If you have questions about our products, Fill out the form below and we will answer any questions you have. Tips: Fields marked with*are required. ABB REJ603 REJ603BB401NN3XE Grounding Protection Relay Introduction The ABB REJ603 REJ603BB401NN3XE Grounding Protection Relay is a compact, self-powered protection device engineered for secondary distribution networks, Ring Main Units (RMU), and unmanned substations. Designed under ABB’s Rel *Your Name: *Your Email: *Your Name: *Vdcode: Submit