CMD – Multifunction Transducers

The CMD product line – Multifunction Transducers – are based on the SIGMA-N digital protection relay technology. They measure the electrical parameters of a High Voltage or Medium Voltage systems to produce analogue impressed current signals.

CMD6N – Multifunction Transducers Unit

The CMD6N Multifunction Transducers Unit is based on the SIGMA-N digital protection relay technology.

It performs the function of measurement transducer for electrical parameters in a HV or MV three-phase power

systems (balanced or unbalanced).

The following parameters are measured :

  • currents I1, I2 , I3
  • voltages U1, U2, U3
  • voltages U12 , U23 , U31
  • frequency
  • active power
  • reactive power
  • apparent power
  • power factor cos ϕ

All the measured electrical parameters are made available to SCADA system RTU’s through :

  • n°7 independently programmable impressed DC output currents
  • serial line RS485 – MOD BUS

The accuracy class of the measuring system is the following:

  • currents, voltages 0.2 %
  • powers 0.5 %
  • frequency 25 mHz
  • cosϕ 0.5 %

The response time 0-99% is ≤ 120 ms.

For the power measurement the following insertions of the CMD6N unit can be selected (programmed) :

  • Four-wire
  • Aron – three-wire
  • Single-phase (I1 – U1 )

Application – the CMD6N unit is designed to convert the electrical parameters of a three-phase power system for:

  • SCADA acquisition systems
  • Cogeneration control systems
  • Energy management systems
7 independently programmable impressed current outputs

Response time

120 ms

Currents      II, 12 , 13 CI 0.2
Voltages U1, U2, U3 CI 0.2
Voltages U12, U23 , U31 CI 0.2
Active power P CI 0.5
Reactive power Q CI 0.5
Apparent power A CI 0.5
Frequency 25 mHz
Keyboard on front panel RS232 interface
RS485 interface
4 output relay for alarm signalling