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Siemens Reyrolle 7SR57 Motor Protection Numerical Relay

Siemens Reyrolle 7SR57 Motor Protection Numerical Relay
Siemens Reyrolle 7SR57 Motor Protection Numerical Relay
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Product Code : 7SR57
Brand Name : Siemens
Product Description
Siemens Reyrolle 7SR57 Motor Protection Numerical Relay

Siemens Reyrolle 7SR57 motor protection relay includes a wide range of protection functions and IEC 61850 Ethernet communications as standard. To further minimize the product variants the power supply and the binary inputs cover the full operating range with configurable binary input thresholds.


The Reyrolle 5 is designed for the electricity networks of the future with enhanced communications and cyber security while maintaining a user-friendly interface and easy product management.

The 7SR57 motor protection devices include a wide range of protection functions and IEC 61850 Ethernet communications as standard. To further minimize the product variants the power supply and the binary inputs cover the full operating range with configurable binary input thresholds.

The large LCD, tactile push buttons and programmable LEDs provide a user-friendly product interface and the relay element is withdrawable for easy replacement.

Inputs and outputs

  • 4 CT + 8 BI + 6 BO
  • 4 CT + 13 BI + 8 BO
  • 4 CT + 4 VT + 9 BI + 8 BO
  • 4 CT + 4 VT + 19 BI + 12 BO


Standard front USB port (for configuration using Reydisp PC based software tool) rear RS485, 2 x RJ45 electrical ports or optional optical ethernet connections.

Size 6 or 12 with drawable design. Display Backlit 128 x 128 LCD with text and graphical display capabilities suitable for single line mimic diagrams.


Standard functionality

  • 14 Locked rotor protection
  • 37/37G Undercurrent protection  phase/earth
  • 46BC Broken conductor detection
  • 46PR Phase-rotation reversal
  • 46UB Phase unbalance
  • 48 Starting-time supervision
  • 49R Rotor thermal overload protection
  • 49TS Temperature sensor supervision 11
  • 50/ 50N/ 50G  Instantaneous overcurrent
  • 50AFD Arc flash detection
  • 50BCL Break capacity limit
  • 50BF Circuit-breaker failure protection - 3 pole
  • 51/ 51N/ 51G Time delayed overcurrent
  • 52 Circuit-breaker control
  • 60CTS CT supervision
  • 74TC/ 74CC Trip-circuit and close-circuit supervision
  • 79 Automatic reclosing
  • 81B Backspin monitor
  • 81HB2 Inrush current detection
  • 86 Lockout
  • 87GH Restricted earth fault protection high impedance

Optional functionality Siemens Reyrolle 7SR57

  • 27/27Vx Undervoltage protection
  • 32 Power protection
  • 47 Sequence overvoltage protection
  • 55 Power factor
  • 59/ 59Vx Overvoltage protection
  • 59N Neutral voltage displacement
  • 60VTS VT supervision
  • 67/ 67N/ 67G Directional overcurrent
  • 81 Frequency protection  "f>" or "f<"
  • 81R Frequency protection  "df/dt

Monitoring functions of Siemens 7SR57 numerical relay

  • Primary, secondary and phase sequence current & voltage
  • Frequency, power, and energy
  • Fault data, event and waveform records
  • Motor start data log


  • IEC 60870-5-103, MODBUS-RTU, DNP3, IEC 61850


  • Motor protection functions designed to protect during all motor starting and running sequences
  • Thermal algorithm optimized to closely match the thermal characteristics of motors
  • Thermal monitoring via plant temperature sensors supported

Benefits of Siemens 7SR57 numerical relay

  • Compact design and low product life-cycle cost
  • Reliable operation due to powerful, proven protection algorithms
  • IEC 61850 Edition 1 & 2 with HSR, PRP and RSTP operation for increased availability
  • Simple product ordering
  • Combined 1 A and 5 A current transformer inputs
  • 28 programmable tri-color LEDs for clear indications.
  • User selectable languages: English, French, German, Portugese, Spanish, Turkish

The protection, control, monitoring and measuring of our power networks is a vital element in managing our electrical assets, increasing reliability, sustainability and the safety of operating personnel. Our goal is to provide protection devices which provide flexible solutions and easy integration into an energy market which is becoming increasingly decentralized and digitalized. With the new Reyrolle 5  we have listened to the changing needs of our customers. With IEC 61850 Ethernet communications as standard and enhanced cyber security the Reyrolle 5 enables substation digitalization. The user friendly, intuitive design and minimal ordering variants gives confidence to the user and this extends to the Reydisp programming software tools.


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