Acceptable Voltage Surge? 1

[tgott]

When closing in a 69 kV capacitor bank at a transmission substation (161/69 kV), what is a maximum acceptable voltage surge at the 69 kV bus? How about at the 69 kV buses one level away?

 

[dpc]

It would be preferable to keep it below the rating of your surge arresters.

For a **solidly-grounded** 69 kV system, the Maximum continuous operating voltage of the arrester should be at least 42 kV. With a 42 kV MCOV, the arrester voltage rating is 54 kV.

Per the data I have at hand, an ABB EXLIM-P arrester rated 54 kV has a switching surge rating 103 kV based on a time to crest of 45 to 60 microseconds.

Hope that helps.