OMRON reveals 300A/1000V power relay with auxiliary contact for diagnostics

OMRON Electronic Components Europe has introduced a 300A 1000V relay with auxiliary contact, delivering a PCB-mount alternative to high-current electromagnetic contactors in systems for power conversion and control.

Relays in the 30A-300A range are becoming more widely chosen in preference to conventional contactors in industrial automation and electrification projects. Designers are opting for their compact dimensions and fast, efficient on-board assembly with soldered connections, to deliver systems that are more affordable, usable, and reliable.

The G9KA-1A1B-E from OMRON is among the first high-current relays in the market to provide an auxiliary connection, commonly provided in contactors. The auxiliary mirrors the main contact to fulfil roles such as a safety indicator, interlock controller, sequencing trigger, or logic signal for interacting with external systems. With these features, the G9KA-1A1B-E is suited to safety and control switching in industrial, utility, and general power-conversion markets. Applications include industrial inverters, inverters for solar generators and energy storage systems (ESS), fast chargers for electric vehicles (EVs), power supply units (PSUs), and uninterruptible power supplies (UPS).

The single-pole single-throw (SPST) relay main contact is normally open (NO). The 1A/30V auxiliary contact is normally closed (NC) and opens when the main contact is activated. The main switch has initial resistance below 0.2mΩ, helping preserve system efficiency and minimizing internal heat generation. Also featuring a high-dissipation internal structure, the G9KA-1A1B-E ensures outstanding reliability and minimal PCB temperature rise in sustained high-power operation.

Designed with a contact gap of at least 4.0mm, the G9KA-1A1B-E meets the German industry standard for automatic grid-disconnection devices in photovoltaic installations, specified in VDE 0126. The auxiliary contact meets the international safety standard IEC/EN 60947-4-1 and ensures high reliability, with bifurcated terminals and a minimum rated lifetime of 100,000 operations.

The G9KA-1A1B-E expands OMRON’s family of high-power board-mount relays that now includes a total of eight variants spanning ratings from 40A to 300A, 250V to 1000V. With a maximum current and voltage of 300A and 1000V, the G9KA-1A1B-E has the highest rating, equivalent to the G9KA-1A-E single-channel relay, and is the first in the family above 50A to feature the auxiliary contact.