High-current DC relay for safety-critical power isolation

OMRON Electronic Components Europe has expanded its DC power relay portfolio with the G9EK-1-EX, a normally open relay designed for safety isolation and high-current switching in electric-vehicle charging infrastructure, renewable energy systems, and e-mobility applications.

Technical context and application relevance
The increasing power levels in DC-based systems such as EV chargers, battery storage, and industrial electric mobility require compact switching components capable of handling high currents while maintaining electrical and mechanical robustness. The G9EK-1-EX addresses these requirements by providing higher switching capacity within the established G9EK screw-terminal form factor.

Electrical performance and efficiency
The G9EK-1-EX is rated for 250 A at 500 VDC, extending the performance range of the G9EK-1 series beyond the 200 A capability of the G9EK-1-E variant. An optimized internal structure achieves a contact resistance of 15 mΩ when closed, helping to limit conduction losses under high load conditions.

Coil power consumption is specified at 4 W, reducing thermal dissipation compared with conventional high-current contactors. The relay maintains the same compact outline as other G9EK-1 devices, measuring 47.7 mm × 86 mm × 64.2 mm, supporting space-efficient designs in densely populated power assemblies.

Mechanical robustness and reliability
The contact mechanism of the G9EK-1-EX is engineered to withstand mechanical stress in demanding environments. The relay tolerates shock loads up to 100 g, supporting use in applications such as industrial automated guided vehicles (AGVs) and mobile electric platforms.

In addition, the terminal structure is designed to suppress magnetic repulsive forces generated by high currents, particularly during abnormal conditions such as short circuits. This design approach contributes to improved durability and extended operational lifetime.

High fault tolerance and insulation strength
For safety-critical applications, the relay supports interruption currents up to 1000 A at 400 V and withstands voltage impulses of up to 4000 V. These characteristics increase the safety margin in high-energy DC systems.

The G9EK-1-EX uses a gasless design, simplifying the internal architecture while supporting safe operation and alignment with carbon-neutral product strategies.

Switching behavior and service life
The relay provides an operating time of 50 ms and a release time of 30 ms, enabling predictable switching behavior in control and protection circuits. Mechanical endurance is rated at 200,000 operations, supporting long-term deployment in systems with frequent switching cycles.

Technical positioning
With the G9EK-1-EX, OMRON Electronic Components Europe extends the G9EK series toward higher current DC applications, offering a compact alternative to traditional contactors. The combination of increased switching capacity, low power consumption, mechanical robustness, and high fault tolerance makes the relay suitable for safety isolation tasks in modern DC power infrastructures.

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