Kraft Paper Insulated Conductor for a Railway Transformer Project

In railway traction applications the transformer operates under continuously changing load and vibration. In this project, flat-surface, high-tensile kraft paper insulation was chosen for the main winding conductor; at the lead-outs where the conductor changes direction and the cross-section widens, crepe paper was used so the insulation follows without leaving voids.

Because of the hygroscopic nature of paper insulation, packaging criteria were written into the order text: moisture-barrier sealed packaging, desiccant and controlled post-delivery storage conditions were defined. Paper requirements were set with reference to IEC 60554; each batch was shipped with an EN 10204 3.1 certificate.

During winding production the overlap ratio and total insulation thickness were verified together with the customer quality team. Batch numbers were matched to the winding production records, providing full traceability throughout the project.