Description The 7SR18 Solkor is a two ended line differential protection relay for overhead line and underground cable circuit applications as well as shorter circuits such as interconnectors. The relays primary differential protection function is supported by a comprehensive range of features to ensure a high level of stability with fast clearance of in zone faults. Main Function Line differential protection for distribution and industrial feeders upto 40km Inputs and Outputs 4 Current Transformers with 1A and 5A Inputs, 3 Voltage Transformers, 3 or 6 Binary Inputs and 5 or 8 Binary Outputs Communication Signalling channel - Fibre Optic 2km or 40km Data comms Front USB, Rear RS485, Rear option for Two Electrical or Two Optical Ethernet Housing Size E6, 4U high - withdrawable design Benefits • Compact cost effective solution • Signalling channel supervision • Multiple user selectable communication protocols • Local interface designed to ensure consistency across products and provide a user friendly access to the menu structure • Protection settings can be viewed and edited from the fascia • Optional Ethernet Optical or Electrical interface for IEC61850 compatible with IEC61850 Editions 1 & 2 • Redundancy protocols PRP and HSR supported. • User configurable alarms and indications provided on LCD and 9 coloured LEDS Applications • Line protection with phase segregated protection and indication • Two ended differential with 30ms operation for distribution networks • Integrated back up overcurrent • Integrated overcurrent guard function • Intertripping for both internal and external initiations

Protection functions • 87L 3-phase, phase segregated current differential protection • 50 Instantaneous Phase Overcurrent • 50G/N Instantaneous Earth fault • 51 Time Delayed Phase Overcurrent • 51G/N Time Delayed Earth fault • 46NPS Negative Phase Overcurrent • 49 Thermal Overload • 50 LC/540G LC Line Check (SOTF) • 67/50 Directional Instantaneous Overcurrent • 67/50G/N Directional Instantaneous Earth Fault • 67/51 Directional Time Delayed Overcurrent • 67/51G/N Directional Time Delayed Earth Fault Supervision Functions • Protection signalling communication supervision • 50BF Circuit breaker...