top versus Ipros characteristics of three protective devices 10-AMCB, 15-A MCB and 40-A fuse are shown in the figure. (a) Provide the value of Ipros current at which discrimination fails between 10-A MCB and 40-A fuse and also between 15-A MCB and 40-A fuse. (b) Short circuit breaking capacity of 10-A MCB is 3-kA, of 15-A MCB 4-kA and of 40-A fuse is 8-kA. For 12-kA short circuit at the downstream side of the installation, whether back-up protection possible or not between 10-A MCB and 40-A fuse, and also between 15-A MCB and 40-A fuse. Fill in the table given below for your answers.

Q4(20) top versus Ipros characteristics of three protective devices 10-AMCB, 15-A MCB and 40-A fuse are shown in the figure. (a) Provide the value of Ipros current at which discrimination fails between 10-A MCB and 40-A fuse and also between 15-A MCB and 40-A fuse. (6) Short circuit breaking capacity of 10-A MCB is 3-KA, of 15-A MCB 4-kA and of 40-A fuse is 8-kA. For 12-kA short circuit at the downstream side of the installation, whether back-up protection possible or not between 10-A MCB and 40-A fuse, and also between 15-A MCB and 40-A fuse. Fill in the table given below for your answers. 102 40A t 10 A 15 A op IT 10 10 AX X 15 A .1 .0.1 0.01 1 10 102 103 104 105 I pros Discriminated PDS Discrimination fails at Ipros (A) Back Protection (Possible or Not) 10-A MCB and 40-A Fuse 15-A MCB and 40-A Fuse