Question

In the overhead line insulator string for improving the string efficiency

(i) Long cross arms are used.

(ii) In the capacitance grading method, to improve the string efficiency, unit near the cross arm should have maximum capacitance and the unit near the conductor should have minimum capacitance.

(iii) Guard ring is used.

Which of the above is/are correct?

• A. i, ii
• B. i, ii, iii
• C. i, iii
• D. ii

Answer 1

The correct option is C i, iii

In the capacitance grading method, to improve the string efficiency the unit nearest the cross arm should have the minimum capacitance and as we go towards the power conductor the capacitance should increase.