2c73-technical-bulletin.pdf
The 2C73 relay provides high-speed differential protection for power system plant including generators, busbars, motors and the individual windings of power transformers, and is also suitable for restricted earth fault protection. Under through-fault conditions, line current transformers can saturate and cause ratio errors, circuit imbalance and false tripping. To ensure stability, this high impedance differential relay operates at a voltage slightly higher than the worst-case through-fault condition, while still tripping reliably on internal faults. It is a single-phase device in a compact size 2M draw-out case; use three units for three-phase applications.
