The total impedance of the secondary winding, leads, and burden of a 5A CT is . If the fault current is 20 times the rated primary current of the CT, the VA output of the CT is_____________.

A 3-phase transformer rated for 33 kV/11kV is connected in delta/star as shown in figure. The current transformers (CTs) on low and high voltage sides has a ratio of 500/5. Find the currents  and, if the fault current is 300 A as shown in figure.

In a biased differential relay, the bias is defined as a ratio of

In the protection of transformers, harmonic restrain is used to guard against

Match the following

A three-phase delta-wye connected 30MVA, 33 kV/11 kV transformers is protected by a simple differential relaying scheme. The CT ratio on the primary side is 500: 5 and that on the secondary side is 2000: 5. Sketch the CT connection diagram for the relaying scheme. Also calculate the relay current setting for faults drawing upto 200% of the rated current.

A Buchholz relay is used for

Match the following

A 50 MVA, 132/66 kV, , three phase power transformer is protected by percentage differential relays. If the current transformers (CTs) located on the delta and wye sides of the power transformer are 300/5A and 1200/5A respectively.