4160v distribution lines and lightning arrestors

[stardust]

Are lightning arrestors required on these lines (underground) or just recommended?

 

[junkhound]

location, location, location

here in PNW, PSE and Seattle city light use very few arrestors as we can go a few years without a good lightning storm, and even then they are only one or 2 stroke type piddly little thunder storms. Back in 1980, we had a once in 200 year (for here) Midwest/Florida type lightning storm and I heard from a city light employee that they lost 178 transformers that night.

 

[xformer]

location, location, location

here in PNW, PSE and Seattle city light use very few arrestors as we can go a few years without a good lightning storm, and even then they are only one or 2 stroke type piddly little thunder storms. Back in 1980, we had a once in 200 year (for here) Midwest/Florida type lightning storm and I heard from a city light employee that they lost 178 transformers that night.

That would keep a line crew busy for a bit...

 

[fmtjfw]

Do you need them? Depends on where you are.

Do you need them? Depends on where you are.

What does the local power company do? They have probably scoped this out.

cloud to ground state per year; sq mile
FL 1.3M; 24.1
LA 0.9M; 19.6
MS 0.9M; 18.2
AL 0.8M; 15.9
...
CA 0.08M; 0.5
OR 0.05M; 0.5
WA 0.02M; 0.3

complete list: http://www.lightningsafety.noaa.gov/stats/97-12Flash_DensitybyState.pdf