AQ-S391 Bay control IED

The AQ-S391 bay control IED can be applied to various types of control and monitoring applications (extrahigh-voltage, high-voltage and medium-voltage applications). The modular hardware construction offers many options for different kinds of bay configurations: you can add up to nineteen (19) I/O cards, which allows for a variety of analog and digital signals both in type and quantity. The versatile and programmable software logic allows for extensive customization for the standard configurations provided with the unit.



  • Control and monitoring for a full diameter of single, double or one-and-a-half circuit breaker busbar configurations
  • Local and remote control
  • Status indication for of up to twelve (12) controllable objects.

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  • Circuit breaker failure protection (CBFP; 50BF/52BF)
  • Disconnector control
  • Dead line detection
  • Synchrocheck (ΔV/Δa/Δf; 25)
  • Number of supervised trip contacts: 4
  • Voltage transformer supervision (60)
  • Current transformer supervision
  • CPU module (MM/ST + RJ-45)
  • Power supply module (PS + fault relay + 2 trips)
  • Number of empty slots: 19
  • RJ-45 100 Mbps Ethernet + MM/ST fiber optic Ethernet
  • IEC 61850 (optional)
  • IEC 60870-5-101/104/103
  • Modbus/RTU and Modbus/TCP
  • DNP3.0

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