This is a test equipment to test & measure Relative Resistance to Vented Water-Tree Growth in Solid Dielectric Insulating Materials.
This is a laboratory tester designed to simulate the growth of vented water-trees in the solid dielectric insulating material initiated by a sharp protrusion at the insulating and conductive interface under a wet environment in a high electrical field.
The system comprises, Power Source, Siemens make PLC and Water Bath.
As per ASTM D 6097 – 01a, Ten compression-molded disk specimens, each containing a conical-shaped defect, are subjected to an applied voltage of 5 kV at 1 kHz and 23 ± 2°C in an aqueous conductive solution of 1.0 N NaCl for 30 days. This controlled conical defect is created by a sharp needle with an included angle of 60° and a tip radius of 3 µm. W also have a variant to test at even higher frequencies
The electrical stress at the defect tip is enhanced and can be estimated by the Mason’s Hyperbolic point-to-plane stress enhancement equation. This enhanced electrical stress initiates the formation of a vented water-tree grown from the defect tip. Each tree specimen is stained and sliced
The water-tree length and point-to-plane specimen thickness measured under microscope are used to calculate a ratio that is defined as the resistance to water-tree growth