AQ200 Series – AQ-T216 Transformer Protection Relay

The Arcteq AQ T216 is a transformer protection relay with sophisticated and easy to use differential protection function.


The AQ T216 transformer protection relay provides for both low and high side overcurrent, earth-fault, negative sequence and two independent restricted earth-fault instances.

The AQ T216 can be applied for generator and motor differential protection as well. The AQ T216 communicates using various protocols including IEC 61850 substation communication standard.


Key features of the AQ T216 Transformer Protection Relay

Protection functions

  • 2 winding transformer differential (87T)
  • High/low impedance restricted earth fault / cable end differential * (87N1, 87N2)
  • Transformer thermal overload (49T/49RTD)
  • Three-phase overcurrent, 2+2 stages INST, DT or IDMT (50/51)
  • Earth-fault (sensitive), 3 stages INST, DT or IDMT (50/51N)
  • Harmonic overcurrent / inrush blocking, 4 stages INST, DT or IDMT (50/51H, 68)
  • Current unbalance / broken conductor, 2+2 stages INST, DT or IDMT (46/46R/46L)
  • Breaker failure protection (50BF/52BF)
  • Arc protection (option) (50ARC/50NARC) (12 sensors +2xHSO +BI)

Measuring and monitoring

  • Phase and residual currents (IL1, IL2, IL3, I01, I02)
  • Current THD and harmonics (up to 31st)
  • Frequency (f)
  • Circuit breaker wear (CBW)
  • Disturbance recorder (3.2 kHz)
  • Current transformer supervision (CTS), 2 instances
  • Trip circuit supervision (TCS)


  • Current inputs: 5
  • Digital inputs: 3 (standard)
  • Output relays: 5+1 (standard)

Event recording

  • Non-volatile disturbance records: 100
  • Non-volatile event records: 15000

Communication media

  • RJ 45 Ethernet 100Mb (front standard)
  • RJ 45 Ethernet 100Mb and RS 485 (rear standard)
  • Double LC Ethernet 100Mb (option)
  • RS232 + serial fibre PP/PG/GP/GG (option)

Communication protocols standard

  • IEC 61850
  • IEC 60870-5-103/101/104
  • Modbus RTU, Modbus TCP/IP
  • DNP 3.0, DNP 3.0 over TCP/IP
  • SPA