Power Monitoring with RMS and ADC interface

Today I would like to show you a way to monitor the current and power consumption consumption with RMS using a RMS device with standard ADC interface (0-10V).


The AC current is measured using a contactless current transducer. This component detects the magnetic field around the AC cable and measures the AC current by this principle. Beyond this, the sensor uses the magnetic field also to power his own sensor electronic and the interface of the transducer. So it doesn't need a seperate power supply.
The standard interface (0-10V) is connected to a RMS device with ADC (Analogue-Digital-Convertion), e. g. a RMS-MADC-868-V (1 CH RF device) or a RMS-ADC-L-R (2 CH LAN device for DIN Rail) which transmit the information of the current consumption to the RMS.

The advantage is, that this setup can be installed into electrical cabinets, even into already installed or running systems. The current sensor can be clipped around the measured cable without opening the cable connection.


How to integrate the measurement into the RMS Software using a RMS-MADC-868-V

AC current

• Add a new device (Click on Tools -> Setup -> Devices -> New -> Wireless -> Select a gateway …)
• Set the input scaling – Measurement range low and high of the RMS-MADC-868-V.
  Now a look into the sensor datasheet is necessary. I used an AT 5 B5 sensor. For the current range of Ipn 0 … 5Amp AC, the sensor output voltage (interface signal) is 0 … 5VDC.
  For the input scaling of the RMS-MADC-868-V, the low and high range is to be set:
  • Measurement range low: 0
  • Measurement range high: 10 (because datasheet: 5Amp AC => 5VDC; that means 10Amp AC => 10VDC)

Now, the AC Current might be displayed at the RMS.

AC power

• To display the AC power consumption, please repeat the action before. The input scaling might be multiplied with the voltage 230VAC (because power = current * voltage)
• The input scaling of the RMS-MADC-868-V for power should be:
  • Measurement range low: 0
  • Measurement range high: 2300 (because datasheet: 5Amp AC => 5VDC; that means 10Amp AC => 10VDC => 10 multiplied by 230)

Now, the AC Power might be displayed at the RMS.

Time of operation
Also it is possible to count the time of operation of a monitored machine.

• Set an upper alarm limit of e. g. 0.1W of the power consumption, to detect when a machine turns on and off.
• Create a system measurement point of type “Alarm Time Counter”
  (Tools -> Setup -> Measuring points -> New -> System measuring point -> Type: Alarm time counter / Reset: Never / Element: Power or current consumption).
  It counts the time when the alarm is active, that means when the power is on.

If you have an interval of 1 min, than you measure the operation time in minutes.

Power consumption chart over the time:




An exemplarily layout of a climate chamber