Multifunction protection
SIPROTEC 7SJ61
The SIPROTEC 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 7SJ61 is suitable for asynchronous machines of all sizes. The relay performs all functions of backup protection supplementary to transformer differential protection.
Features
The relay provides control of the circuitbreaker, further switching devices 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.
Hardware
- 4 current transformers
- 3/8/11 binary inputs
- 4/8/6 output relays
- Text display or graphical display
- Surface-mounting or flush-mounting housing
Communication interfaces
System port
– IEC 61850
– PROFINET
– DNP3 TCP
– IEC 60870-5-103
– PROFIBUS-DP
– DNP 3.0– MODBUS RTU
Service port
– DIGSI 4,
– Modem
– Thermobox
Front port
– DIGSI 4
Time synchronization via IRIG B/DCF77
Functions
Protection functions
- Overcurrent protection (definite-time/inverse-time/user-def.)
- Sensitive earth-fault detection
- Intermittent earth-fault protection
- High-impedance restricted earth fault
- Inrush - Current detection
- Motor protection
– Undercurrent monitoring
– Starting time supervision
– Restart inhibit
– Locked rotor
– Load jam protection - 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
- Position of switching elements is shown on the graphic display
- 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
Motor statistics
