Solve Ground Fault Problems
Associated with VFDs

The EL731 AC/DC Sensitive Earth-Leakage Relay is a revolutionary product that finally solves common ground-fault problems associated with variable frequency drives and is equally applicable to AC, DC, and mixed AC/DC systems. It detects a wide range of earth-leakage currents and can reliably protect a variety of applications including conveyor belts, compressors, pumps and mixers found in harsh environments, such as: mining, oil sands operations, petrochemical and other industrial facilities.



EL731 AC/DC Sensitive
Earth-Leakage Relay

The EL731 is a microprocessor-based AC/DC Sensitive Earth-Leakage Relay that offers complete coverage for all frequencies from 0-6,000 Hz. Its adjustable trip setting provides a wide range of low-level protection and system coordination. In addition, the EL731 has a universal power supply which provides flexibility for numerous applications. Among many other features, the EL731 also offers: 

  • RTD/PTC temperature option
  • Password-protected alarm & trip settings
  • Ability to detect ground faults on grounded DC systems
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Success Story:  EL731 Protects Workers from Electrical Shock


Read on below to learn how the EL731 AC/DC Sensitive Earth-Leakage Relay became a part of one company's corporate safety standard...

A global manufacturing company specializing in packaging solutions and industrial products operates high-voltage equipment and needs to protect employees from electrical shock. The company's equipment also requires monitoring & protection to minimize downtime. It was soon determined that a Littelfuse EL731 AC/DC Sensitive Earth-Leakage Relay was needed. The product is now installed inside the high-voltage equipment and will trip off before a problem arises. The company then implemented the EL731 AC/DC Sensitive Earth-Leakage Relay as a part of their corporate safety standard for monitoring arcs that cause fire hazards in their facilities.



Learn More

Interested in learning more about the EL731 AC/DC Sensitive Earth-Leakage Relay? A variety of resources are available to download by clicking the links below.


Going to Ground - Underground Coal
Littelfuse sales engineer Tyler Klassen examines the various challenges with monitoring ground-faults in high resistance-grounded systems and explains how technology can resolve those challenges in this article from Mining Magazine.

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A new approach to mining earth leakage Protection with medium voltage drives
Reliable detection and limitation of earth currents is crucial to safety in underground mining. The risks and how to mitigate them have been discussed at length in literature. What was not considered in the past is that variable speed drives (VSD) are complex voltage sources which can bypass or disturb the conventional protection equipment. To read more, download the Industrial Electrix article below.

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