Application Orientated News Story Energy Management 24/6/2010
G7L and G8P relays ideal for renewable energy applications play a principal role in effective energy management, ensuring that systems or sub-systems are fully powered down and use no energy when they are not in use. The power efficiency of a system can be notably influenced by the way in which power is switched and applied. Many emerging renewable energy based systems, however, have characteristics that are not well served by existing switches, such as frequent, long term switching of higher DC currents. At the same time, the relays themselves consume energy during switching, which can be minimised by good design.
Omron has developed two new relays starting from the existing product families G7L and G8P, specifically to meet the needs and requirements of renewable energy systems. Many of these systems will require efficient DC-AC inverter circuits where robust and reliable relays must be capable of handling AC load switching and providing network grid isolation protection.
Relays in the inverter must use minimal coil power during continuous closed contact operation as minimising power loss in the inverter is essential to prevent excessive temperature rise and efficiency losses. Renewable power applications will therefore demand durable power relays capable of switching loads of up to 30A, providing a large >1.5mm contact gap to ensure dependable load isolation, a mechanical endurance in excess of 30,000 switching operations and a low coil hold ‘on’ power.
The new Omron G7L relay features a sealed, PCB mounting package with mechanical dimensions of 52.5mm (l) x 35.5mm (w) x 41.0mm (h). The G7L provides a durable switching relay solution with two 30A load contacts, a contact gap of >3mm for each contact and a low coil hold on voltage of 4.5V. Voltage loads of up to 280V can be supported. 
With a power rating of 5000VA the new Omron G8P is a compact, plastic sealed housing relay, suitable for PCB or panel mount applications. The G8P is capable of switching a maximum current load of 20A or a maximum AC voltage of 250V. Featuring a 2.0mm contact gap, the G8P relay is available in an industry standard PCB mounting package with dimensions of 32.1mm (l) x 27.2mm (w) x 20.1mm (h).
Both relays have an operating temperature range of -25° to +85° and have VDE and UL/CSA ratings approval.
Omron is making a significant effort to improve the efficiency of relays where the key characteristics of switching capacity, switching endurance, coil type, load isolation and physical construction can have a notable impact on the overall energy efficiency of a system. New relay families will address the characteristics of new classes of applications that are emerging from the drive for renewable energy use.