G9EN relay. Click to enlarge.

Omron has been working over the last decade to meet the needs of clean energy car manufacturers for greater circuit design flexibility and components that enable down-sizing and weight reduction of onboard electrical equipment. With the G9EN (60A), Omron is taking down-sizing and weight reduction to the next level. The company is also preparing for the release of other advanced new products including a 150A main relay, and an air-break switch pre-charge relay.

Features of the G9EN DC power relay include:

• 50% reduction in volume (28×40×50mm) and weight (140g) compared with previous Omron models in the same product class.

• Non-polarized contact circuit (contact terminal) (the first model in this class to feature this). This contributes not only to device downsizing and weight-reduction, but also makes wiring and mounting much simpler.

Other main applications include chargers, feeders, and accessories for electric vehicles and plug-in hybrid cars; feeder circuits and condensers for fuel cell cogeneration systems and solar power systems; and industrial equipment (elevators, industrial robots, testing devices, etc.)

DC power relays enclose pressurized gas which enables them to hinder arc formation by cooling. (An arc is a type of discharge which occurs in a gas between electric poles with low voltage and high current. Arcing damages contacts and worsens the interruption characteristics by creating a temporary current flow between contacts resulting in considerable localized heating.)

Typically, a ceramic housing is used to keep the pressurized gas sealed in, but Omron has achieved down-sizing and weight reduction of the relay body by changing the ceramic sealing construction from a conventional box-shaped ceramic case to a combination of ceramic plating and metal casing.

This makes it possible to maintain or increase the interior volume of the air-tight space of the main contact circuit (main terminal) structure compared with existing comparable products.

Omron designed the layout, spacing, and shape of the switching circuit and the permanent magnet circuit specifically to extinguish the arcing which occurs during DC load interruption across narrow contact gaps.

This enables high-speed arc interruption regardless of current direction, and has resulted in a non-polarized main contact circuit (main terminal) which up till now has been difficult to achieve with direct-current type relays using arc interruption via magnetic blow-out.

This non-polarization means the device is suitable for use in applications requiring two-way current flow. It also means it is not necessary to consider the mounting direction or the orientation of the device, making wiring and mounting much easier, and reducing the risk of incorrect wiring.

Omron is targeting annual sales for the Type G9EN in 2013 & 2014 of 500,000 units, and 1 million units from 2015 onwards.