7SJ62 Multifunction Over Current Protection Relay
The SIPROTEC 4 7SJ62 relays can be used for line protection of high and medium voltage networks with earthed (grounded), low-resistance earthed, isolated or compensated neutral point. With regard to motor protection, the SIPROTEC 4 7SJ62 is suitable for asynchronous machines of all sizes.The relay performs all functions of backup protection supplementary to transformer differential protection. 7SJ62 is featuring the "flexible protection functions". Up to 20 protection functions can be added according to individual requirements. Thus, for example, a rate-of-frequency-change protection or reverse power protection can be implemented.The relay provides 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.
Overcurrent protection (definite-time/inverse-time/user-def.)
Directional overcurrent protection (definite-time/inverse-time/user-def.)
Sensitive dir. earth-fault detection
Displacement voltage
Intermittent earth-fault protection
Directional intermittent ground fault protection
High-impedance restricted earth fault
Inrush restraint
Motor protection
Overload protection
Temperature monitoring
Under-/overvoltage protection
Under-/overfrequency protection
Rate-of-frequency-change protection
Power protection (e.g. reverse, factor)
Undervoltage controlled reactive power protection
Breaker failure protection
Negative-sequence protection
Phase-sequence monitoring
Synchro-check
Auto-reclosure
Fault locator
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 V,l,f
Energy metering values Wp,Wq
Circuit-breaker wear monitoring
Slave pointer
Trip circuit supervision
Fuse failure monitor
8 oscillographic fault records
Motor Statistics
COMMUNICATION INTERFACES
System interface
– IEC 60870-5-103/ IEC 61850
– PROFIBUS-FMS/-DP
– DNP 3.0/MODBUS RTU
Service interface for DIGSI 4 (modem)
Front interface for DIGSI 4
Time synchronization via IRIG B/DCF77
HARDWARE
4 current transformers
3/4 voltage transformers
8/11 binary inputs
8/6 output relays