The SEL-787 Relay is a versatile, two-winding current differential relay that protects industrial transformers. Monitor transformer health with cumulative through-fault current recording, and for the first time in the industry, automatically check and generate differential compensation settings with the Commissioning Assistant Software.
Provide complete current differential and overcurrent protection for three- and four-winding transformers. Select the SEL-787-3E or SEL-787-3S for current- and voltage-based protection on three-terminal transformers, and choose the SEL-787-4X for current differential and overcurrent-based protection on four-winding transformers.