Precision AVR: Unlocking Max Uptime for Top CNC Manufacturer


Computer numerical control (CNC) technologies are crucial in producing equipment, structure, and systems installed for daily usage. Industrial companies use CNC machines for drilling, boring, cutting, grinding, and other mechanical processes on different metal parts. Such procedures require reliability, precision, and control, particularly when manufacturing parts for mission-critical applications.


Hence, the responsibility falls on CNC manufacturers to ensure that the machines they supply perform consistently in the field. CNC machines must be capable of withstanding voltage irregularities commonly experienced in industrial environments. The underlying electrical and electronic components must function reliably to produce accurate process output, optimise energy usage and ensure a safe environment for the operators.


In this case study, we’ll explore the electrical challenges a leading CNC manufacturer face. We’ll also explore the solution the manufacturer took to ensure it continues to supply reliable and accurate CNC machines for its clients. 

Our Client 

Electro Scientific Industries (ESI) is a leading CNC machine supplier specialising in laser-based micro manufacturing solutions. With 75+ years of experience innovating manufacturing technologies, ESI now provides precision-guided CNC machines to the semiconductor industries. Major industrial suppliers use ESI’s machines to produce flex and rigid PCBs that electronic components sit on. 

PCB production requires immense precision, where pieces of conductive substrate go through several processes to imprint the electronics circuit. This involves via drilling, which requires micro or nanometer precision. A via is a drilled hole that connects electrical tracks on different layers of a PCB. In every production, the machine might drill tens of thousands of vias with strict expectations of meeting the required mechanical dimensions. 

ESI’s advancement in drilling technology is evident as it supplies top-quality PCB machining instruments capable of increasing yield and reducing costs. Its CNC equipment not only drills holes at high precision but also at pace and scale. ESI also incorporates software, test systems, and expert support for manufacturing critical parts for healthcare, automotive, aerospace, and other sectors.


Founded in 1944, the Oregon-based manufacturer continues to grow in strength over the decades. In 2019, MKS Instruments completed an acquisition of ESI for approximately $1 billion. Today, ESI is a reputable brand managed by MKS Instruments Equipment & Solutions Division.


The Challenges 


ESI’s laser-guided CNC machines are engineered with precision electronics, control circuits, motors, and other electrical parts. While the machine consists of state-of-the-art technologies, they require a stable and clean power supply to function reliably. Otherwise, those components will operate beyond their nominal voltage rating and risk prematurely degrading.


 As a CNC manufacturer, ESI has little control and oversight over how or where its machines are installed. Therefore, some machines might be exposed to voltage irregularities, which impact production workflow and result in equipment failure. To complicate the matter, most machines are subjected to voltage anomalies, a common issue in industrial facilities. 


Voltage irregularities and CNC machines 

We share several common voltage issues that affect CNC machines below.


Voltage Fluctuations

Voltage fluctuation is a phenomenon where the voltage amplitude sways beyond the tolerance at random intervals. Such incidents occur because of several causes: electrical issues from the distribution grid, power supply faults, and sudden varying loads. CNC machines might fail when exposed to prolonged voltage fluctuations, resulting in unplanned outages for industrial operators. 


Voltage Surges

Voltage surges are sudden spikes in the power supply line due to lightning strikes or other electrical disturbances from connected loads. On an unprotected line, surges traversed directly through the CNC machine’s internal components and might cause irreparable damages.


Voltage Sag

Voltage sag is a condition where the power supply line continuously drops below the nominal rating. In such situations, the CNC machine fails to receive the optimal voltage to perform efficiently. Some components, such as electrical motors, might compensate for the low voltage by consuming more current, and this results in overheating and eventual failure. 


Voltage Imbalance

Voltage imbalance affects CNC machines in different ways. It is characterised by varying voltage amplitude across the 3-phase supply line that powers the machine. Left unaddressed, voltage imbalance might cause severe electrical problems for operators, leading to costly repair or replacement. 

ESI seeks stable power for CNC machines


ESI understood that voltage stability and accuracy were vital to ensuring its clients experienced maximum benefit from their solutions. As a leading CNC machine provider, the company intends to prevent voltage irregularities from affecting the installed machines, regardless of the deployment environment. ESI wanted to ship reliable machines that could withstand harsh electrical conditions. 


ESI has no access to its client’s power distribution line or the local grid. There is little that the company can do beyond the scope of the machine itself, but that doesn’t discourage ESI. It was committed to designing a solution that allows the machine to receive a clean power supply independently from external infrastructure. With such intention, they collaborated with Ashley Edison. 


Ideal Recommendations  

Ashley Edison’s engineering team held in-depth discussions with ESI to seek sustainable solutions for their voltage challenges. It became apparent that the answer lies in incorporating a series of high precision automatic voltage stabilisers to ESI CNC machines. It was established that Automatic voltage stabilisers (or AVR for CNC machines)  would ensure high-value equipment are continuously protected from incoming surges, voltage fluctuation, transient and other harmful anomalies. 


How Automatic Voltage Stabilisers support CNC Machines

Automatic voltage stabilisers are protection devices that provides voltage optimisation for connected electrical loads. It consists of a feedback circuitry that automatically compensates for the voltage deviation from its nominal rating. This way, the load can continue to operate with the specified rating—regardless of power supply variation. 


In this case, the automatic voltage stabiliser mitigates voltage fluctuations and prevents voltage surges, sags and imbalances from affecting the CNC machines. The proposed solution allows ESI to deliver machines with the promised reliability, robustness and precision for different installation conditions and environments.


Boosting CNC Benefits

  • AVRs quickly offset voltage fluctuation so that CNC machines continuously receive clean and stable voltage.
  • Voltage stabilisers automatically disconnects the load from the incoming supply to prevent surges from damaging the equipment.
  • Voltage stabilisers boost sagging voltages and maintain consistent levels, allowing the CNC machine to operate continuously with predictable behaviour.
  • Voltage stabilisers balance voltages across each phase to prevent undesirable electrical issues. 


With the perfect outcome in sight, the Ashley Edison solutions team specifies the most ideal automatic voltage stabilisers that fit ESI’s broad range of machines. 


The Ashley Edison Solution 


Precision AVR

Ashley Edison’s series of AVRs are designed to deliver continuous stability and reliability for the Manufacturing and CNC Machining industry. These voltage stabilisers offer ultra-precise regulation of ±0.5%, a 10x improvement compared to most AVRs in the market. They are coupled with wide input variation tolerance of up to ±30%, plus total immunity to load change.


In Ashley Edison’s collaboration with ESI, more than 855 AVRs with capabilities up to 20 kVA, both single and 3 Phase units have been delivered.


These AVRs act as a stabilising force that allows CNC machines to function reliably and optimally. Instead of deriving power directly from the mains, the CNC machines receive a regulated power supply and protection from the AVRs. 


Ashley Edison offers the ideal power protection and maximum uptime for CNC machines. More importantly, the voltage stabilisers are built to prevent avoidable unplanned downtime and costly repair, or replacement. Thanks to the built-in high-quality Transient Voltage Surge Suppressor (TVSS) and other advanced protectionary features, Ashley Edison’s AVRs stop highly damaging spikes from affecting connected CNC machines.


Besides delivering precise voltage and power protection, Ashley Edison AVRs operate reliably with minimum maintenance. Premium-grade carbon brushes within the regulating modules ensure extra high MTBF and robustness that allows the AVRs to last beyond the average industrial lifespan. With a virtually maintenance-free and an energy-efficient design, these AVRs are considered smart investments to solve power issues for manufacturing CNC Machining and industries. Businesses relying on Ashley Edison’s protection solutions have also discovered substantial active and passive financial savings.




ESI witnessed immediate positive results after installing Ashley Edison AVRs. These protection systems negate voltage anomalies that would otherwise affect ESI’s customer’s operation. With the AVR in operation, ESI now consistently deliver CNC machines that meet stringent requirements in the industries they serve. 


Today, ESI continues to uphold their promise of innovating manufacturing beyond mechanical tools with Ashley Edison’s high-precision AVRs. The long-lasting collaboration between Ashley Edison and ESI demonstrates a sound decision in prioritising the improvement of voltage stability for themselves, and their customers.


About Ashley Edison

Ashley Edison is a leading Power Solution Provider with historically proven industry records. Since 1977, the Voltage Protection Specialist has continued to imbue innovation into a series of ever-evolving power protection designs for modern needs. With a team of solutions engineers and voltage specialists, we bridge the gap between technical prowess and business practicalities with precision-driven, robust and cost-friendly solutions.


For decades, our voltage stabilisers are field-tested in the most challenging environments—enabling us to deploy these voltage stabilising solutions in rural-based broadcasting facilities, government facilities, military use cases, high-sensitivity test labs and more. 


To learn how Ashley Edison solutions can improve your CNC Machining electrcial needs, contact us now.

Electro Scientific Industries (ESI)
2012 - Present
AVRs | Over 855 units of 20KVA units


From brownouts to severe voltage fluctuations, Ashley Edison takes care of all your power needs by delivering optimised, stable voltage supply to your electrical system.


Curious to learn more? Get in touch with us. We’ll get back to you with a quote or solution within 24 hours and put all your questions to rest.

ASHLEY Edison International LTD
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Three Phase

SESL-H-3P-S Model
Large Capacity Rating
200 to 2,000 KVA


Enclosure 335
1000W x 1300H x 580D (mm)
250~300 KVA ± 15%
120~200 KVA ± 20%


Enclosure 336
1280W x 1480H x 660D (mm)
400 KVA ± 15%
250 KVA ± 20%


Enclosure 337H
1880W x 1950H x 880D (mm)
500 KVA ± 15%
300 KVA ± 20%


Enclosure 339
1470W x 1950H x 1340D (mm)
600 ~ 1,500 KVA ± 15%
400 ~ 1,000 KVA ± 20%
300 ~ 750 KVA ± 25%
300 ~ 600 KVA ± 30%

Three Phase

SES-H-3P-S Model
Added I/P Breaker Protection
60 to 1,000 KVA


Enclosure 333
490W x 800H x 990D (mm)
≤ 100 KVA ± 15%


Enclosure 334
540W x 900H x 1000D (mm)
120 – 150 KVA ± 15%


Enclosure 335
1000W x 1300H x 580D (mm)
180 – 300 KVA ± 15%
120 – 200 KVA ± 20%
120 – 150 KVA ± 25%


Enclosure 336H
1880W x 1480H x 660D (mm)
400 KVA ± 15%
250 KVA ± 20%
180 ~ 200 KVA ± 25%


Enclosure 337H
1880W x 1950H x 880D (mm)
500 KVA ± 15%
300 KVA ± 20%
250 KVA ± 25%


Enclosure 339H
2170W x 1950H x 1340D (mm)
600~1,000 KVA ± 15%
400~600 KVA ± 20%
300~400 KVA ± 25%

Single Phase

SES-H-S Model
Added I/P Breaker Protection
1 to 100 KVA

Enclosure 102
270W x 460H x 490D (mm)
≤ 20 KVA ± 30%
≤ 15 KVA ± 20%
≤ 10 KVA ± 25%
≤ 10 KVA ± 15%

Enclosure 103
400W x 580H x 500D (mm)
25 KVA ± 15%
20 KVA ± 20%
15 KVA ± 25%

Enclosure 332
380W x 670H x 780D (mm)
30 KVA ± 15%

Enclosure 333
490W x 800H x 990D (mm)
40 ~ 50 KVA ± 15%
25 ~ 30 KVA ± 20%
20 ~ 25 KVA ± 25%
15 ~ 20 KVA ± 30%

Enclosure 334
540W x 900H x 1000D (mm)
60 ~ 75 KVA ± 15%
40 ~60 KVA ± 20%
30 ~ 50 KVA ± 25%
25 ~ 40 KVA ± 30%