6 Questions You Must Ask
Before Selecting A Stray
Voltage Expert
1. Do they have a proven, step-by-step process that ensures your time and money
will be well invested?
The cold hard truth about stray voltage is that it may NOT be the source of your problem. Odd
livestock behaviors, decrease in milk production, reproduction issues… those are all symptoms
typical to a stray voltage problem, but in reality, they can have many causes that may be
intertwined with one another. The pie chart below shows this:
To make sure your time and money are well invested, it’s important not to jump to conclusion and
do just as doctors do: perform a diagnostic before prescribing a solution.
Agrivolt achieves this using a proven 4 step process.
Proven Stray Voltage 4 Step Process
Step 1: assessment call (a pre diagnostic to better understand your situation and judge if an
analysis would be required)
Step 2: on site analysis (a thorough, on site diagnostic of your situation, to confirm whether or
not stray voltage is in cause)
Step 3: solution implementation
Step 4: monthly monitoring (unique to Agrivolt, see question 5 for more details)
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2. Will their analysis be based on science?
It only seems like common sense, but be certain to ask the person seeking to be your stray voltage
authority, “how do you identify if we have stray voltage concerns?” Make sure their answer makes sense,
is based on proven principles, and can be verified by unaffiliated sources.
As an example, to analyze the quantity of current likely to pass through the body of an animal, Agrivolt
uses the following scientific data, as compiled through industry studies over the past 30 years:
Perception Threshold to electricity for a pig, chicken or cow = 1 mA
Sensitivity Threshold to electricity for a pig, chicken or cow = 3 mA
Body resistance of a pig to electricity we use = 400 ohms
Body resistance of a chicken to electricity we use = 1000 ohms
Body resistance of a cow to electricity we use = 250 ohms
To determine a safety threshold at 60 Hz, we use Ohm’s law:
Safety threshold = Body resistance X Sensitivity Threshold
Livestock Safety Threshold
Pig Safety Threshold = 1.2V (400 ohms X 3 mA)
Chicken Safety Threshold = 3 V (1000 ohms X 3mA)
Cow Safety Threshold = 0.750V (250 ohms X 3mA)
What this means for you is that, if the current does not reach the levels identified for each species
of animals, it is likely that stray voltage is not a major cause of production loss in your herd.
At lower levels, the animals may sense the current, but only with an awareness, not with negative
consequences. This is what we call the “perception threshold”, which should never be confused
with the “sensitivity threshold” (also called “safety threshold”).
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3. Are their solutions accepted within the National Electric Code?
Many solutions can provide some potential relief from stray voltage concerns, but are they safe? Some
actually put you and your herd at much greater risk than just stray voltage. It is only appropriate,
and legal, to follow the National Electric Code in all efforts to minimize your stray voltage concerns.
Article 250 of the NEC is the area that deals with grounding and bonding. Specifically, “250.6
Objectionable Current Flowing through the Grounding Path” is the section of this code that allows for:
“(B) Stopping Objectionable Current. If multiple neutral-to-ground connections results in an
objectionable flow of current, one or more of the following shall be permitted to be made,
provided that the fault current path is permanent, electrically continuous, capable of safely
carrying the maximum fault likely to be imposed on it, and it has sufficiently low impedance to
facilitate the operation of overcurrent devices under fault conditions [250.2(A)(5)].
1. Discontinue the improper neutral-to-ground connections.
2. Change the locations of the neutral-to-ground connections.
3. Interrupt the continuity of the conductor or conductive path interconnecting the grounding
connections.
4. Take other suitable remedial action satisfactory to the authority having jurisdiction.”
This is the NEC approved method Agrivolt uses in seeking stray voltage remedies.
4. Can the results of their solutions be measured?
If it can’t be measured, how will you know if it is corrected? Even if animal behavior improves, perhaps
something else changed? Just as your physician would want to check your blood pressure, and not
just accept your sense that “I am feeling OK,” a stray voltage expert would want to document the
before and after treatment levels of current.
To document the “before”, Agrivolt perform an exhaustive analysis to quantify the current levels on
your farm, and documents through a detailed written report.
Even with an assessment call (step one in of Agrivolt process), sometimes this report identifies that the
levels found are below those of concern for the safety level of the animals.
However, about 75% of the time, it is found that there are levels of current flowing that may cause
discomfort and production losses in the herd.
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Here is an example of what the data may look like in such problematic situations:
Current
Minimum
maximum
214 mA
936 mA
1056 mA
total
Secure
level
acceptable
1992 mA
187 mA
No
7968 mV
750 mV
No
4.0 ohms
Impedance
Voltage
Startup
856 mV
3744 mV
4224 mV
You will note that the “Secure level” is identified at 750 mV for a dairy cow.
On this specific farm, the impedance (or resistance of the farm grounding network) was measured at 4
ohms.
By using the scientific formula of Ohm’s Law, we are able to determine the “Secure level” of current to
be 187 mA (750 mV / 4 ohms = 187 mA).
Therefore any reading over 187 mA will likely expose the cows to potential negative effects.
In this example, even during the “minimum” measurement (lowest 15 min consecutive time period), the
levels exceed our threshold. This is best represented in the below graph:
Agrivolt guarantees through their solutions to remedy these measurements to within the secure level
defined.
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5. Will you be able to track these results over an extended period of time?
What good is a temporary solution? As described earlier, perhaps something else changed in the
dynamic cycle that is today’s farming. Whatever solution is attempted, it must be done with an eye
on tomorrow’s challenges. “We fixed it” is not enough. “We remedied the current situation and will
continue to monitor into the future” is a much more complete solution.
Agrivolt has been committed to monitoring since day one. Their patented Potential Equalizer solution
has an LCD readout giving real time measurements of current flowing on the neutral to ground path.
This means that you will be able to tell immediately if there is a fault on the system, as an audible
alarm sounds and a warning light flashes identifying the panel in which the problem is sensed.
Additionally, Agrivolt offers a revolutionary SmartScan system that can provide offsite 24/7 monitoring
with detailed reporting and predictive problem solutions for temperature, arcing, phase imbalance,
voltage sags or overages, current usage and much more. It is by far the most innovative technology
available today.
6. Can they provide a list of satisfied customers?
Any service provider can make a host of claims. The proof is if the existing customers tell the same story,
and continue to tell that story months or years later. If the provider is very careful about whom he or
she recommends you speak with, you may want to search further.
At Agrivolt, we are very proud to say we have been involved with over 2000 livestock operations
across North America, and are happy to provide lists of available contacts. In fact, just check our
website for those that have taken the time to help us produce these videos:
http://Agrivolt.com/testimonials
What to do next
Wondering if stray voltage might impact your livestock safety and performance?
Agrivolt has developed a “30 Minute Stray Voltage Assessment” which we conduct over the
telephone with you, for free.
Call us now at:
1-866-574-1753
© 2014 all rights reserved NUVOLT CORPORATION INC.
SmartScan® is a registered trademark of Nuvolt Corporation Inc.
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