Siemens SIPROTEC 5 7SJ82 Feeder & Overcurrent Protection Relay

The Siemens SIPROTEC 5 7SJ82 is a compact and cost-optimized numerical relay designed for reliable feeder and overcurrent protection in medium- and high-voltage power systems. It is part of the SIPROTEC 5 Compact series, offering advanced protection, control, automation, and monitoring functions in a space-efficient design.

The relay is specifically engineered to provide cost-effective protection for feeders, lines, and capacitor banks, ensuring safe and stable operation of electrical networks. With powerful protection algorithms and support for DIGSI 5 engineering, it enables flexible configuration and seamless integration into modern substations.

The 7SJ82 supports directional and non-directional protection, advanced ground fault detection, and optimized tripping times, making it suitable for a wide range of applications, including radial, ring, and meshed networks.

Main Function

• Feeder and overcurrent protection for all voltage levels
• Suitable for feeders, lines, and capacitor banks
• Backup protection for transformers, generators, motors, and busbars

Tripping

• Selective 3-pole tripping for fast fault isolation
• Optimized tripping times using directional comparison and communication

Inputs and Outputs

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

Alternative configuration:

• 8 CT inputs
• 7 binary inputs
• 7 binary outputs

Hardware Flexibility

• Compact hardware with predefined I/O configurations
• Multiple hardware quantity structures available
• 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
• Conformal coating for harsh environmental conditions

Function (Key Features)

• Directional and non-directional overcurrent protection
• Advanced ground fault detection:
  • Transient, harmonic, and pulse-based methods
• Arc protection capability
• Overvoltage and undervoltage protection
• Frequency and load shedding protection
• Reverse power and reactive power protection
• Capacitor bank protection functions
• Fault recording and disturbance analysis
• Basic power quality monitoring
• IEC 61850 communication (Ed1 & Ed2 compatible)
• Redundancy protocols (PRP/HSR)
• Cybersecurity compliance (NERC CIP / BDEW)
• Time synchronization (IEEE 1588)