Abstract: A capacitor bank is provided with a relay protection device having a number of measuring stations for sensing a number of different disturbances associated with the capacitor bank. Each respective primary winding of a number of auxiliary transformers is connected to a respective measuring station. The auxiliary transformers generate signals at the respective secondary windings thereof with each signal having a respective duration and level output for identifying a respective one of the different disturbances. An electrically insulated current transformer transmits output signals representative of the auxiliary transformer signals to a number of sensing relays each having a respective tripping time and signal level response such that the particular disturbance can be identified.