Transformer Protection Products

The SEL-487E provides comprehensive protection, metering, monitoring, and automation of power transformer applications with up to five 3-phase restraint current inputs, two 3-phase voltage inputs, and three independent neutral current inputs with restricted earth fault (REF) elements.

Protect and control any two-, three-, or four-winding power transformer with the SEL-387, which provides thermal and through-fault monitoring, and with SELogic^® Control Equations, can detect breaker failure.

Protect power transformers with up to three windings, as well as reactors, generators, large motors, and other multi-terminal power apparatus.

Apply the SEL-387A to protect any two-winding power transformer and perform predictive maintenance based on accumulated through-fault duty (as compared to transformer capability as defined in ANSI Standard C57.109).

Apply economical differential protection for two-winding transformers or any two-terminal apparatus.

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.