Power Transformer Data: Power Transformer Rating Rated Primary Current in 13.33 MVA Base Rated Secondary Current in 13.33 MVA Base Rated HV Voltage Rated LV Voltage Vector Group % Impedance
10/13.33 MVA 233.2 A 699.6 A 33 kV 11 kV Dyn11 11.33%
Physical Inspection: Visual Check for External Damage Condition of Front HMI Condition of Key Pad Condition of LED
Found OK Found OK Found OK Found OK
Measurement and Status Checks: Analog Input (CT Current) Checks Binary Input/Opto-Coupler Status Binary Output/Contact/Command Relay Front HMI LED
Found OK Found OK Found OK Found OK
LED Labels: LED Serial No 1 2 3 4 5 6 7
Signal Differential Trip HV Side Differential Trip LV Side External Trip External Trip General Over Current Trip Phase Over Current Trip 3I0 Trip (Residual O/C Trip)
Functions Configured in the Relay (Base on Function Availability): Serial No 1 2 3
Function Name Differential Function (87T) HV Phase O/C Function (51) HV Phase Residual O/C (51N)
Test of HV Differential Function: Phase R Y B
Set I/In 0.30 0.30 0.30
Operated at I 1.13 A 1.13 A 1.14 A
Delay 28 ms 28 ms 29 ms
Remark OK OK OK
Delay 29 ms 29 ms 29 ms
Remark OK OK OK
Test of LV Differential Function: Phase R Y B
Set I/In 0.30 0.30 0.30
Operated at I 0.63 A 0.64 A 0.63 A
Test of Phase O/C Function (DMT): Phase R Y B
Set I 4.0 A 4.0 A 4.0 A
Set t 500 ms 500 ms 500 ms
Operated at I 3.97 A 3.97 A 3.98 A
Delay 504 ms 503 ms 504 ms
Remark OK OK OK
Test of Residual O/C Function (DMT): Phase R Y B
Set I 1.5 A 1.5 A 1.5 A
Set t 400 ms 400 ms 400 ms
Operated at I 1.52 A 1.49 A 1.51 A
Delay 402 ms 403 ms 403 ms
Remark OK OK OK
Differential Stability Check: Found stable at load condition and external faults.
