Pick up & Drop off Test for Differential current (Id) The diff equation for single phase injection, 2 windings will be And after applying zero sequence removing facility then, KH.V = ---------- KL.V= ----- H.V. Winding fault Id Min Calculated Measured value (A) Drop out Operating Time @ type set value value (A) pick up Ratio 2.5x I pick up (ms) Pick up Drop out R-N Y-N B-N R-Y Y-B B-R R-Y-B L.V.Winding: fault Id Min set Calculated Measured value (A) Drop out Operating Time @ type value value (A) Pick up Drop out pick up Ratio 2.5x I pick up (ms) R-N Y-N B-N R-Y Y-B B-R R-Y-B Pick up & Drop off Test for unrestrained Differential current (Id)
Pick up & Drop off Test for Differential current (Id) The diff equation for single phase injection, 2 windings will be And after applying zero sequence removing facility then, KH.V = ---------- KL.V= ----- H.V. Winding fault type Id Min set value Calculated value (A) Measured value (A) Drop out pick up Ratio Operating Time @ 2.5x I pick up (ms) Pick up Drop out R-N Y-N B-N R-Y Y-B B-R R-Y-B L.V.Winding: fault type Id Min set value Calculated value (A) Measured value (A) Drop out pick up Ratio Operating Time @ 2.5x I pick up (ms) Pick up Drop out R-N Y-N B-N R-Y Y-B B-R R-Y-B Pick up & Drop off Test for unrestrained Differential current (Id)