over-current protection relay / over-excitation / for generators / for electric motors



  • Measured/monitored value:

    over-current, over-excitation

  • Other characteristics:

    for generators, for electric motors


Current Differential and Overcurrent Relay
The SEL-387A Current Differential and Overcurrent Relay offers restrained and unrestrained differential protection for two terminals. Second-, fourth-, and fifth-harmonic elements, augmented by the dc element, provide security during transformer energization and overexcitation conditions in a user-defined choice of either harmonic restraint or harmonic blocking. Overcurrent elements provide backup protection that contributes to the versatility of the SEL-387A.