The SIPROTEC ® 7SA6 distance protection relay is a universal protection control and automation on the basis of the SIPROTEC level of flexibility means it can be implemented at all voltage you are ideally equipped for the future: it offers security of saves on operating costs.
This is facilitated by the following features:

• Tested protection modules assure maximum safety
  
• Uniform operator software (DIGSI 4) for all SIPROTEC training costs
  
• Clearly laid out measured-value display saves on external instruments
  
• DIGSI 4 start-up aids speed up commissioning
  
• Integrated control unit saves space and money
  
• Flexible communication modules permit the use of protocol standards and give you security of investment
  
• Service interface for telecommunication reduces maintenance operating costs
  

The 7SA522 relay provides full scheme distance protection and incorporates all functions usually required for the protection of a power line. The relay is designed to provide fast and selective fault clearance on transmission and subtransmission overhead lines and cables. The power system star point can be solid or resistance grounded (earthed). The 7SA522 is suitable for single- and three-phase tripping applications with and without pilot (teleprotection) schemes. The 7SA522 incorporates several protective functions usually required for transmission line protection. These are

• Fault locator
  
• Power swing detection
  
• High resistance earth fault protection
  
• Phase overcurrent protection
  
• STUB bus overcurrent stage
  
• Overvoltage protection
  
• Automatic reclosure (available approx. October/99)
  
• Synchrocheck (available approx. October/99)
  
• Circuit breaker failure protection (available approx. October/99)
  
• Large scope of measured values
  

The integrated logic functionality (CFC according to IEC1131) allows the user to implement his own functions via a graphic user interface and to generate user-defined messages. Upgradeable communication modules are available for the entire SIPROTEC 4 range. In this way it is always possible to comply with the requirements of different communication protocols (DIGSI 4, IEC60870-5-103, Profibus-FMS.). All SIPROTEC 4 units can be operated easily via modem and/or star coupler, telecontrol and substation automation. DNP3.0, Profibus DP and Modbus RTU protocols will follow.

The 7SA510 distance protection relay provides fast, reliable and selective clearance of faults on overhead lines and cables, being fed from one or multiple points. The network can be radial, ring or meshed. The system start point may be isolated, resonance earthed (e.g. Peterson coil), solidly earthed or low-resistance earthed. The relay incorporates all functions normally required for line protection and can also be applied as a time-graded back-up protection for all types of differential protection schemes. The 7SA510 can be incorporated in both conventional switchgear systems and SINAUT LSA substation control and protection systems. The serial system interface protocol used conforms to IEC870-5-103 and can be connected to the fault monitoring computer DAKON or a starcoupler/modem central or remote operation system.

Note : Successive product = 7SA610.

The 7SA511 distance protection relay provides fast, reliable and selective clearance of faults on overhead lines and cables, being fed from one or multiple points. The network can be radial, ring or meshed. The system start point may be isolated, resonance earthed (e.g. Peterson coil), solidly earthed or low-resistance earthed. The relay incorporates all functions normally required for line protection and can also be applied as a time-graded back-up protection for all types of differential protection schemes. The 7SA511 can be incorporated in both conventional switchgear systems and SINAUT LSA substation control and protection systems. The serial system interface protocol used conforms to IEC870-5-103 and can be connected to the fault monitoring computer DAKON or a starcoupler/modem central or remote operation system.

Note : Successive product = 7SA611.

The 7SA518/519 numerical contact-line protection relay for railway catenaries provides selective and fast clearance of faults on overhead lines fed from one or multiple points in a 50/60 Hz radial, ring or meshed overhead line network. The relay possesses all functions required for line protection. Faults in the immediate vicinity of the relay location cause very high short-circuit currents to occur which must be cleared non-directionally within the shortest possible time. In order to ensure optimal loading also for sections which can be overloaded by high operating currents, the 7SA518/519 monitors the thermal loading of the catenary by means of a thermal protection device. The 7SA518 can be incorporated both in conventional switchgear systems and in modern substation control and protection systems.