Question

. Q2-Fill in the blanks by correct words/figures. Answer only 7 point (1) An overcurrent relay having a current setting of 125% is connected to a supply circuit through a current transformer of ratio 400/5. The pick-up value will be ............... (2) The pick-up value of a relay is 7.5 A and fault current in relay coil is 30A. Its plug-setting multiplier is .......... • (3) Back-up protection functions when ...... (4) The minimum relay coil current at which the relay operates is called......... (5) A relay performs the function of ..... • (6)Buchholz relay is installed between and conservator (7) Buchholz relay is a ............ relay. (8) A distributor is designed from ........... considerations. (9) The point of minimum potential of a uniformly loaded distributor fed at both ends with equal voltages will occur at . . . 10-In a transmission line, generalized constants ..... are equal ........ and

Answer 1

* (1.) I pick up Current setting * Secondary Current of CoT : 1:255 = 6.25A, (2) Plug setting multiplier PSM = 30 I fault I pickup 471 7.5 (3) when main protection fails or in repair (4) Pick up Current (IP) (5.) Fault detection & Tripping action (6-) Maintank Containing Transformer Oil & Conservator (7) Buchholz relay is gas, oil actuated relay (8.) Voltage drop considerations (primary) (9.) will occur at mid point (10.) Voltage ratio (A) A Current ratio (D) [A=D]