Passive Component or Electromechanical Product of the Year
Company Name: OMRON Electronic Components Europe
Product Name: G9KD PCB Power Relays
Supporting Statement:
OMRON G9KD Contactor Replacement Relays
The right product at the right time
As utility-grade energy storage and fast EV chargers form the foundations of our electrified future, the world needs technical solutions that are safe, reliable, economical, and easy to live with. OMRON’s new G9KD high-current DC power relays are here to meet the challenge.
Historically, high-energy electrical systems have existed as specialised equipment, produced in relatively low numbers, observing established industry form factors, and deployed within controlled environments. Electric Vehicle (EV) charging infrastructures and distributed energy storage systems are already scaling towards a future that will contain multiple millions of access points. E-mobility, in particular, is pushing high-energy electrical systems into the consumer domain. Here, although user safety must remain the top priority, a competitive purchase price, ease of use, and an unobtrusive external appearance are also critical for market acceptance.
The G9KD series provides isolation and power control meeting safety and reliability benchmarks informed by industrial experience, in a space-saving form factor that’s also economical and compatible with high-volume manufacturing processes.
A safe solution to contactor constraints
OMRON’s new relays present an alternative to electromechanical contactors. Contactors are typically large components, with heavy and slow-moving mechanisms, that are connected to the power circuit using screw terminals. These call for manual assembly, which is laborious, slow, and vulnerable to errors such as incorrect connection or insufficient tightening that can lead to equipment failure. Also, the wires are typically a heavy gauge, which can be difficult and time consuming to work with. As equipment builders experience increasing pressure due to market-volume demand, the risk of assembly errors increases.
The G9KD series leverages OMRON’s expertise in relays and contactors to adopt a Printed Circuit Board (PCB) mount form factor with solderable terminals. Customers can build their assemblies using automated processes and equipment that are suited to high-volume production, thereby reducing production defects while more easily satisfying mass-market demand.
The numbers show
The relays contain a Single Pole Single Throw (SPST) normally open (type 1a) switch, with optional 1b auxiliary, in a 60.5mm x 43.5mm x 56.5mm-high outline. A PCB assembly containing three of these relays can replace a type-3a contactor of comparable rating, saving both physical size and weight.
Their 6mm main-contact gap provides a large isolation distance, while the initial contact resistance of less than 4mΩ minimises energy loss and self-heating.
To handle the power required in DC fast chargers and utility-grade battery energy storage, the relays are designed to handle operating voltages up to 1500V DC.
Importantly, as a safety isolation device, the relays can break contact when carrying 150A, the maximum rated main current. DC arcs are extinguished without using pressurised gas.
As a relay, the G9KD can remain in the ON state with lower coil power by applying a reduced holding voltage after switching; a valuable saving in precious renewable energy terms. The actuation mechanism lets designers use familiar capacitive-charging, resistor-limiting, or Pulse Width Modulation (PWM) holding-voltage techniques.
Installation, uptime, and repair
Street-level DC fast chargers must typically provide multiple outlets to let several users charge their vehicles at the same time. PCB assemblies, as factory-built units containing multiple relays and ready to install in the cabinet with minimal extra wiring, are ideal for these types of applications.
Whereas contactor terminals must be individually connected in situ, installing the PCB assembly is generally faster and easier, requiring fewer connections and hence ensuring greater long-term reliability. Customers have reported that the installation time can be reduced by half.
Also, if field repair is needed during the lifetime of the charger, the PCB assembly can be replaced as a single unit. This simplifies managing spare parts inventory and eases troubleshooting.
Contactor equivalent safety diagnostics
However, there is more to engineering a switch in a relay form factor to handle the role of a contactor. Unlike a load switch, the contactor’s role is primarily as a safety device. It must open to provide galvanic isolation when required and provide a reliable indication that opening has occurred making the equipment safe. This indication is needed to show that the main contacts have not become welded due to the effects of high DC current passing. For this, a contactor usually contains a set of auxiliary contacts that are mechanically linked with the main contacts to mirror their status, whether open or closed.
OMRON’s G9KD series allow fault detection with a single relay by including optional auxiliary contacts for weld detection. These contacts meet IEC/EN60947-4-1, the industry specification for mirror contact structures, and have a rated current of 1.0A. If the main contacts fail to open due to welding, the auxiliary contacts maintain at least 2.5kV impulse-withstand capability, as well as a contact gap of at least 0.5mm, even after the coil is de-energised.
The right product for the future
Bringing together all these features, the G9KD series combines the size reductions, simplified assembly, smaller size, and lower power consumption of a relay with the high current and voltage rating, galvanic isolation, and failsafe detection properties of a contactor.
By displaying the best characteristics of both devices, these relays introduce a new class of component that enables the technically complex high-voltage, high-power systems needed for sustainable lifestyles of the future to be made safe and reliable, as well as easy to use, stylish, and cost-effective.
https://components.omron.com/eu-en/products/relays/G9KD
Entry ID: 7590
