Stray Voltage Testing

An independent company working directly for the farmer. Stray Voltage Testing, LLC has been in business for twenty two years and has conducted on-farm testing for over 2300 dairy farms throughout   New York   New England   Pennsylvania   Ohio   Indiana   Maryland   and   Michigan.


Stray Voltage Testing, LLC
105 Sedgewick Park
New Hartford, NY. 13413
(315)  735-0952


Serving the Dairy Industry since 1985...

What is Stray Voltage?

Facts: Stray voltage is a function of normal AC 60 cycle per second electrical current that exists within any electrical distribution system. As current travels through a system, it must always return to its source. In doing so it develops voltage in the system's neutral wires and across other grounding paths that are parallel to earth.

Increased use of electrical equipment on dairy farms means more current moves through the distribution system, thus increasing stray voltage. Current may travel through the metal that cows come into contact with, making milking stanchions, water troughs, and feed bunks ideal grounding paths.

Sources of stray voltage may be either on-farm or off-farm.  Stray Voltage Testing's Electronic Grounding System (EGS) reduces stray voltage from both sources.

Types: Stray voltage may be constant or intermittent. Constant stray voltage is easy to measure and can be detected with the most commonly available meters. However, actual surveys done on dairy farms have shown that as motors start (whether on or off-farm) voltage peeks occur. These happen very quickly and are of significant intensity.

Stray Voltage Protection: Various approaches have been utilized in attempt to remove or reduce the level of stray voltage on dairy farms. Each of these approaches have drawbacks which the farmer should consider.

Rewiring: Rewiring assumes that a faulty condition exists. In many situations this is true. However, in many actual cases the farmer went through the expense of rewiring only to find that the stray voltage was still present on the farm. While every attempt should be made to install wiring per National Electrical Code compliance with this standard does not guarantee protection from stray voltage.

Isolation: Isolation is designed to inhibit the passage of stray voltage from the utility's primary neutral to the farm's secondary neutral.  By severing the farm's neutral system from the utility, isolation may reduce stray voltage on the farm.  However, actual farm measurements show that isolation does not protect the farm from stray voltage spikes caused by motors starting on the farm.  In addition, voltage coming from current in the ground generated by neighboring farms is not corrected.

Equipotential Planes: Equipotential planes can reduce problems from stray voltage.  However, planes must be constructed in all areas where electrically grounded equipment is present in areas exposed to cow contact.  Construction of the planes is disruptive to daily milking activities and costly on existing farms.  In addition, farmers with planes have cited problems in moving cows onto the protected areas due to the potential voltage difference between the protected  and non protected area.
*None of these approaches alert you to a malfunction.  Accordingly, damage to your herd from excessive voltage may occur before corrective action is indicated.