ABB's Relion family of protection and control relays for primary distribution offers a wide range of products for protection, control, measurement and supervision of power distribution systems for IEC and ANSI applications – from generation and interconnected grids in primary. ABB's Relion family of protection and control relays for primary distribution offers a wide range of products for protection, control, measurement and supervision of power distribution systems for IEC and ANSI applications – from generation and interconnected grids in primary. Numerical relays are based on the use of microprocessors. The first numerical relays were released in 1985. ABB's. To prevent this from happening more than one million protection and control relays from ABB supervise electricity distribution networks in over 100 countries, enabling the safe and reliable distribution of electric power. The objective of a protection scheme is to keep the power system stable by isolating only the components that are under fault, whilst leaving as much of the network as possible still in operation. ABB's multiapplication protection and control offering covers the full range of basic power distribution applications, provides complete coverage for advanced power generation and distribution. Freely configurable all-in-one protection and control relay Comprehensive feeder management relay Comprehensive generator management relay Comprehensive motor management relay Comprehensive transformer management relay Dedicated load-shedding controller ABB Relays-Online makes finding, selecting.