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Product Code : 7SK85
Brand Name : Siemens
Product Description

SIEMENS SIPROTEC 7SK85 Motor protection relay


The motor protection device SIPROTEC 7SK85 is part of theSIPROTEC 5 series of modular field devices. This device is designed for theprotection of all motor sizes. With its flexibility and its high-performanceDIGSI 5 engineering tool, the SIPROTEC 7SK85 fits perfectly for protection,control, monitoring, and measuring applications in electrical energy systems. Mainfunction: Motor protection for all motor sizesTripping:3-poleInputs andoutputs:-3 predefined standard variants with 4 current-transformers, 4 voltagetransformers,-11 to 27 binary inputs, 9 to 17 binary outputs Hardwareflexibility: Flexibly adaptable and expandable I/O quantity structure withinthe scope of the modular SIPROTEC 5 building block, 1/6 expansion modules canbe added. Available with large or small display or without display Width ofhousing:1/3 x 19'' to 2/1 x 19''

All functions can be configured freely with DIGSI 5. For theapplication of some of the functions, you require the appropriate number offree function points within the device. The function point calculator in theonline configurator provides support in determining the required number offunction points for your device.


  • Motor protection functions: Startup time monitoring, thermal overload protection for stator and rotor, restart inhibit, unbalanced-load protection, load-jam protection
  • Stator and bearing temperature monitoring via temperature sensors with external RTD unit
  • Differential motor protection as fast short-circuit protection for motors of high power
  • Sensitive ground-fault protection (directional, non-directional) to detect stator ground faults
  • Directional and non-directional overcurrent protection (short-circuit protection) with additional functions
  • Detection of ground faults of any type in isolated or arc-suppression-coil-ground power systems using the following functions: 3I0>, V0>, fleeting contact, Cos-/SinPhi, harmonic, dir. detection of intermittent ground faults and admittance
  • Ground fault detection using the pulse location method
  • Overvoltage and undervoltage protection
  • Arc protection
  • Power protection, configurable as active or reactive power protection
  • Detection of current and voltage signals up to the 50th harmonic with high accuracy for selected protection functions (such as thermal overload protection) and operational measured values
  • Control, synchrocheck and switchgear interlocking protection
  • Graphical logic editor to create powerful automation functions in the device
  • Integrated electrical Ethernet RJ45 for DIGSI 5 and IEC 61850 (reporting and GOOSE)
  • Up to 4 pluggable communication modules, usable for different and redundant protocols (IEC 61850, IEC 60870-5-103, IEC 60870-5-104, DNP3 serial and TCP, Modbus TCP, PROFINET IO)
  • Redundancy protocols PRP and HSR
  • Cyber security to NERC CIP and BDWE Whitepaper requirements
  • Secure serial protection data communication, even over great distances and all available physical media (optical fiber cable, 2-wire connections and communication Networks)
  • Capturing operational measured variables and protection function measured values to evaluate the plant state, to support commissioning, and to analyze faults
  • Phasor Measurement Unit (PMU) for synchrophasor-measured values and IEEE C37.118 protocol
  • Powerful fault recording (buffer for a max. record time of 80 sec. at 8 kHz or 320 sec. at 2 kHz)
  • Auxiliary functions for easy tests and commissioning
  • Flexibly adjustable I/O quantity structure within the scope of the SIPROTEC 5 modular system



Office No.-9, Plot 53/54, Sector-34, Space Heights, Near Tawa Hotel, Kamothe, Navi Mumbai - 410209, Maharashtra, India
Mr Piyush Lalchand Rathi (Partner)
Mobile :+919819614841, +919769207841
Mr. Dnyanesh Gawande (Partner)
Mobile :+919833686249