Effect of Barrier Angle on Tree Growth in Solid Insulation

In this research work the effect of barrier angle on tree resistance has been revealed in clear polyester resin. The work to be described studies the possible effect with angular displacement might have the progress of trees in the presence of barrier. The barriers were cast at 0 0 , 45 0 and 90 0 with respect to axis of symmetry of the field. The barrier selected for this study were glass and Melinex and PTFE castled in clear polyester resin C. The resin C was selected due to its transparent properties so optical observation and photographic record is possible. The selection of the materials was based on their work of adhesion. These materials were employed in a clear polyester resin thus making a barrier. The specimens, whatever the type (angle0 0 , 45 0 and 90 0 ) were tested in batches of 20 to establish their life time. This was measured in term of number of cycle to breakdown. Hypodermic needle was used as H.V electrode and 28kV A.C was the test voltage. The separation between electrodes is 2mm. The result shows that barriers offer higher resistance when disposed at 90 0 with respect to field. Effect of Barrier Angle on Tree Growth in Solid Insulation 25 3. Specimen manufacture: The specimens were made from resin containing 1% hardener by volume with a thin layer of particles lying between point and plane electrodes. Hypodermic needles were used as point electrode because they are sharp enough to support tree growth, cheap reproducible and readily available. The specimens were cast in strips in a silicone mould supported in a steel frame as shown in figure 2. The walls of the mould were lined on the inside with Melinex which ensured that the sides of the finished product had flat polished surfaces facilitating optical observation. Hypodermic needle electrode Spacer