Manual for RET670 9-2 LE

The RET670 is a transformer protection IED designed for advanced applications. It features a fast differential protection function with settable CT ratio matching and vector group compensation, making it suitable for demanding scenarios without interposing CTs. The IED supports multi-breaker arrangements with up to six restraint CT inputs and includes 2nd and 5th harmonic restraint to prevent nuisance tripping. A sensitive differential protection element based on symmetrical components is also included for turn-to-turn fault coverage. The device offers restricted earth-fault protection, distance protection as backup, and versatile overcurrent functions. It also includes a disturbance and event recorder, breaker failure protection, and synchrocheck functionality. The RET670 can integrate with IEC 61850-9-2LE process bus and supports advanced logic capabilities for custom applications.