When Protective Relay Indicator Module receives fault indication from any of 4 transformer relays, it identifies offending relay on LED display and trips lockout relay. In dual-supply/single-transformer or dual-supply/dual-transformer scheme, device monitors transformer differential, sudden pressure, time/instantaneous overcurrent, and instantaneous ground relays, isolating transformer from source when fault occurs. In capacitor bank protection scheme, it checks overvoltage, undervoltage, time/instantaneous overcurrent, and neutral overvoltage, isolating capacitor bank from source when fault occurs.