How i can do Stability testing for restricted earth fault?

We can perform stability test on restricted earth fault by following these steps :-

1 - choose one phase of primary windings like phase R and make short circuit connection between phase R before CT ,and N after CT .

2 - Prepare primary injection current equipment and connect it's first cable on phase R after CT , and its second cable at any earthed conductor near Neutral .

3 - start injection current up to 100 AMP , if the relay isn't trip , this mean the system is stable ,Also if the relay operate which mean there is a fault in connections which must be modified .

with best wishes ... Eng Ahmed Abdel men3m .