what is the spring's function in CT measure?

[vietto]

Hiall
When maintenance transmission system from generator to SF6 Breaker (20kv). i detected on transmission line from SF6 to Transformer have two spring which connect from CT to phase line (1 touch, 1 don't touch). Near location have electrical discharge from phase line (phase line coated by insulation paint) to spring (don't touch) to. I don't know spring's function in CT measure. I have picture show it. Many thanks

 

[Mbrooke]

Springs to my knowledge have no function in measuring. With that said they shouldn't be touching the cable either. Now, as to what and how they got there, I am just as puzzled as you.

 

[jghrist]

I guess that the spring is there to equalize the voltage and prevent arcing and radio interference if you had a bare conductor going through the CT window. What I have seen is a pigtail soldered to metalizing on the inside of the porcelain tube that is connected to bare conductors.

 

[JensenDrive]

Release of static charge on surface.