How does the RCMI converter work?

The integration function of the RCMI converter is essential to balance the output signal of the Rogowski coils and shift it by 90°. The integrator consists of an active electronic circuit with negligible offset and good linearity. The output voltage signal from the Rogowski coil is converted into a standard 1 A signal.

The output voltage signal from the passive Rogowski coil is proportional to the frequency of the measured current. The equalizer installed ensures a linear signal to the primary current over a wide frequency range.

When ordering in conjunction with the RCM Rogowski coil, the primary nominal current must be specified. This results in a fixed transformation ratio, similar to a standard transformer. For example, 1000/1 A: The main measurement range of 0 to 1000 A is mapped to the secondary measurement range of 0 to 1 A.

Typical applications

  • Current measurement for automatic reactive power compensation batteries

  • Current measurement for active harmonic filters

  • Current measurement with existing meters and measurement units (input /5A or /1A)

  • Retrofit and measurement in existing installations

  • Metering and sub-metering, energy management systems

Advantages of the RCMI converter:

  • The RCMI converter does not measure direct currents when used with RCM Rogowski coils. Indeed, unlike a standard current transformer (CT), it can accurately measure the alternating current component even if a large superimposed direct current component is present, as there is no iron core to cause saturation. This function is particularly important for measuring ripple currents, for example, in battery charging systems.

  • The RCMI converter has relatively good frequency response characteristics.

  • Compact housing for connecting one RCM coil (RCMI-01) or three RCM coils (RCMI-03).

Dimensions

Technical characteristics

RCMI-01 RCMI-03
Number of phases 1 3
Nominal output current 1A AC rms
Max output current (overload) 1,5A AC rms
Nominal primary currents (A) 100, 250, 400, 600, 1000, 1500, 3000, 6000
Transmission accuracy 0.5% (at 1% of the nominal primary current @25°C)
Phase Error <= 0.5°
Linearity +/- 0.2% of measured value (at 10 to 120% of nominal current)
Bandwidth 30 Hz to 5 kHz
Max load per phase 0.5 Ohm
Power consumption 10 W
Output at 0 A (no drift) <= 0.01 A
Temperature drift 200 ppm/K
Weight 185 g
Dimensions 114 x 100 x 22.5 mm
Supply voltage 12V DC
Operating temperature range -30°C to +70°C
Storage temperature range -30°C to +70°C
Relative humidity Maximum 80% non-condensing
Protection IP 20
Certification CE – Cmim

Technical characteristics

The output signal (1A) must be exclusively connected to 1A or 5A current transformer inputs that are electrically isolated.

Connecting the input or output signal to an external voltage is prohibited. Doing so may result in the destruction of the RCMI converter.

Installation and Connection

Code Designation Nominal current Rogowski coil compatible
RCMI-03-0600M 1A measurement converter
for 3 Rogowski Coils R-36		 600A RCM-36
RCMI-03-1000M 1A measurement converter
for 3 Rogowski Coils R-100		 1000A RCM-100
RCMI-03-3000M 1A measurement converter
for 3 Rogowski Coils R-150		 3000A RCM-150
RCMI-03-6000M 1A measurement converter
for 3 Rogowski Coils R-200		 6000A RCM-200
RCMI-03-1000S 1A measurement converter
for 3 Rogowski Coils with 100mV/kA output		 1000A 3ème partie -100mV / 1kA
RCMI-01-0600M 1A measurement converter
for 1 Rogowski Coil RCM-36		 600A RCM-36
RCMI-01-1000M 1A measurement converter
for 1 Rogowski Coil RCM-100		 1000A RCM-100
RCMI-01-3000M 1A measurement converter
for 1 Rogowski Coil RCM-150		 3000A RCM-150
RCMI-01-6000M 1A measurement converter
for 1 Rogowski Coil RCM-200		 6000A RCM-200
RCMI-01-1000S 1A measurement converter
for 1 Rogowski Coil with 100mV/kA output		 1000A 3ème partie -100mV / 1kA

Other sizes and dimensions of Rogowski coils available upon request.