7/27/2019 Check List for Pt Injection

1/3

Maharashtra State Electricity Transmission Company

Testing & Communication Circle, Aurangabad

Check List for PT Injection Where ever No or Not Applicable (NA) selected, mention specific remarks on separate sheet Page 1 of3

CHECK LIST FOR PT INJECTION

EHV Sub Stn - Line / Bus - Date -

Make - Sr. No. - R ph Y ph B ph

PT HSV - Ratio -

Sr. No. Particulars of the test Whether carried out

1 Check and confirm tightness of all connections in PT MB

2 Check and confirm star point formation and earthing of star point of each core

3 Check and confirm correct formation of open delta in PT MB

4 Check and confirm earthing of one terminal of open delta

5 Check and confirm PT bus wiring in each CP / RP

6Check and confirm operation of PT selection scheme, if provided, before PTinjection

7 Check and confirm tightness of links of TBs / TTBs in all CP / RP

8Check and confirm proper gradation of HRC fuses in PT terminal box / PT MB andrespective CP / RP (6A HRC fuse in PT Terminal box, 4A HRC fuse in PTMB and 2A HRC fusein CP / RP)

9

Check and confirm magnitude and phase angle of voltages in respective protectiverelays / meters as per set value by carrying secondary PT injection through relevanttest kit in each core from PT MB(Carry out this test for confirmation of wiring)

10Check and confirm Ph to Ph and Ph to E voltages in all relays / meters as persettings during secondary PT injection

11Check and confirm operation of PT voltage selection scheme and measurevoltages accordingly as per the schematic during secondary PT injection

7/27/2019 Check List for Pt Injection

2/3

Maharashtra State Electricity Transmission Company

Testing & Communication Circle, Aurangabad

Check List for PT Injection Where ever No or Not Applicable (NA) selected, mention specific remarks on separate sheet Page 2 of3

12Remove PT secondary fuse in PT MB and check Open delta / zero sequencevoltage in Backup relay during secondary PT injection (Confirm this test for each phase)

13Apply 3ph 440V AC supply to PT primary and check PT secondary voltages atrespective protection relays / metering in each CP / RP

14 Check and confirm appropriate secondary voltage in all protective relays andmetering

15Remove one phase and check open delta / zero sequence voltage in Backuprelay(Confirm this test for each phase)

16 Check and confirm all PT fuses / MCBs in PT terminal box / PT MB / RP - CP

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Dy. Ex. Engineer

EHV Testing Unit

Project Testing Division -

LATUR

7/27/2019 Check List for Pt Injection

3/3

Maharashtra State Electricity Transmission Company

Testing & Communication Circle, Aurangabad

Check List for PT Injection Where ever No or Not Applicable (NA) selected, mention specific remarks on separate sheet Page 3 of3

Remarks about check point where No or NA selected

SrNo Short Description of Check Point Remarks

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