Damage of a distribution transformer due to through-fault currents: an electrical forensics viewpoint

Insurance coverage for commercial premises includes direct loss and damage of the mechanical and electrical plant as well as consequential loss or damage. In recent years, many electrical failures have given rise to huge claims. It is therefore also in the interest of the electric power engineering community that the reliability of new systems being designed is acceptable and justified in the light of escalating claims for consequential loss or damage. For many existing power distribution systems in Singapore, it may require a reassessment of the need for additional features to improve the reliability. A case study is presented in this paper to illustrate this point. The case involved a failure investigation that was conducted on a distribution dry-type transformer.