse of conduit, or even workmanship issues. Contact voltage energizes objects which are normally safe – fences, telephone booths, street signs, etc. Anywhere buried electric wiring exists, a failure can occur in that wiring and create conditions that allow electricity to flow into the immediate surroundings. Some systems have protective devices such as circuit breakers or Ground Fault Circuit Interrupters (GFCI), designed to isolate such a fault. However, in the absence of protective devices, if the devices fail, or if they are not installed correctly, a fault will go undetected until it either causes a failure of the circuit or until it is found by a person.


Farm animals

Stray voltage can have harmful effects on animal health and productivity. Some
dairy A dairy is a business enterprise established for the harvesting or processing (or both) of animal milk – mostly from cows or buffaloes, but also from goats, sheep, horses, or camels – for human consumption. A dairy is typically located on ...
farmers have claimed damage to yields or stock caused by it. Dr. Douglas J. Reinemann, Professor of Biological Systems Engineering at
University of Wisconsin–Madison A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United Stat ...
, reported on stray voltages on dairy farms in 2003. Investigation of stray voltage claims must also consider other animal health concerns.


Legal proceedings in Wisconsin

In 2003, the
Wisconsin Supreme Court The Wisconsin Supreme Court is the highest appellate court in Wisconsin. The Supreme Court has jurisdiction over original actions, appeals from lower courts, and regulation or administration of the practice of law in Wisconsin. Location The Wi ...
upheld a
judgement Judgement (or US spelling judgment) is also known as ''adjudication'', which means the evaluation of evidence to make a decision. Judgement is also the ability to make considered decisions. The term has at least five distinct uses. Aristotle s ...
of $1.2 million against the Wisconsin electrical utility WEPCO in ''Hoffman'' v. ''Wisconsin Electric Power Company''. The Hoffman family, dairy farmers near
New London New London may refer to: Places United States *New London, Alabama *New London, Connecticut *New London, Indiana *New London, Iowa *New London, Maryland *New London, Minnesota *New London, Missouri *New London, New Hampshire, a New England town ** ...
, had sued WEPCO after several years of declining production. WEPCO had measured on the farm currents due to stray voltage below one milliampere, the "level of concern" set by the
Public Service Commission of Wisconsin The Public Service Commission of Wisconsin is an independent regulatory agency responsible for regulating public utilities in the energy, telecommunications, gas and water companies located in U.S. state of Wisconsin. As of 2021, the agency regul ...
, but the court ruled on procedural grounds that the utility could be found negligent under
common law In law, common law (also known as judicial precedent, judge-made law, or case law) is the body of law created by judges and similar quasi-judicial tribunals by virtue of being stated in written opinions."The common law is not a brooding omniprese ...
even though they met the state standard. The Hoffmans had presented, the court said, a viable alternative theory that stray voltage had caused them economic harm. In 2017 a jury sided with farmers Paul and Lyn Halderson for a $4.5 million settlement against Xcel Energy. The Haldersons claimed stray voltage from power lines hurt their 1,000 cow herd and lowered milk production. The jury found that Xcel subsidiary – Northern States Power – was "negligent with respect to the delivery of electrical service." The jury awarded $4.09 million for economic damages and another $409,000 for "inconvenience, annoyance and loss of use and enjoyment" of property.


Public concerns about stray voltage

In metropolitan areas, stray voltage issues have become a major concern. Many of these areas have large amounts of aging underground and aboveground electrical distribution equipment in crowded public spaces. Even a low rate of insulation failures or current leakage can result in hazardous exposure to the general public.
Consolidated Edison Consolidated Edison, Inc., commonly known as Con Edison (stylized as conEdison) or ConEd, is one of the largest investor-owned energy companies in the United States, with approximately $12 billion in annual revenues as of 2017, and over $62 ...
in
New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...
has had frequent incidents of stray voltage, including the electrocution death of Jodie S. Lane in 2004, while walking her dog in
Manhattan Manhattan (), known regionally as the City, is the most densely populated and geographically smallest of the five boroughs of New York City. The borough is also coextensive with New York County, one of the original counties of the U.S. state ...
. In 2009, the Jodie S. Lane Public Safety Foundation announced a publicly accessible website with maps showing thousands of reported stray voltage locations in New York City. In addition, the Foundation sponsors the "Jodie S. Lane Stray Voltage Detection, Mitigation & Prevention Conference", an annual meeting attended by power utilities and regulators from around the country to discuss stray voltage detection programs. The Foundation also initiated and advocates regular mobile scanning by utility companies for stray voltage hazards. In Boston, NSTAR Electric (formerly Boston Edison) has also had problems with hazardous stray voltages, which have killed several dogs during the 1990s. As a result, the
City of Boston Boston (), officially the City of Boston, is the state capital and most populous city of the Commonwealth of Massachusetts, as well as the cultural and financial center of the New England region of the United States. It is the 24th- most p ...
government started a program to detect, report on, and repair stray voltage hazards.
Toronto Hydro Toronto Hydro Corporation is an electric utility that operates the electricity distribution system for the city of Toronto, Ontario, Canada. As of 2018, it serves approximately 772,000 customers and delivers approximately 19% of the electricity ...
pulled all employees off regular duty on the weekend of January 30, 2009 to deal with ongoing stray voltage problems in the city. This came after as many as five children were shocked though none suffered serious injury. The stray voltage problem had claimed the lives of two dogs in the previous few months. In March 2013, Californian Simona Wilson won a $4 million lawsuit against her power company after stray voltage from a substation near her house repeatedly shocked her and members of her family whenever they were in the shower.Woman Shocked in Shower by Stray Voltage Wins $4 Million Lawsuit
Yahoo News Yahoo! News is a news website that originated as an internet-based news aggregator by Yahoo!. The site was created by a Yahoo! software engineer named Brad Clawsie in August 1996. Articles originally came from news services such as the Associate ...
, 21 Mar 2013. Retrieved 22 Mar 2013.
The United States Social Security Administration, Administrative Law Judge, Edward Bergtholdt, in an August 17, 2000 decision awarded Michael Gunner permanent disability from exposure to stray voltage.


Stray/contact voltage detection

Stray voltage is generally discovered during routine electrical work, or as a result of a customer complaint or shock incident. A growing number of utilities in urban areas now conduct routine periodic and systematic active tests for stray voltage (or more specifically, contact voltage) for public safety reasons. Some incipient electrical faults may also be discovered during routine work or inspection programs which are not specifically focused on stray voltage. Equipment used to detect stray voltage varies, but common devices are electrical tester pens or electric field detectors, with follow-up testing using a low-impedance voltmeter. Electrical tester pens are hand-held devices which detect a potential difference between the user's hand and the object being tested. They generally indicate on contact with an energized object, if the potential difference is above the sensitivity threshold of the device. Reliability of the test can be affected if the user is at an elevated potential him/herself, or if the user is not making firm contact with a bare hand on the reference terminal of the tester.
Capacitive coupling Capacitive coupling is the transfer of energy within an electrical network or between distant networks by means of displacement current between circuit(s) nodes, induced by the electric field. This coupling can have an intentional or acciden ...
is the mechanism used by electrical tester pen devices. Because the capacitance between an object and a current source is typically small, only very small currents can flow from the energized source to the coupled object. High-impedance digital or analog voltmeters may measure elevated voltages from non-energized objects due to this coupling, in effect providing a misleading reading. For this reason, high-impedance voltage measurements of normally non-energized objects must be verified. Verification of a voltage reading is performed using a ''low-impedance'' voltmeter, which usually has a
shunt resistor In electronics, a shunt is a device that creates a low- resistance path for electric current, to allow it to pass around another point in the circuit.Rudolf F. Graf, ''Modern dictionary of Electronics'', Mc-Graw Hill, 1968 Library of Congress 68-1 ...
load bridging the voltmeter terminals. Since very little current can flow from a coupled surface through the small shunt or meter resistance, capacitively coupled voltages will collapse to zero, indicating a harmless "false alarm". By contrast, if an object being tested is in contact with a
current source A current source is an electronic circuit that delivers or absorbs an electric current which is independent of the voltage across it. A current source is the dual of a voltage source. The term ''current sink'' is sometimes used for sources fed ...
, or coupled by a very large capacitance (possible but unlikely in this context), the voltage will drop only slightly as dictated by
Ohm's Law Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equa ...
. In this latter case, real power is being delivered, indicating a potentially hazardous situation. Electric field detectors detect the electric field strength relative to the user's body or mounting platform. By sensing
electric field An electric field (sometimes E-field) is the physical field that surrounds electrically charged particles and exerts force on all other charged particles in the field, either attracting or repelling them. It also refers to the physical field ...
gradients at a distance, they can detect energized objects without making direct contact, making these instruments useful for scanning or screening large areas for potential electrical hazards. A low electric field reading also provides a definitive indication that no objects are energized within a tested area. Electric field detectors respond to all field sources, and any positive indications must be verified with a low-impedance voltmeter to eliminate false positives. Electric field proximity sensing also has other industrial applications from manufacturing to building security. Since stray voltage cannot be seen, smelled, or heard, there is no easy way for the public to know when a dangerous condition exists. Periodic testing is an important precaution, but it is possible that a dangerous condition can develop without warning.


See also

* Disturbance voltage * Earth potential rise *
Earthing system An earthing system (UK and IEC) or grounding system (US) connects specific parts of an electric power system with the ground, typically the Earth's conductive surface, for safety and functional purposes. The choice of earthing system can affect ...
*
Electrical bonding Electrical bonding is the practice of intentionally electrically connecting all exposed metal items not designed to carry electricity in a room or building as protection from electric shock. If a failure of electrical insulation occurs, all bonded ...
*
Gas leak A gas leak refers to a leak of natural gas or another gaseous product from a pipeline or other containment into any area where the gas should not be present. Gas leaks can be hazardous to health as well as the environment. Even a small leak in ...
* Neutral and ground * Shaft voltage


References


External links


University of Wisconsin–Madison Report on Stray Voltage

'Electrified Cover Safeguard' website

'Stray voltage' website
from the '' LaCrosse Tribune'', including their award-winning coverage
Self-Help Guide: Stray Voltage Detection
Wisconsin Farm Electric Council (2/1997), well written, for farmer-consumers, at

Stray Voltage portal
Wisconsin Public Service Stray Voltage site


(technical)
Pacific Gas and Electric Power Quality Bulletin No. 2, "Stray Voltage"
(10/2004)
First conference about "Stray currents in our environment" - November 29, 2007, Ester Technopole Limoges, France

Stray voltage description and mitigation
{{DEFAULTSORT:Stray Voltage Electrical parameters