AQ-F255B Line Differential Protection Device
AQ-F255_web
AQ-F255_web

Description

AQ-F255B offers a modular protection and control solution for line differential protection applications that require a large I/O capacity. Additionally, AQ-F255B integrates various current protection functions. However, if your application requires voltage protection and measurements, you can easily upgrade the B variant at any time to the AQ-F255C variant by updating the firmware.

Communication between the master node and the sub-node devices is performed over a smart process bus and it is easy to set. The process bus transfers both standard and user-defined data, and it automatically synchronizes the line differential protection settings from the master node device to the sub-node device. The process bus handles the compensation for delays in communication, which means that no external time synchronization is needed.

You can add up to eleven (11) I/O or communication modules into the device for extensive monitoring and control applications. AQ-F255B communicates using various communication protocols, including communication according to the IEC 61850 standard.

Line differential protection with a smart dedicated process bus.

Highlights:

  • A large I/O capacity.
  • Line differential protection for two line terminal ends.
  • Especially suitable for e.g. substations connecting wind and solar power facilities to the power grid.
  • Standard settings for communication – only the master node device needs to be selected.
  • Master node device synchronizes transfers, configurations, and settings to the sub-node device.
  • Transformer in the protected zone.
  • IEC 62443-4-2 compliant cybersecurity (security level 1).

See all AQ-F255 variants

AQ-F255_web

Technical data

  • Non-directional overcurrent (I>; 50/51) - 4 stages
  • Non-directional earth fault (I0>; 50N/51N) - 4 stages
  • Negative sequence overcurrent/ Phase current reversal/ Current unbalance (I2>; 46/46R/46L) - 4 stages
  • Harmonic overcurrent (Ih>; 50H/51H/68H) - 4 stages
  • Circuit breaker failure protection (CBFP; 50BF/52BF)
  • High-impedance or low-impedance restricted earth fault/ Cable end differential (I0d>; 87N)
  • Line thermal overload (TF>; 49F)
  • Line differential protection (IdL>; 87L)
  • Resistance temperature detectors (RTD)
  • Programmable stage (PSx>/<; 99)
  • Arc protection (IArc>/I0Arc>; 50Arc/50NArc) (optional)

  • Number of objects to control and monitor: 10
  • Number of indicators to monitor: 10
  • Number of setting groups: 8
  • Cold load pick-up (CLPU)
  • Switch-on-to-fault (SOTF)
  • Auto-recloser (0 → 1; 79)

  • Current transformer supervision
  • Circuit breaker wear monitoring
  • Total harmonic distortion (current)
  • Measurement recorder
  • Measurement value recorder
  • Event recorder (max. 15,000 permanent event records)
  • Disturbance recorder (max. 100 records á 5 seconds at 3.2 kHz sampling)

  • Phase, sequence and residual currents (IL1, IL2, IL3, I01, I02)
  • Frequency (f)

  • Standard hardware
  • Current inputs: 5
  • Digital inputs: 3
  • Digital outputs: 5
  • Number of empty slots: 11
  • Optional hardware modules
  • Digital input module (8 x DI)
  • Digital output module (5 x DO)
  • High-speed high-current output module (3 x out)
  • Milliampere input module (4 x mA in, 1 x mA out)
  • Milliampere output module (4 x mA out, 1 x mA in)
  • RTD input module (8 RTD inputs)
  • Arc protection module (4 x channels, 2 x HSO, 1 x BI)
  • Communication media (see "Communication" below)
  • External I/O modules (see "Accessories" below)

  • Standard communication ports
  • RJ-45 100 Mbps Ethernet (front panel)
  • RJ-45 100 Mbps Ethernet and RS-485 (rear panel)
  • Optional communication modules
  • Double RJ-45 Ethernet & IRIG-B communication module
  • Double ST Ethernet & IRIG-B communication module
  • Double SFP Ethernet & IRIG-B communication module
  • Double LC (HSR/PRP) Ethernet communication module
  • Double RJ-45 (HSR/PRP) Ethernet communication module
  • RS-232 & serial fiber communication module
  • Communication protocols
  • IEC 61850 (edition 1)
  • IEC 61850 (edition 2)
  • IEC 60870-5-101/104
  • IEC 60870-5-103
  • Modbus/RTU and Modbus/TCP
  • DNP3
  • SPA

  • AX007 External 6-channel 2-/3-wire RTD input module (pre-configured)
  • AX008 External 8-channel thermocouple and mA input module (pre-configured)
  • AX013 Raising frame (120 mm)
  • AX014 Raising frame (40 mm)
  • AX015 Wall mounting bracket
  • AX020 SFP module (2 km, MM)
  • AX021 SFP module (40 km, SM)
  • AX022 SFP module (120 km, SM)

Additional material

Application Drawing

AQ-F255B application drawings v1.03

Device Rear Image

AQ-255 back panel

Device and Cut-out Image

AQ 250 dimensions and cut out 2025

Order Code

F255

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