Press Releases
New AGL-MAR Series Ground Fault Relay for Marina Power Safety
San Jose, CA — NK Technologies is proud to announce the launch of the AGL-MAR Ground Fault Relay, a purpose-built ground fault detection relay designed specifically for marina and shore-power applications.
The AGL-MAR Series expands NK Technologies’ industry-leading ground fault protection portfolio, offering one of the largest aperture diameters in its class while maintaining a compact DIN-rail mountable footprint — ideal for modern electrical panels in marine environments.
Key Features & Benefits:
- Marina-Specific Ground Fault Protection — Designed to meet the unique demands of marina shore power systems, the AGL-MAR includes two jumper-selectable trip points for both 30 mA shore power and 100 mA branch circuit applications, providing flexible protection tailored to common marina electrical standards.
- Comprehensive Fault Monitoring — Monitors all current-carrying conductors in single- and three-phase systems to detect earth leakage and help prevent shock hazards and equipment damage.
- Reliable Output & Control — Features a dependable SPDT (Form C) relay with auto-reset, enabling seamless operation with breakers equipped with a 120 VAC shunt trip accessory.
- Robust, User-Friendly Design — With integral DIN rail mounting, finger-safe terminals, and a “push-to-test” button with LED status indication, the AGL-MAR is engineered for ease of installation, testing, and maintenance.
- Zero-Sum Operating Principle — Uses NK Technologies’ proven zero-sum magnetic balancing detection to sense even slight imbalances caused by leakage current — ensuring fast, reliable fault detection.
- Fast Response Time — Typical response times in the range of 50–150 ms deliver swift system protection when ground leakage is detected.
- Designed & Assembled in the USA, reinforcing NK Technologies’ commitment to quality and reliability.
About NK Technologies
NK Technologies has over 50 years of experience in delivering high-performance current sensing products for industrial and commercial applications. The company’s solutions are trusted for their accuracy, reliability, and innovation across global markets.
How to Choose the Right Voltage Transducer: A Practical Selection Guide
NK Technologies’ “How to Choose a Voltage Transducer” guide helps engineers and system designers select the right voltage transducer for their specific application by walking through the key criteria that influence product choice.
It explains how input voltage characteristics (such as range, AC vs. DC, and whether bidirectional measurement is required) affect selection, and it clarifies the importance of True RMS measurement for accurate readings in noisy environments.
The guide also covers how to choose appropriate output signal types (e.g., 0–5 VDC, 0–10 VDC, 4–20 mA), power supply options (including loop-powered or external power), and mounting preferences (DIN rail vs. panel). Additionally, it highlights that all NK Technologies voltage transducers carry UL/cUL and CE certifications for safety and performance.
For deeper technical background, download our whitepaper, “What is a Voltage Transducer?” and watch the accompanying video (need link) to see key selection tips in action —both available on the NK Technologies engineering resources page.
VT3-OS Series AC Voltage Transducer Monitors Voltage up to 600 VAC for Three-Phase Applications
San Jose, CA — NK Technologies proudly announces the introduction of the VT3-OS Series AC Voltage Transducer, engineered to deliver accurate, reliable voltage monitoring for three-phase applications across industrial and commercial systems.
Designed and assembled in the USA, the VT3-OS Series expands NK Technologies’ voltage sensing portfolio with a robust transducer that delivers True RMS voltage measurement, flexible mounting options, and integral fault detection features suitable for challenging electrical environments.
Key Features & Benefits:
- Precise Three-Phase Voltage Monitoring – The VT3-OS Series accurately senses three-phase voltages in common ranges (120, 240, and 480 VAC) up to 600 VAC, enabling dependable measurement in industrial systems and automation environments.
- Phase Loss Detection – Built-in phase loss detection with an SPST Form A relay output provides enhanced system protection by alerting operators to voltage drop or loss conditions that could impact equipment performance.
- Versatile Configuration Options – Available in both 3-wire (Line-Line) and 4-wire (Line-Neutral) configurations, the VT3-OS supports common power distribution architectures while delivering industry-standard analog outputs proportional to the measured voltage.
- Flexible Mounting & Powering – With both DIN rail and panel mount housings, the VT3-OS fits easily into control panels and electrical cabinets. It is externally powered by 24 VAC/VDC, providing low power consumption and installation flexibility.
- Industry-Standard Outputs – Outputs such as 4-20 mA, 0-5 VDC, and 0-10 VDC ensure seamless integration with PLCs, SCADA systems, and other automation and control systems.
- Global Certifications – UL/cUL listing and CE certification ensure the VT3-OS Series meets international safety and performance standards for use worldwide.
About NK Technologies
NK Technologies has more than five decades of experience designing and manufacturing high-performance sensing products for industrial, commercial, and OEM applications. Known for robust engineering, reliable performance, and exceptional customer support, NK Technologies continues to set industry benchmarks for electrical sensing solutions.
Introducing the VT3-OL Series AC Voltage Transducer for 120 VAC-Powered Three-Phase Monitoring up to 600 VAC
San Jose, CA — NK Technologies is pleased to announce the launch of the VT3-OL Series AC Voltage Transducer, engineered for precise three-phase voltage monitoring in applications where 120 VAC power is the preferred supply.
The new VT3-OL Series complements NK Technologies’ VT3 family of True RMS voltage transducers by offering a robust solution tailored for systems powered by standard line voltage, expanding the flexibility of voltage-sensing options for industrial automation and control systems.
Key Features & Benefits:
- True RMS Three-Phase Voltage Monitoring — The VT3-OL accurately measures three-phase voltages in common ranges (120, 240, and 480 VAC up to 600 VAC) for reliable system monitoring and control in three-phase electrical environments.
- Phase Loss Detection with Relay Output — Built-in phase loss detection with an SPST Form A relay provides additional diagnostic capability, helping operators identify undervoltage or missing-phase conditions that could damage equipment or reduce system uptime.
- Industry-Standard Analog Outputs — Available with 4–20 mA, 0–5 VDC, or 0–10 VDC outputs, the VT3-OL easily interfaces with PLCs, SCADA systems, and building management controllers.
- 120 VAC External Power Supply — Powered directly from 120 VAC, the VT3-OL eliminates the need for separate low-voltage power supplies in many installations — a key advantage in retrofit or utility-powered environments.
- Flexible Mounting Options — With both DIN rail and panel mount housings, the VT3-OL installs easily in a wide range of electrical panels and enclosures.
- Global Safety Certifications — UL/cUL listing and CE certification ensure compliance with international safety and performance standards.
How the VT3-OL Differs from the VT3-OS:
The VT3-OL is designed for 120 VAC supply power, making it ideal for systems where line power is readily available or preferred. In contrast, the VT3-OS Series is optimized for 24 VAC/VDC power, offering greater flexibility in low-voltage control environments and applications where 24 V supplies are standard.
About NK Technologies
With more than five decades of experience designing and manufacturing industry-leading electrical sensing products, NK Technologies delivers solutions trusted for performance, durability, and precision across global automation, energy, and industrial markets.
NK Technologies Unveils Latest Product Catalog
San Jose, CA – NK Technologies has released its updated 2025 Product Catalog, providing engineers and system designers with a comprehensive resource covering the company’s full range of current, voltage, power, ground fault, and sensing products.
The new catalog combines performance data, detailed specifications, dimensional information, and application guidance for NK’s expanding portfolio of solutions used in industrial, automation, and commercial environments.
What You’ll Find Inside:
- Current sensing products including AC and DC transducers, sensing switches, and indicators.
- Voltage and power transducers with True RMS measurement and analog outputs for monitoring and control.
- Ground fault protection devices and application guidance.
- Technical specifications, performance charts, and installation reference material.
Featured in the new catalog are recently-introduced products:
- AGL-MAR Series — ground fault relays built for marina applications
- VT3-OS/OL Series — AC voltage transducers for reliable voltage monitoring for three-phase applications up to 600 VAC
This updated catalog reflects NK Technologies’ continued commitment to innovation and breadth of product offerings, showcasing the latest sensing and protection devices engineered for accuracy and reliability across diverse applications. With flexible mounting options, industry-standard outputs, and UL/cUL/CE certifications, the catalog provides essential information to help specifiers choose components that meet performance, safety, and integration requirements.
About NK Technologies
NK Technologies has been advancing electrical sensing technology since 1982 and is recognized for reliable, high-performance current, voltage, and power products used across factory automation and industrial power monitoring applications.
The Industrial and Commercial Canary in a Coal Mine
Motors are used everywhere in industrial and commercial automation applications. Various means are available to determine whether a motor is running, such as an indicator light connected to the motor power input. However, knowing that a motor is operating optimally and within specifications requires a different approach.
Motors have shaft bearings, and those bearings will wear over time. The source of a motor failure, such as bearing wear, can be used to provide an early warning of impending failure. A power transducer or current transducer can help prevent equipment damage and unplanned downtime by providing advanced warning that a motor might fail or is overloaded.
Early Warning Methods
Years ago, in the hard coal mining industry in Pennsylvania, long before gas detection devices were available, miners would carry a canary deep into the coal mines with them. They would keep an eye on the canary to determine whether harmful gases such as carbon monoxide were present in the mine. If the canary collapsed, it was the miners’ early warning to evacuate the mine shaft until the source of the toxic gas could be located and eliminated before they, too, fell victim.
A power or current transducer can be used in much the same manner as the canary once was. Transducers can be used to create an early warning that then can be used to investigate a potential problem’s source well before a catastrophic event occurs. Think of it as an “electronic problem detecting canary in a coal mine.”
As motor bearings wear, the motor will work harder to overcome the increased resistance associated with shaft bearing wear. The effect of increased resistance is reflected in the current a motor is drawing.
As the bearings wear, the motor current draw will increase proportionally. A power or current transducer installed on one conductor of an AC motor can be used to monitor the motor’s current draw. The current transducer’s analog output can be connected to a programmable logic controller’s (PLC’s) analog input card. The PLC can, in turn, be programmed to issue an alert or sound an alarm when the motor current exceeds the motor current draw associated with an optimally functioning process.
NK Technologies Releases New Ground Fault Detection Tech Guide
San Jose, CA – NK Technologies (www.nktechnologies.com) has released a new educational resource for engineers. The Ground Fault Considerations Tech Guide covers a wide range of topics and includes an easy-to-use selection guide, as well as a variety of case studies and application examples.
Highlights include:
- Ground fault detection basics
- Ground fault sensing basics
- Consolidated ground fault sensors selection guide
- Case studies
- Application examples
- Design considerations for earth fault protection
ABOUT NK TECHNOLOGIES
Founded in 1982, NK Technologies designed the first low-cost solid-state current sensing technology that underlies the industry today.
Today, NK Technologies is a leading provider of current sensing, ground fault detection and power monitoring products to the industrial and factory automation markets, with a product portfolio that includes more than 1300 models to satisfy a wide range of specific application needs. As the needs of these markets change, NK Technologies is well-positioned to respond with sophisticated new product designs and improved product functionality necessary to meet
AG-LC Series Ground Fault Sensor: New Large Solid-Core Design Ideal for Monitoring Larger Circuits
SAN JOSE, CA – NK Technologies announced the AG-LC Series, a new ground fault sensor that makes it easy to monitor larger circuits. The 2011 NEC requires ground fault protection of the main over-current device feeding marinas and boatyards, where these services often carry up to 800 amps. Most sensor designs do not allow the conductors to pass through a single sensing ring, requiring a separate sensing device such as a zero-sequence current transformer. The AG-LC Series resolves this issue with an innovative large solid-core housing design that provides ample space for multiple conductors to pass easily through one sensing window.
Key applications include:
- Monitoring large machines: Detecting leakage to earth before the problem can cause damage
- Water treatment and delivery: Keeping pumping systems safe and in operation
- Generators: Shut down equipment when leakage current exceeds hazardous levels
AG-LC Series highlights include:
- Electromechanical relay output provides both normally open and normally closed contacts
- Compatible with most automation and control systems
- Externally powered – choice of fail-safe or standard operation
- Simple field setpoint adjustment
- Adjustable time delay
- DIN Rail or panel mount
ABOUT NK TECHNOLOGIES
Founded in 1982, NK Technologies designed the first low-cost solid-state current sensing technology that underlies the industry today.
Today, NK Technologies is a leading provider of current sensing, ground fault detection and power monitoring products to the industrial and factory automation markets, with a product portfolio that includes more than 1300 models to satisfy a wide range of specific application needs. As the needs of these markets change, NK Technologies is well-positioned to respond with sophisticated new product designs and improved product functionality necessary to meet
AGT-FD Ground Fault Sensor: Large Sensing Window Makes Monitoring 100 A Circuits Easy
SAN JOSE, CA – NK Technologies (www.nktechnologies.com) released the AGT-FD Series, new ground fault sensors that detect faults to earth from 0 mA to 100 mA and produce an output signal of 0–10 VDC in proportion to the amount of current passing to ground. The output is equal to the RMS value of the earth leakage. The AGT's sensing window is large enough to monitor 100 amp circuits. It can also be used to measure and monitor any low-value AC circuit current by passing just one of the conductors through the sensing window.
The AGT-FD Series is ideal for monitoring earth leakage current for applications including: electric heating processes, AC motor loads, semiconductor wafer fabrication, plastic molding processes, heat trace cable systems, and snow melt protection.
Features include:
- Analog output signal, 0–5 or 0–10 VDC proportional to 0–100 mA
- Externally powered, 24 VAC or DC(20-30V)
- Factory calibrated, warrented to stay accurate for minimum of 5 years
- Panel mount or simple snap onto DIN rail
ABOUT NK TECHNOLOGIES
Founded in 1982, NK Technologies designed the first low-cost solid-state current sensing technology that underlies the industry today.
Today, NK Technologies is a leading provider of current sensing, ground fault detection and power monitoring products to the industrial and factory automation markets, with a product portfolio that includes more than 1300 models to satisfy a wide range of specific application needs. As the needs of these markets change, NK Technologies is well-positioned to respond with sophisticated new product designs and improved product functionality necessary to meet
New DT-FD Series DC Current Transducer from NK Technologies Monitors Circuits with Voltages Up to 1500 VDC
SAN JOSE, CA – NK Technologies (www.nktechnologies.com) introduces the DT-FD series DC Current Transducers. The DT-FD series provides a large sensing window and the ability to safely monitor circuits with voltages up to 1500 VDC, and up to 400 amps. The sensor can be mounted on a DIN rail or attached to a back panel with screws. The easily accessible power supply, output-signal, and finger-safe terminals are located on the top of the sensor to allow for a clean and trouble-free installation. The DT-FD’s one-piece design combines the current sensing elements and the signal conditioning to provide an output compatible with most control systems, increasing the safety and accuracy of the installation.
Features include:
- Industry standard analog output
- Externally powered 24 VAC or DC
- Factory-set calibration reduces setup time
- Large sensing window with ample space for single or multiple conductors
- Designed for UL, CUL and CE approval for use worldwide
The DT-FD is ideal for applications such as monitoring large solar panel installations, motors in traction and drilling equipment, uninterruptible power supplies (UPS), and telecommunication towers, among many others.
ABOUT NK TECHNOLOGIES
Founded in 1982, NK Technologies designed the first low-cost solid-state current sensing technology that underlies the industry today.
Today, NK Technologies is a leading provider of current sensing, ground fault detection and power monitoring products to the industrial and factory automation markets, with a product portfolio that includes more than 1300 models to satisfy a wide range of specific application needs. As the needs of these markets change, NK Technologies is well-positioned to respond with sophisticated new product designs and improved product functionality necessary to meet