Motor protection

SIPROTEC 7SK85
The SIPROTEC 7SK85 motor protection device is designed for the protection of motors of all sizes.
Features & functions
With its modular structure, flexibility and the powerful DIGSI 5 engineering tool, SIPROTEC 7SK85 offers future-oriented solutions for protection, control, automation, monitoring and PQ basic. For motors in explosive environments, the SIPROTEC 7SK85 is also available with EN 60079-14 or Verband der Elektrotechnik, Elektronik und Informationstechnik 0165, Part 1 (ATEX) certification.Features
Main function:
- Motor protection for motors of all sizes
- Certification for use in explosive environments (EN 60079-14 or Verband der Elektrotechnik, Elektronik und Informationstechnik 0165, Part 1, ATEX)
Inputs and outputs:
3 predefined standard variants with
- 4 current transformers,
- 4 voltage transformers,
- 11 to 27 binary inputs,
- 9 to 17 binary outputs
Hardware flexibility:
- Flexibly adjustable and expandable I/O quantity structure within the scope of the modular SIPROTEC 5 system. 1/6 expansion modules can be added, available with large or small display, or without display
Width of housing:
- 1/3 × 19 inches to 2/1 × 19 inches
As standard:
Functions
DIGSI 5 permits all functions to be configured and combined as required.
- 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 (non-directional, 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 compensated or isolated electrical power systems using the following functions: 3I0>, V0>, transient ground fault, cos φ, sin φ, harmonic, dir. Detection of intermittent ground faults and admittance
- Ground fault detection using the pulse detection 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
PQ-Basic: voltage unbalance; voltage changes: overvoltage, dip, interruption; TDD, THD and Harmonics
- 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 61850-8-1, IEC 61850-9-2 Client, IEC 60870-5-103, IEC 60870-5-104, Modbus TCP, DNP3 serial and TCP, PROFINET IO, PROFINET IO S2 redundancy)
- Virtual
network sharing (IEEE 802.1Q - VLAN)
- Reliable data transmission via PRP and HSR redundancy protocols
- Extensive cybersecurity functionality, such as role-based access control (RBAC), protocolling security-related events, signed firmware or authenticated network access IEEE 802.1X
- Simple, quick and secure access to the device via a standard Web browser to display all information and diagnostic data, as well as vector diagrams, single-line and device display pages
- Secure serial protection data communication, also over great distances and all available physical media (optical fiber, two-wire connections and communication networks)
- Capturing operational measured variables and protection function measured values for the evaluation of the systems,to support commissioning, and to analyze faults
- Synchrophasor measured values with the IEEE C37.118 Phasor Measurement Unit (PMU)
- Powerful fault recording (buffer for a max. record time of 80 sec. at 8 kHz or 320 sec. at 2 kHz)
- Auxiliary functions for simple tests and commissioning
- Flexibly adjustable I/O quantity structure within the scope of the SIPROTEC 5 modular system
Applications
- Protection against thermal overload of the stator from overcurrent, cooling problems or pollution
- Protection against thermal overload of the rotor during startup due to: Frequent startups, excessively long startups or blocked rotor
- Monitoring for voltage unbalance or phase outage
- Monitoring the thermal state and the bearing temperatures with temperature measurement
- Detection of idling drives of pumps and compressors, for example
- Detection of ground faults in the motor
- Protection against motor short circuits
- Protection against instability due to undervoltage
- Acquisition
and recording of power quality data in the medium voltage and subordinate low
voltage network.
Benefits
- Safety due to powerful protection functions
- Purposeful and easy handling of devices and software thanks to a user-friendly design
- Cybersecurity in accordance with NERC CIP and BDEW Whitepaper requirements
- Highest availability even under extreme environmental conditions by “conformal coating“ of electronic boards
- Full compatibility between IEC 61850 Editions 1, 2.0 and 2.1