OPGW

[Blackberry77]

Hi,

If I have an overhead line with OPGW at the top and have it down pole grounded every number of poles are surge arresters required on the line?

 

[waross]

Always a good idea adjacent to transformers.

Bill
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"Why not the best?"
Jimmy Carter

 

[cuky2000]

The short answer is NO. A surge arrester is not necessarily needed in every pole.

Although it is recognized that installing a line surge arrester help to mitigate the line overvoltage due to a lightning strike, however installing surge arresters in every pole it could be an unusually expensive proposition.

Many overhead lines around the globe with good operation performance do not have any surge arrester at all. To determine if a line arrester is needed, it is recommended to perform an insulation coordination study and an economic analysis to find the risk/benefit if the number of failures is acceptable for the extra cost of the line.

Keep in mind that a line failure is a self-restoring failure that many utility addresses using a reclosing scheme in the line protection system.

See the sketch below to give a partial pictorial view of the issue but it is recommended to consider this in a case-by-case basis.