Siemens SIPROTEC 5 7SA82 Distance Protection Relay

The Siemens SIPROTEC 5 7SA82 is a compact and cost-optimized numerical relay designed for distance protection of transmission and distribution lines in medium- and high-voltage power systems. As part of the SIPROTEC 5 Compact series, it combines protection, control, monitoring, and automation functions into a single reliable device.

The relay provides advanced distance protection methods, including impedance-based and reactance-based algorithms, ensuring accurate fault detection even under complex network conditions. It also offers reliable ground fault detection and fast tripping, helping to minimize equipment damage and maintain system stability.

With seamless integration into digital substations, the 7SA82 supports IEC 61850 communication and is engineered using the powerful DIGSI 5 tool. Its compact design, conformal coating, and high availability make it ideal for both utility and industrial applications.

Main Function

• Distance protection for MV and HV lines
• Suitable for overhead lines and cable systems
• Backup protection for transformers, generators, motors, and busbars
• Supports radial, ring, and meshed network configurations

Tripping

• 3-pole tripping
• Minimum tripping time: ~19 ms

Inputs and Outputs

• 4 current transformer (CT) inputs
• 4 voltage transformer (VT) inputs
• 11 or 23 binary inputs
• 9 or 16 binary outputs

Hardware Flexibility

• Compact design with fixed I/O configuration
• Multiple predefined I/O quantity structures
• No expansion modules (cost-optimized design)
• Configurable using the DIGSI 5 engineering tool

Housing

• Compact 1/3 × 19-inch housing
• Available with a small or large display
• Standard conformal coating for harsh environments

Function (Key Features)

• Multiple distance protection methods:
  • Impedance-based protection
  • Reactance method (RMD)
• Directional backup protection
• Advanced ground fault detection:
  • Transient, intermittent, and harmonic-based methods
• Fault Locator Plus for accurate fault location
• Automatic reclosing (AREC) support
• Phasor Measurement Unit (PMU) functionality
• Basic power quality monitoring
• Fault recording and disturbance analysis
• IEC 61850 communication with digital substation integration
• Cybersecurity features and secure access via web interface