Transformer Protection

DESCRIPTIONThe relays type SSG are intended for the protection against overloads, short circuits and earth faults in radial networks, ring mains or variable structure networks.The relay features the following characteristics:* directional and not directional functions for both overcurrent and earth fault protections;* phase lock loop circuit with memory of the reference voltage for the directional functions (67);* protection functions and final relays fully programmable;* selectable operation curves with independent or dependent time both for the overcurrent and for the earth fault functions;* direct read-out of all the input quantities by means of digital display on the front panel;* counting of the number of operations performed for each function;* counting of the cumulative switched currents for each pole of the circuit breaker;* storing the values of input quantities corresponding to the eight last operation and trace memory, triggered when trip occours, with pre and post-trigger;* blocking circuit, to perform accelerated protection schemes;* optional digital input circuits;* continuous monitoring of internal circuits;* real time clock with memory backup;* serial communication circuit RS485 with MODBUS RTU protocol.