Large Jaw DC/AC Clamp Current Meters and Ultra-Large Aperture Clamp Meters for Heavy Industrial Applications

Large Jaw and Ultra-Large Aperture Clamp Current Meters for Heavy Industrial Use

Standard clamp meters with jaw openings of 25-35mm work well for most residential and light commercial wiring. However, industrial power distribution systems frequently use conductors that far exceed these dimensions — large-diameter cables, multi-conductor bundles, bus bars, and heavy-duty feeders that require clamp meters with significantly larger jaw openings. EK Instruments offers a range of large jaw and ultra-large aperture clamp current meters specifically designed for these demanding measurement scenarios.

The Need for Larger Jaw Openings

Industrial facilities distribute power through conductors sized for hundreds or thousands of amperes. Bus bars in main distribution panels can be 50mm or more in width, power cables for large motors and equipment can exceed 70mm in diameter, and cable bundles feeding multiple circuits may require jaw openings over 100mm. Attempting to use a standard clamp meter on these conductors is physically impossible — the jaws simply cannot open wide enough to encircle the conductor.

Beyond physical access, large-diameter conductors often carry DC current as well as AC, particularly in applications involving battery systems, rectifiers, DC motor drives, electrolysis plants, solar power systems, and electric vehicle charging infrastructure. DC current measurement requires Hall effect sensing technology rather than the current transformer technology used in AC-only clamp meters, adding technical complexity to the instrument design.

Large Jaw DC/AC Clamp Current Meters

The EK-G667D features a 70mm diameter circular jaw opening and measures both DC current (0.0A to 2000A) and AC current (0.0A to 1500A). True RMS measurement ensures accuracy with distorted AC waveforms, and max/min recording captures peak values during motor starting and load transients. The Bluetooth wireless connectivity enables real-time data streaming to smartphones, while the rechargeable lithium battery provides consistent performance throughout long workdays. A built-in flashlight and backlit display enhance usability in dark industrial environments.

The EK-G668D steps up to an 80×80mm rectangular jaw opening that accommodates wider bus bars and larger cable bundles. With DC current measurement up to 2000A and AC measurement up to 1000A, it serves the same high-current applications while fitting around broader conductor profiles. Like the EK-G667D, it features true RMS, max/min recording, Bluetooth, and lithium battery power.

Ultra-Large Aperture Clamp Meters: EK-H710 Series

For the largest conductors and bus bars found in heavy industrial and power utility applications, the EK-H710 series provides jaw openings measuring 108×148mm — large enough to encircle virtually any single conductor or bus bar configuration.

The EK-H710 is an AC leakage current and current meter with a measurement range from 0.0mA to 3200A. Its milliampere-level sensitivity combined with kiloampere-level range makes it uniquely capable of measuring both tiny leakage currents and full load currents on the largest conductors. This dual capability is valuable for comprehensive cable assessment — measuring both the load current (to verify the conductor is within its rated capacity) and the leakage current (to assess insulation health) using the same instrument. USB connectivity enables data transfer for analysis and documentation.

The EK-H710A is the current-only version with a range from 0.0A to 4000A, optimized for load current measurement on the heaviest industrial feeders. Without the milliampere leakage current sensitivity of the H710, it focuses on delivering accurate high-current readings for load verification, capacity assessment, and circuit loading analysis.

The EK-H710D adds DC measurement capability to the ultra-large aperture platform, measuring DC current from 0.0A to 2000A and AC current from 0.0A to 1000A. This model serves applications where both DC and AC currents flow through large conductors, such as in electrochemical plants, large UPS systems, DC traction power systems, and hybrid AC/DC distribution networks. USB connectivity supports data management and reporting.

Applications Across Industries

Large jaw clamp meters serve critical measurement needs across multiple industrial sectors. Power generation plants use them to measure current on generator output bus bars, auxiliary power feeders, and station service circuits. Manufacturing facilities rely on them for monitoring arc furnace electrode current, large motor feeders, and main bus distribution systems. Metal smelting and electrochemical plants measure DC currents on bus bars carrying thousands of amperes to electrolytic cells.

Data centers use large jaw clamp meters to measure current on main power distribution bus bars, UPS output feeders, and generator connection cables. Renewable energy installations measure inverter output current, DC bus current in large battery storage systems, and transformer secondary feeders. Marine and shipboard electrical systems feature large cables in confined spaces where ultra-large aperture clamp meters provide the only practical measurement solution.

Choosing the Right Large Jaw Clamp Meter

Selecting the appropriate large jaw clamp meter requires matching the jaw size to the largest conductor you need to measure, the current range to the maximum current you need to read, and the measurement type (AC only, DC only, or AC/DC) to your application requirements. The EK-G667D and EK-G668D provide excellent DC/AC capability for conductors up to 80mm, while the EK-H710 series handles the largest conductors with jaw openings exceeding 100mm.

Conclusion

Large jaw and ultra-large aperture clamp current meters from EK Instruments solve the measurement challenge of oversized industrial conductors. From the versatile EK-G667D for DC/AC measurement on large cables to the massive EK-H710 series for bus bars and heavy feeders, these instruments deliver accurate current measurement where standard clamp meters cannot reach. Equip your maintenance team with the right large jaw clamp meter for reliable measurement in every industrial environment.