SIEMENS 7SJ8011-5EB90-1FA0/DD Protection Relay

Siemens 7SJ8011-5EB90-1FA0/DD Protection Relay

 

 

The Siemens 7SJ8011-5EB90-1FA0/DD is a SIPROTEC series digital protection relay, mainly used for overcurrent and earth fault protection in medium-voltage power systems. It belongs to Siemens’ 7SJ80 family, designed for feeder protection, motor protection, and general power system protection in industrial and utility networks.

This relay provides fast fault detection and tripping functions to protect electrical equipment such as cables, transformers, and distribution feeders.

Key Specifications

• Model: 7SJ8011-5EB90-1FA0/DD
• Series: Siemens SIPROTEC 7SJ80
• Product Type: Digital Protection Relay
• Protection Functions:
  • Overcurrent protection (ANSI 50/51)
  • Earth fault protection (50N/51N)
  • Thermal overload protection (49)
  • Undercurrent / unbalance protection (depending configuration)
• Current Inputs: 1A / 5A CT selectable
• Auxiliary Supply: 60–250 V DC / 115 V AC / 230 V AC
• Communication: RS485 / Modbus / optional PROFIBUS (variant dependent)
• Inputs/Outputs:
  • Digital inputs (BI) for status signals
  • Binary outputs (BO) for trip/alarm
• Mounting: Flush-mounted panel / 1/6 19” enclosure
• Interface: Front display + keypad for local operation
• Event Recording: Fault recording and diagnostics supported

Features & Advantages

• High-reliability digital protection for medium-voltage systems
• Fast and selective tripping for fault isolation
• Flexible configuration of protection functions and logic
• Built-in event recording and fault analysis
• Supports multiple communication protocols (variant dependent)
• Suitable for both industrial plants and utility substations
• Compact SIPROTEC modular design

Applications

• Medium-voltage feeder protection
• Industrial power distribution systems
• Transformers and motor protection
• Utility substations
• Oil & gas electrical networks
• Mining and heavy industry power systems

Precautions

• Requires correct CT/PT configuration before commissioning
• Incorrect settings can cause nuisance tripping or failure to trip
• Must be configured by qualified protection engineers
• Ensure correct auxiliary supply voltage (AC/DC range selection)
• Regular testing and maintenance required for safety compliance
• Firmware/settings backup recommended before replacement