JND 040 JVS Numerical Transformer Differential Relay

JND 040 provides differential protection for power transformer. The relay measures the line current of each phase from each of the windings of the transformer. Relay calculates the differential current (Id) and restraining current (Ir) per phase. The differential characteristics define the operating and the restraining regions. The shape of the characteristics defined by Initial pickup (ik), SLOPE1 (DF1), SLOPE2 (DF2) and break point (kp) are programmable. If ‘Ir’ is less than ‘kp’, then characteristics is defined by ‘DF1’ and is applicable for small differential currents.