Comparison of Top-Core and Hair-Pin Current Transformers – State of the Art

This article compares the construction, materials, and operational characteristics of two types of instrument transformers: Hair-pin Instrument Transformers (HPIT) and Top-core Instrument Transformers (TCIT). It highlights their key similarities and differences, especially in terms of insulation, primary conductor design, and installation. The discussion focuses on the advantages and disadvantages of each type, providing insight into their suitability for different power system applications. The analysis serves as a foundation for selecting the appropriate design based on operational needs and system requirements.