Secondary MV protection

The numerical relays SPR10, powered by the current transformers (CTs), do not require an external power supply voltage. They are the ideal choice for installation in remote locations where auxiliary supply is not available. Two input circuits of residual current are available in order to insert or exclude the residual current from the power supply circuit. When the protected circuit is de-energized the operating status (rest / trip) is signaled by means of a mechanical indicator fl ag.


Standard Protective & control elements
  • Phase overcurrent side H and side L - 50/51
  • Maximum Residual Overcurrent - 50N/51N
  • Negative sequence overcurrent transformer - 46LT
SW Pack optional configuration
  • Thermal Image Transformer - 49LT