Motor and generator protection

SIPROTEC 7SK80 and SIPROTEC 7SK81

The SIPROTEC 7SK80 and SIPROTEC 7SK81 are a multi-functional motor protection relays.

They are designed for protection of asynchronous motors of all sizes.

SIPROTEC 7SK80 - Motor protection

4xI 0/3xV, small and medium-sized motors

The SIPROTEC 7SK80 is a multi-functional motor protection relay. It is designed for protection of asynchronous motors of all sizes. The relays have all the required functions to be applied as a backup relay to a transber differential relay.

Features

The SIPROTEC 7SK80 features “flexible protection functions”. Up to 20 additional protection functions can be created by the user.

Therefore protection of change for frequency or reverse power protection can be realized, for example.

The relay provides circuit-breaker control, further switching devices and automation functions. The integrated programmable logic (CFC) allows the user to add own functions, e.g. for the automation of switchgear (interlocking). The user is also allowed to generate user-defined messages.

Hardware

• 4 current transbers
• 0 / 3 voltage transbers
• 3 / 7 binary bs (thresholds configurable using software)
• 5 / 8 binary outputs (2 changeover)
• 0 / 5 RTD bs
• 1 life contact
• Pluggable current and voltage terminals.

Product homepage - downloads from the internet (catalogs, certificates, firmware, manuals,...)

www.siemens.com/7SK80

The SIPROTEC 7SK80 unit is a numerical motor protection relay that can perb control and monitoring functions and therefore provide the user with a cost-effective platb for power system management, that ensures reliable supply of electrical power to the customers. The ergonomic design makes control easy from the relay front panel. A large, easyto-read display was a key design factor.

Control

The integrated control function permits control of disconnect devices, grounding switches or circuit-breakers through the integrated operator panel, binary bs, DIGSI 4 or the control or automation system (e.g. SICAM).

Programmable logic

The integrated logic characteristics (CFC) allow the user to add own functions for automation of switchgear (e.g. interlocking) or switching sequence. The user can also generate user-defi ned messages. This functionality can b the base to create extremely flexible transfer schemes. Operational measured value Extensive measured values (e.g. I, V), metered values (e.g.Wp,Wq) and limit values (e.g. for voltage, frequency) provide improved system management.

Operational indication

Event logs, trip logs, fault records and statistics documents are stored in the relay to provide the user or operator with all the key data required to operate modern substations.

Motor protection

The SIPROTEC 7SK80 device is specifically designed to protect induction-type asynchronous motors.

Line protection

SIPROTEC 7SK80 units can be used for line protection of high and medium-voltage networks with grounded, low-resistance grounded, isolated or a compensated neutral point.

Transber protection

The SIPROTEC 7SK80 device provides all the functions for backup protection for transber differential protection. The inrush suppression effectively prevents unwanted trips that can be caused by inrush currents.

Backup protection

As a backup protection the SIPROTEC 7SK80 devices are universally applicable.

Switchgear cubicles for high / medium voltage

All units are designed specifically to meet the requirements of high / medium-voltage applications. In general, no separate measuring instruments (e.g., for current, voltage, frequency, …) or additional control components are necessary.

Protection functions

• overcurrent protection (50, 50N, 51, 51N, 51V)
• Directional overcurrent protection, ground (67N)
• Sensitive dir. ground-fault detection (64,67Ns/67N)
• Motor protection
  • Undercurrent monitoring (37)
  • Starting time supervision (48)
  • Restart inhibit (66/86)
  • Locked rotor (14)
  • Load jam protection (51M)
• Thermal Overload protection (49)
• Under-/overvoltage protection (27/59)
• frequency protection (81O/U)
• Breaker failure protection (50BF)
• unbalance-load protection (46)
• Lockout (86)

Control functions/programmable logic

• Commands for the ctrl. of CB, disconnect switches (isolators/isolating switches)
• Control through keyboard, binary bs, DIGSI 4 or SCADA system
• User-defined PLC logic with CFC (e.g. interl.)

Monitoring functions

• Operational measured values
• Energy metering values W p , W q
• Circuit-breaker wear monitoring
• Minimum and maximum values
• Trip circuit supervision
• Fuse failure monitor
• 8 oscillographic fault records
• Motor statistics

ATEX100-certification:

The Device is available with ATEX100-certifi cation for protection of explosion-proved machines of increasedsafety type ”e“

Communication interfaces

• System/service interface
  • IEC 61850 Edition 1 and 2
  • IEC 60870-5-103 and IEC 60870-5-104
  • PROFIBUS-DP
  • DNP 3.0
  • MODBUS RTU
  • DNP3 TCP
  • PROFINET
  • Ethernet redundancy protocols RSTP, PRP and HSR
• Ethernet interface for DIGSI 4, and extension from up to two SICAM I / O-Units 7XV5673 as well as a RTD box
• USB front interface for DIGSI 4

Hardware

• 4 current transbers
• 0/3 voltage transbers
• 3/7 binary bs (thresholds configurable using software)
• 5/8 binary outputs (2 changeover/Form C contacts)
• 0/5 RTD bs
• 1 live-status contact
• Pluggable current and voltage terminals