Lightning strike

By James Mulvey; posted June 19, 2009

View Original (783 x 482) 65KB

 


Unfortunately I removed the pin before I realized what I had. Units like this are installed where there is need of a temporary 'perch' for a hot clamp during installations or repairs on transformers The bracket clips to the crossarm, so that the rod is horizontal. The rod is copper and is grounded by copper wire. It is obvious that this unit took a strike and that the insulator had a crack at the time. The cast lead threads have melted and been forced out through the crack by the sudden pressure. A thin layer of lead can be seen that actually protrudes out past the side of the insulator.

When I was trying to fit the pin back into place I discovered why it had been hard to remove. The rest of the melted lead had been forced into any space between the existing remaining threads and the porcelain.

The porcelain immediately beneath the metal clamp has become discoloured by prolonged and repeated water penetration.

249993140