LA Megger Test

[Humble2000]

Is meggering a lightning arrestor really a good test to show if the LA is good or not?
I usually test the 8KV and above Las at 5Kv and if I am reading more than 1000MG then I assume its good reading; however I am told that intermediate La’s are resetting themselves and meggering a LA is not a true test to show if they are good or bad!
I appreciate any comment on this subject

 

[pajce]

LA's for higher voltage levels are to be tested with DOBLE test (AC test up to 10 kV). For smaller voltage levels MV megger is practical test regarding time and material. Good arrestor reccomended value , look at NETA standars.
Hope this helps.

 

[Humble2000]

well, the question is if meggering an LA would show if the unit is good and I can put the power back on...
By the way, I checked hubble website and there is nothing mentioned about the megger test for LA

 

[DTR2011]

The megger test will probably not show anything significant (other than the obvious). Doble tests can be performed. An AC-Hypot is probably the most effective way to show that the device performs properly.

 

[JBinCA]

I've done a little research on the subject, and have found that field tests were'nt recommended by the manufacturers.

Doble tests would show you watt's loss (basically, how good of an insulator the LA is), and a HiPot can be used to find the strike voltage, but the manufacturers seem to say that the factory tests are hardly ever reproducable in field conditions.

My two cents.

JB