SIPROTEC 4 7SJ61
Multifunction protection relay
Description
The SIPROTEC 4 7SJ61 relays can be used for line protection of high and medium voltage networks with earthed (grounded), low-resistance earthed, isolated or compensated neutral point. When protecting motors, the SIPROTEC 4 7SJ61 is suitable for asynchronous machines of all sizes. The relay performs all functions of backup protection supplementary to transformer differential protection.
The relay provides a simple control of the circuit-breaker and automation functions. The integrated programmable logic (CFC) allows the user to implement their own functions, e. g. for the automation of switchgear (interlocking). The user is also allowed to generate user-defined messages.
The flexible communication interfaces are open for modern communication architectures with control systems.
Functions Overview
Protection functions
Time-overcurrent protection (definite-time/inverse-time/user-def.)
Sensitive earth-fault detection
Intermittent earth-fault protection
High-impedance restricted earth fault
Inrush restraint
Motor protection (Undercurrent monitoring, Starting time supervision, Restart inhibit, Locked rotor)
Overload protection
Temperature monitoring
Breaker failure protection
Negative-sequence protection
Auto-reclosure
Lockout
Control functions/programmable logic
Commands for control of a circuit-breaker and of isolators
Control via keyboard, binary inputs, DIGSI 4 or SCADA system
User-defined logic with CFC (e.g. interlocking)
Monitoring functions
Operational measured values
Circuit-breaker wear monitoring
Slave pointer
Time metering of operating hours
Trip circuit supervision
8 oscillographic fault records
Communication interfaces
System interface (IEC 60870-5-103, IEC 61850; PROFIBUS-FMS/-DP; DNP 3.0/MODBUS RTU)
Service interface for DIGSI 4 (modem) / Temperature detection (RTD-box)
Front interface for DIGSI 4
Time synchronisation via IRIG B/DCF77
Hardware
4 current transformers
3/8/11 binary inputs
4/8/6 output relays