AQ-B398 Busbar protection IED

AQ-B398 busbar protection IED comes in two versions: one version is a centralized busbar protection unit (AQ-B398C), while the second is a main unit for distributed busbar protection applications (AQ-B329D). In distributed busbar protection applications the unit communicates with bay units using the IEC 61850-9 intercommunication standard. The bay unit can be any of the AQ-300 IEDs with the incorporated busbar protection bay unit functionality. AQ-B398 provides a total trip time of less than 20 ms for busbar faults.



  • Centralized busbar protection
    • A maximum of six (6) bays and two (2) busbar sections in a three-phase configuration
    • A maximum of  24 bays and eight (8) busbar sections in a single-phase configuration
  • Distributed busbar protection
    • A maximum of 24 bays
    • A synchronizing signal with 1 ms time intervals in a distributed configuration

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  • Circuit breaker failure protection (CBFP; 50BF/52BF)
  • AQ-2000Q
  • Distributed busbar protection (sub-unit) (optional)
  • Number of supervised trip contacts: 8
  • Current (IL1, IL2, IL3, I0)
  • Voltage (U1, U2, U3, U12, U23, U31, U0) and frequency
  • Power (P, Q, S, pf) and Energy (E+, E-, Eq+, Eq-)
  • Event recorder (max. 10 000 permanent event records)
  • Circuit breaker wear monitoring
  • Number of empty slots: 6
  • CPU module (MM/ST + RJ-45)
  • Power supply module (PS + fault relay)
  • Voltage measurement module
  • Current measurement module (3 instances)
  • 4-channel RTD module
  • 48 digital inputs (4 x 12 DI)
  • 16 digital inputs (2x8)
  • Options
  • One (1) additional voltage measurement module
  • One to three (1-3) additional voltage measurement modules
  • RJ-45 100 Mbps Ethernet + MM/ST fiber optic Ethernet
  • IEC 60870-5-101/104/103
  • Modbus/RTU and Modbus/TCP
  • DNP3.0
  • Options
  • 2 x ST/MM redundant fiber optic Ethernet
  • ST/MM fiber optic Ethernet and RS-485
  • Options
  • IEC 61850 Edition 1