TLF/DAT Overcurrent Tests - Secondary Current Injection

Follow the below steps to perform the TLF/DAT overcurrent test - secondary current injection:

1. Select the required CT ration using 12 pin connectors on the PCBA board.

2. Replace both the fuses with temporary shorting links on PCBA board.

3. Connect the secondary injection test equipment as shown in below Figure – Schematic diagram of TLF/DAT Overcurrent Tests - Secondary Current Injection.

4. Close the disconnector and circuit breaker (respective ring switch mechanism) to Main ON.

5. Inject the CT secondary current 5 A in each phase in turn using the CT terminal block available in LV panel.

6. Remove the temporary shorting links and check whether the breaker trips, refer to the below Table – Phase Under Test.

7. Repeat steps 1 to 6 for remaining parts of phases (and CT ratio if required).