Completely Self-Protected (CSP) Transformer Evaluation
Distribution transformers are one of the most important purchases utility makes. Investment in transformers constitutes a large percentage of the distribution plant investment each year. The types of transformers used and protection systems they employ also have a significant impact on continuity of and safety. Types of distribution transformers range from conventional transformers to Completely Self-Protected (CSP) units that incorporate overvoltage protection, internal primary fusing and secondary breakers. Selection of appropriate transformer types can have significant long term economic and reliability benefits for distribution systems. The purpose of this paper is to present the purchase options for overhead transformers, and to provide information on the relative merits of each option.