Case study: How Fluke oscilloscopes help Zero Tolerance reduce stray voltage by re-engineering dairy farm grounding systems

After years of work in dairy barns, electrician John Hoefert kept seeing the same frustrating pattern: farms would invest heavily in genetics, feed, housing, and automation—yet performance and animal comfort still hit an invisible ceiling. In many cases, the culprit wasn’t nutrition or equipment quality. It was the electrical environment.

He founded Zero Tolerance to help farms reduce stray voltage and electrical noise by addressing the root cause: the design and condition of their grounding and power systems. To do that work consistently—and to prove the results—Zero Tolerance relies on Fluke oscilloscopes to capture real-world waveforms in harsh barn conditions and reveal what simple “average-only” measurements can miss.

Note: Farmers use “stray voltage” to describe the effect animals feel. Technically, it shows up as neutral-to-earth voltage (NEV) along with harmonics and electrical harmonics/noise that can spread through a facility when grounding and bonding systems aren’t engineered for modern loads.

Zero Tolerance uses Fluke oscilloscopes to capture real-world waveforms, pinpoint the source of electrical noise, and verify that a corrective grounding redesign keeps stray voltage low. After remediation and verification, farms often report improvements such as:

• Client-reported milk gains commonly range from +5 to +8 lb/cow/day, with some farms reporting higher gains (up to +14 lb/cow/day), depending on conditions and concurrent changes.
• Improved reproduction rates.
• Fewer stress-related issues and better overall herd stability (client-reported).

They also use oscilloscopes to evaluate equipment (VFDs, lighting drivers, pumps) so replacements don’t reintroduce electrical noise that can undo a clean grounding system. Products that meet Zero Tolerance’s electrically-clean benchmarks are labeled ‘Zero Tolerance Certified’ to help farms maintain a low-noise electrical environment over time.

Their work has gained attention from Dairy Farmers of America (DFA), a farmer-owned global dairy cooperative with more than 9,500 farmer-owners. Zero Tolerance Certified products are available from DFA’s supply company, DFA Farm Supplies, expanding farmer access to verified ‘electrically clean’ options.

Background

When John Hoefert, founder and chief analyst at Zero Tolerance, completed his electrical apprenticeship, he was tasked with a huge project: troubleshooting wiring at a dairy farm that was experiencing problems with its RFID system. These systems help dairy farmers track how much milk individual cows produce, providing an important pathway for farmers to monitor the health of their herd.

While RFID issues are a common problem, there was no straightforward resolution. “They were never really resolving the problem,” explained Hoefert. “Instead of chasing symptoms, Hoefert corrected underlying grounding and bonding problems—after that, the RFID failures stopped.”

Around the same time, the farmer also observed improvements in herd behavior and productivity. And once the RFID problem was corrected, “The cows got healthier. We couldn’t understand why,” said Hoefert. That outcome pushed him to investigate what else was changing in the electrical environment.

When animals avoid water, feed, or stall areas due to discomfort, intake and performance drop—often without an obvious ‘smoking gun.’ Naturally, the farmer was thrilled to receive the benefits of healthier cows along with a perfectly functioning RFID system. That outcome pushed him to investigate the root cause behind the herd’s improvement.

After years of field work across many farms, Hoefert traced a recurring root contributor: stray voltage driven by grounding and power-system design problems. When grounding and bonding are not engineered for modern loads, unwanted voltage and electrical noise can appear throughout a facility—creating discomfort, avoidance behaviors, and chronic stress. Ultimately, this leads to stressed cows who don’t eat or drink as much as they should.

Challenges

Stray-voltage guidance varies widely by state and across the industry, which makes it difficult for farms and electricians to work toward a consistent, verifiable endpoint. Zero Tolerance addresses that gap by working to achieve an “electrically clean” facility standard—keeping neutral-to-earth voltage (NEV) below 70 mV under normal operating conditions, even as equipment changes. In Hoefert’s experience, many barns operate at levels well above that threshold. And it’s not only cows that suffer when too much stray voltage is present. “It’s all animal agriculture, period,” said Hoefert. “It’s chickens, pigs, turkeys, fish farms, you name it. They’re all impacted.”

Zero Tolerance uses Fluke oscilloscopes on-site to capture waveforms and identify what’s injecting electrical noise, then uses those insights to guide a facility-wide grounding redesign. Because modern barns include switching loads (VFDs, LED drivers, pumps), stray voltage can pulse and spike—an oscilloscope reveals what simple averaging tools can miss. The oscilloscope captures the waveforms in real time so they can identify dominant frequency patterns and correlate them to likely contributors (drives, lighting, wiring paths, grounding/bonding issues). They standardized on Fluke after years of field experience because measurement repeatability matters at very low signal levels.

“Measuring very low-level stray voltage reliably is tough,” said Jim Neawedde, director of operations at Zero Tolerance. “We standardized on Fluke because it’s repeatable in the field—and it lets us see the waveform, not just a number.” The challenge was sustainment: months after bringing stray voltage down, it could creep back when equipment was replaced or new loads were added. Often, a single equipment change could reintroduce electrical noise and degrade the electrical environment.

“Patterns emerged—some products were electrically ‘clean,’ others consistently injected noise,” explained Hoefert. “I had to start going onto farms and telling them they couldn’t use certain products without risking the return of stray voltage.”

Implementation

Zero Tolerance’s core work is re-engineering the farm’s grounding and bonding architecture. To help those results hold, they created a testing and approval process so replacement equipment doesn’t reintroduce electrical noise. The same approach applies to new construction—design the electrical topology correctly from day one.

Using oscilloscopes and a defined test process, Zero Tolerance evaluates equipment to determine whether it will preserve—or degrade—an electrically clean barn. Approved products help farms keep stray voltage low in the long term, even as components are upgraded. Current certified categories include lighting, VFDs, ventilation systems, and fans.

Zero Tolerance shares objective waveform findings and performance benchmarks with manufacturers so designs can be improved. For products that don’t pass the test, Zero Tolerance can work with manufacturers to make the necessary design improvements to improve animal health. “These groups are happy to get rid of stray voltage, but they don’t even know it’s an issue,” explained Hoefert. “They say, ‘Okay, we’re doing something wrong, great. Tell us what to do so we can meet your requirements.’”

Next, Zero Tolerance plans a certification for electricians focused on methods, verification, and sustainment—so barns stay electrically clean after upgrades and repairs. “As electricians, all we’re taught is to make things safe for people,” said Hoefert. “We’re not really taught about animal welfare.” The new certification will teach electricians how to identify and correct stray voltage issues, giving farmers peace of mind that their barns are both safe and productive.

“Certified electricians can go to a farm and say, ‘We’re Zero Tolerance Certified, and when we’re done, the electrical environment will meet defined benchmarks—and you’ll have verification to prove it,’” said Hoefert.

Results

Across recent projects, Zero Tolerance reports client-observed milk gains commonly in the +5 to +8 lb/cow/day range after remediation and verification. “The average milk gain we’ve gotten over the past two years is an additional five to eight pounds of milk per cow, per day,” said Hoefert. Some farms report higher gains, up to +14 lb/cow/day, though results vary by site conditions and management changes.

The word is spreading, with farms across the U.S., Mexico, and Canada seeking Zero Tolerance’s expertise. But it’s not just individual farmers taking notice.

DFA has also recognized the far-reaching impact of Zero Tolerance’s work.

Through DFA’s CoLAB Accelerator, Zero Tolerance showcased its approach to industry leaders and expanded partnerships tied to farm performance and animal welfare. Following the program, DFA invited Hoefert to speak to subsequent CoLAB cohorts. Zero Tolerance Certified products will soon be featured on the DFA Farm Supplies website.

“They’ve really taken us to a new level, not just in their support and business connections but even more than that,” said Hoefert. “They care about their farms so much that they’re pushing us to be more than we are right now because the farms need it.”

The partnership reflects a growing focus on electrical system design as a lever for animal comfort, equipment reliability, and farm ROI. It signals a growing awareness that stray voltage is a serious animal welfare and productivity issue that affects farms worldwide. By partnering with organizations like DFA, Zero Tolerance is helping to shift the standard for electrical safety in agriculture and bring animal health to the forefront of modern farm management.

Zero Tolerance uses Fluke oscilloscopes to establish repeatable benchmarks and verify that improvements hold under real operating conditions. “Our standard lives or dies on verification,” said Neawedde. “Fluke gives us repeatable, high-fidelity data in harsh barn environments—so our grounding redesign is based on evidence, not opinion, and we can prove the system is electrically clean and stays that way.”