AQ-S391 Bay control IED

The AQ S391 bay control IED is suitable to various types of control and monitoring applications in extrahigh voltage, high voltage and medium voltage applications. The modular hardware construction offers required options for different kind of bay configurations in terms of type and quantity of analogue and digital signals. The versatile programmable software logic allows for extensive customization of provided standard configurations.



  • Control and monitoring of full diameter of single, double or one and half circuit breaker busbar configurations
  • Local and remote control and/or status indication of up to 12 controllable objects

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  • Circuit breaker control
  • Disconnector control
  • Synchrocheck (25)
  • Dead line detection function
  • Voltage transformer supervision function (60)
  • CT supervision
  • Trip circuit supervision (option)
  • Current (I1, I2, I3, Io)
  • Voltage (U1, U2, U3, U12, U23, U31, Uo) and frequency
  • Event recording
  • Non-volatile disturbance records: 100
  • Non-volatile event records: 10000
  • Current inputs: Max 8
  • Voltage inputs: Max 52
  • Digital inputs: Max 156
  • Digital outputs: Max 104
  • Fast trip outputs: 52
  • Analog input: MAX 52
  • RJ 45 Ethernet 100Mb (front standard)
  • RJ 45 Ethernet 100Mb (rear standard)
  • RS422/RS485/RS232 interfaces (option)
  • Plastic or glass fiber interfaces (option)
  • Communication protocols
  • IEC 61850
  • IEC 608705101,103,104
  • Modbus RTU and Modbus TCP/IP
  • DNP 3.0 and DNP 3.0 over TCP/IP
  • SPAbus