Relay_project - AC type A155F-3 Please use Select...

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KRISHNA CHAITANYA NUTUKURTHI EE-641Y (ENT472) Line Overcurrent Protection Project For 13.2 kV feeder below, please, perform the following design and analysis: 1. Determine load currents and line section currents. 2. Verify that the voltage at the head of the feeder is within 5% if the voltage at the end of the feeder (at bus 5) is 13.2 kV. 3. Calculate 3-phase fault currents at all busses if available SCA MVA at the source is 150 MVA and transformer nameplate X = 5.5%. Lines are constructed from ACSR 336.4 MCM with the following parameters: R = 0.271 Ohm/mile and X = 0.445 Ohm/mile. Faults are designated with X on the figure below. 4. Load to the right of bus 5 is protected by a fuse. Fuse is Ferraz-Shawmut, 15500V
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Unformatted text preview: AC, type A155F-3. Please, use Select- a-Fuse (SAF) program for time-current characteristics of this fuse. 5. Select current transformers for busses 4, 3, 2, 1, and Station. 6. Perform selection and coordination of 50/51 overcurrent relays at abovementioned busses. Coordinate relay at bus 4 with the fuse at bus 5. 7. Check your selection for dependability. 8. Make conclusions. Loads at busses, MVA Bus 1 Bus 2 Bus 3 Bus 4 Bus 5 2.5 3 2.5 2.5 1.5 Distances between busses, miles: S-1 1-2 2-3 3-4 4-5 0.5 0.5 1.25 1.0 1.5 138kV Transformer 138-13.2kV 15MVA X=5.5% Station 1 2 3 4 5 Fuse Load at 1 Load at 2 Load at 3 Load at 4 Load at 5 X X X X X X...
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