Introduction

As electrification accelerates across industries, reliable high-voltage relays are essential to ensure safe and efficient system operation. Omron’s G9EJH-1P-E pre-charge relay is engineered for demanding applications such as electric vehicle chargers, energy storage systems (ESS), and solar inverters, where large capacitor banks and high inrush currents are common.

This article introduces the technical highlights, advantages, and application scenarios of the G9EJH-1P-E relay.

Why Use a Pre-Charge Relay?

When connecting a battery or low-impedance source to a large capacitor bank, the initial inrush current can be extremely high, potentially damaging the main relay or contactor. A pre-charge relay closes first, allowing current to flow through a resistor to safely charge the capacitors. Only after pre-charge does the main relay close, ensuring system longevity and safety.

Key Features of Omron G9EJH-1P-E

       *  High Switching Endurance

           *  100,000+ operations at 800V capacitive loads

           *  Handles inrush currents up to 30A

       *  Rated Performance

           *  Continuous current: 15A

           *  Short-term overload: 30A for 20s

           *  Contact resistance ≤100 mΩ → low power dissipation

       *  Electrical Safety

           *  Impulse withstand voltage: up to 4,500V

           *  Dielectric strength: 2,500 VAC (contact-to-contact, coil-to-contact)

           *  Insulation resistance: ≥1 GΩ

       *  Compact & Reliable Design

           *  Size: 27 × 31 × 30 mm (PCB mount)

           *  Weight: only 36g

    *  Shock resistance: 490 m/s² (contacts closed)

    *  Operating range: -40°C to +85°C

* Fast Reponse Time    

   *  Operate and release time: ≤30 ms

Applications

The G9EJH-1P-E relay is a versatile component for modern power electronics:

1. Electric Vehicle Chargers (EVSE)

       *  Smooth pre-charging of onboard capacitors

       *  Enhances safety and durability of charging modules

2. Energy Storage Systems (ESS)

       *  Protects power conversion units from damaging surges

       *  Ensures stable battery integration

3. Solar Inverters

       *  Provides controlled capacitor charging in DC-link circuits

       *  Improves long-term reliability in renewable power systems

Advantages for Designers and Engineers

    *  Compact size reduces PCB footprint in high-power modules

    *  Long endurance supports extended product lifecycle

    *  High insulation and dielectric strength meet international safety standards

    *  Cost-effective and reliable alternative to bulky mechanical solutions

Conclusion

The Omron G9EJH-1P-E pre-charge relay is a proven choice for high-voltage, high-reliability applications in EV, ESS, and solar industries. Its combination of compact design, robust endurance, and excellent safety performance makes it an essential component for engineers seeking reliable pre-charge solutions.

At AXTEK, we support global OEM, EMS, and system integrators with original Omron relays and technical expertise. Contact us today to discuss your design needs or request a quotation.