OMRON Corporation (Headquarters: Shimogyo-Ku, Kyoto. President and CEO: Yoshihito Yamada) has announced the launch of a new high-voltage DC relay “G9KB” for high-capacity household energy storage systems worldwide.

OMRON aims to contribute to a decarbonised society by expanding its product range, including G9KB, with low energy consumption for energy-saving equipment. G9KB safely interrupts direct current in storage systems of households whose capacity is increasing. It also plays a role in promoting renewable energy by reducing the size of products.


“G9KB” high voltage DC relay supporting 600 VDC / 50A (L 50.5 mm x W 37.0 mm x H 50.5 mm)

Recently, there is a growing need for electricity storage systems to achieve carbon neutrality and to enforce resilience to natural disasters. Therefore, the capacity of household batteries, which are aimed at the internal consumption of electricity generated by the solar energy production system, is increasing. In order to achieve high capacity, the challenge is to ensure the safety of products and parts to reduce size.

OMRON is working on a technology that connects and switches electricity safely and securely, and this high-voltage DC relay “G9KB” comes with the same. By adopting the arc interruption technology * 1 and the new 3D arc simulation technology, created by the collaboration of industry and academia, the relay manages the charging of the power storage system, control of switching and safe disconnection of direct current, which runs during dilution. In 3D arc simulation technology, OMRON has developed a method to analyze the safe interruption process of high-voltage DC and to reflect the result of the analysis to the design of the component structure. With these technologies, the compact high-voltage DC relay is realized, which safely and safely interrupts direct current and ultimately contributes to reducing the size and weight of the customer’s products.

OMRON strives to create new solutions with a focus on cutting-edge devices and modules. These solutions are offered worldwide and aim to work to realize a decarbonised society through products and customer services.

Basic applications

Main features of “G9KB”

High capacity DC relay supporting DC power supply applications

• Connection and disconnection 600 VDC / 50A; supports equipment and applications that open / close high DC loads.

• Safety standards (UL60947-4-1, EN61810-10) required for the components of the solar energy system and the acquired components of the electricity storage system. G9KB simplifies the procedure for applying for customer product safety standards.

Contribute to reducing the size and energy savings of customers’ products

• In the 600 V high voltage system, DC switching control and safe shutdown are achieved with a single relay.

• Compared to one-way relays with equivalent functions, the bottom of the board is reduced to approximately 75% * 2.

• Compared to one-way relays with equivalent functions, coil consumption is reduced to approximately 60% * 3.

Combinations of these technologies achieve both high levels of safety and size reduction.

• By using the magnetic field generated by the permanent magnet located near the contact point, the arc discharge * 4 between the relay contacts in the DC break is extended. With this arc-breaking technology * 1, high-capacity direct current can be cut off safely and securely.

• By using 3D arc simulation technology generated in collaboration between industry and academia, the speed and quality of design and technology verification is improved. By visualizing the arc phenomenon, the process of interrupting the arc inside the relay is simplified and a reduction in the body size of the component is realized.

Basic specifications of “G9KB”

Thing G9KB
Contact configuration 1a
Contact Gap > 3.6 mm
Contact resistance ≤5 mΩ *5
Rating 600 VDC / 50A (resistive load)
Electrical service life (resistive load) ± 2,000 times at rated load (Switching frequency: 1 second ON – 9 seconds OFF at 85 ° C, 25 to 75% RH) The recommended Zener diode voltage is 3 times higher than the rated voltage.
Polarity of the main contact None
Mechanical service life 1,000,000 times (Switching frequency: 10,800 times / h)
Coil voltage 12 VDC / 24 VDC (Voltage retention: 45 to 60%)
Coil power consumption Approx. 2.8 W (Retained voltage: At 45%: 0.57 W)
Work temperature -40 to + 85 ° C
size L 50.5 x W 37.0 x H 50.5 mm
terminal printed circuit boards
structure Flux resistant
Safety standard UL60947-4-1, EN61810-10, CQC

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* ¹ Arc Break Technology: A technology that breaks the arc generated between contacts when the relay contact is opened, using the magnetic field of the permanent magnet located near the contact.

* 2 Reduced to approx. 75%: Investigation in the company in May 2022

* 3 Reduced to approx. 60%: in – house investigation in May 2022

* 4 Arc Discharge: An arc is an electrical discharge in the air by increasing electrical conductivity due to the dissociation and disaggregation of gas molecules at high air temperatures, such as several thousand degrees or higher. * 5 Contact resistance ≤5 mΩ: Measuring condition 6 VDC, 20 A (after 30 seconds) Voltage drop method

OMRON Launches “G9KB” Relay for High-Capacity Electricity Storage Systems, Contributing to Realization of a Decarbonized Society with its ” Switching Technology”