Rf-2: - Source end O/C E/F settings calculations for radial EHV feeder.

       132kV Substation-B is being feed by 132kV single circuit radial line A-B End A CT Ratio is ??/1 Amp. Conductor used for line has thermal loading capacity of ???? Amp. Find out the settings for O/C and E/F relay at End-A for time of operation as ???? msec. Bus-B 3-Ph short circuit current is ???? Amp and 1-Ph short circuit current is ???? Amp

Section-A: Calculations for Over-current Relay.

1) Overcurrent PSM (Roundup to 5%) =    %

2) For 3-ph fault CT secondary current =    Amp

3) For overcurrent relay CT secondary current as multiple of PSM =   X

4a) Time of operation for O/C relay with TMS 1 =   sec

4b) To have time of operation as ?? ms TMS =   %

Section-B: Calculations for Earth-fault Relay.

5) Earth fault PSM =   30%    20%    15%

6) For 1-ph fault CT secondary current =   Amp

7) For earthfault relay CT secondary current as multiple of PSM =   X.

8a) Time of operation for E/F relay with TMS 1 =   sec

8b) To have time of operation as ?? ms TMS =   %

Topic SETOCLN Ex-2 Your score is:

000

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ABD AMT NSK PUN NGP KRD VSH

ABD1 ABD2 JALN PRBN NND1 NND2 LTR1 LTR2 BEED PRLI EKTN GRWL WALJ TPTN KMBH