This part of JB/T 8510 applies to newly manufactured current transformers for measurement and protection of single-phase AC electrified railway traction power supply with a rated voltage of 27.5kV and a rated frequency of 5OHz. This part specifies the use conditions, ratings, design requirements, test classifications, test methods, markings, packaging, storage and transportation and random documents of current transformers for AC electrified railway traction power supply.