Overcurrent and Earth Fault Protection Relay
The 7SR210 series of relays provide overcurrent and earth fault protection. These relays are typically applied to provide the main protection on feeders and interconnectors and the back-up protection on items of plant such as transformers, Relays have four current inputs and are housed in E6 or E8 cases.
7SR220 series relays include for directional control of the overcurrent and earth fault functionality and are typically installed where fault current can flow in either direction i.e. on interconnected systems. Relays have five current and four voltage inputs they are housed in E6 or E8 cases.
Integrated logic is provided to allow the optimal configuration of relay functionality with the relays analogue inputs and binary input/output circuits. The optional auto-reclose feature offers an integrated solution for use on OHL feeders.
The relay functionality allows highly flexible settings for current and time grading making it compatible with all types of overcurrent protections.
Protection, instrumentation and metering functionality is accessible via data comms channel(s). A front USB port for local PC connection and rear electrical RS485 port for remote connection are provided as standard, additional ports are available as options.
Broken Conductor (46BC)
Negative Phase Sequence Overcurrent (46NPS)
Thermal Overload (49)
Overcurrent (50, 51)
Earth Fault (50G, 50N, 50SEF, 51G, 51N, 51SEF)
Directional Control of Overcurrent & Earth Fault (67)
High Impedance REF (64H)
Under/Over Voltage (27/59)
Negative Phase Sequence Voltage (47)
Voltage Controlled Overcurrent (51V)
Neutral Voltage Displacement (59N)
Under/Over Frequency (81)
CT Supervision (60CTS)
Trip & Close Circuit Supervision (74T/CCS)
VT Supervision (60VTS)
Inrush Detector (81HBL2)
Circuit Breaker Fail (50BF)
Auto Reclose (79)
Primary/Secondary Current Phases and Earth Direction
Primary/Secondary Line and Phase Voltages
Apparent Power and Power Factor
Real and Reactive Power
W Hr & VAr Hr Forward and Reverse
Historical Demand Record
Positive Phase Sequence (PPS) Voltage & Current
Negative Phase Sequence (NPS) Voltage & Current
Zero Phase Sequence (ZPS) Voltage
Cold Load Settings
Four Settings Groups
Password Protection - 2 levels
User Programmable Logic
Circuit Breaker Trip Counter and Timer
Fault, event and waveform records
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