Example how to connect delta connected three-phaseCT set to the IED....................................................................50Example how to connect single-phase CT to the IED............ 53Relationships between setting parameter Base Current, CTrated primary current and minimum pickup of a protection IED.. 55Setting of voltage channels......................................................... 55Example................................................................................. 55Examples how to connect, configure and set VT inputsfor most commonly used VT connections.............................. 56Examples on how to connect a three phase-to-earthconnected VT to the IED........................................................ 57Example on how to connect a phase-to-phaseconnected VT to the IED........................................................ 59Example on how to connect an open delta VT to the IEDfor high impedance earthed or unearthed networks...............61Example how to connect the open delta VT to the IEDfor low impedance earthed or solidly earthedpower systems....................................................................... 64Section 5 Local HMI....................................................................... 67Display..............................................................................................68LEDs.................................................................................................70Keypad............................................................................................. 71Local HMI functionality..................................................................... 73Protection and alarm indication................................................... 73Parameter management .............................................................74Front communication................................................................... 75Section 6 Differential protection..................................................... 77Line differential protection................................................................ 77Identification................................................................................ 77Application................................................................................... 77Power transformers in the protected zone............................. 78Small power transformers in a tap..........................................79Charging current compensation............................................. 80Time synchronization............................................................. 82Communication channels for line differential protection.........82Configuration of analog signals.............................................. 84Configuration of output signals...............................................85Open CT detection................................................................. 85Setting guidelines........................................................................ 86General settings..................................................................... 86Percentage restrained differential operation.......................... 87The 2nd and 5th harmonic analysis....................................... 91Internal/external fault discriminator........................................ 92Table of contents2 Line differential protection RED650 2.2 IECApplication manual
