Why CT body is connected with a wire to main bus bar?

A CT (current transformer) body is connected with a wire to the main bus bar to ensure accurate measurement of the electrical current flowing through the bus. This connection allows the CT to sense the magnetic field generated by the current in the bus bar, enabling it to convert the high primary current to a lower, manageable secondary current for measurement and monitoring purposes. Additionally, this setup helps protect equipment and enhances safety by isolating measurement devices from high voltage levels.