REU615 is a voltage protection and control relay for voltage and frequency-based protection in utility and industrial power distribution systems, including networks with distributed power generation. Multiapplication coverage combined with a fully. CHAPTER – 3 ELECTRICAL PROTECTION SYSTEM 3. 1 DESIGN CONSIDERATION Protection system adopted for securing protection and the protection scheme i. the coordinated arrangement of relays and accessories is discussed for the following elements of power system. REU615 is a member of ABB's Relion ® product family. The 615 series of relays provides a number of standard configurations and is the ideal choice for a great variety of applications within distribution protection and control. Are you looking for support or.