PORCELAIN END STRAIN INSULATOR THUNDERBIRD EF-25

The Thunderbird EF-25 is a porcelain bullnose end-strain insulator for terminating an electrified wire at an end, corner or strainer post on a permanent fence. It is not screwed into the post and there is no slot to thread — instead the strained fence wire loops through the porcelain and is wrapped back on itself, while the insulator is held to the post by a separate loop of plain (non-electrified) tie wire passed through the insulator and around the post. This keeps the live wire tensioned and clear of the post so power can't leak to earth. Tips: Use the long porcelain tracking path to your advantage — keep the insulator clean of dirt and bird droppings, which create leakage paths that drain fence voltage. Inspect for cracks or chips after storms, as even a small fracture lets energy leak away. Porcelain is fire-resistant and holds up well in the sun, but still check the tension and condition each season. Never test the fence by hand — use a fence voltage tester or fault finder.