Current Sensor for NI 9239

[lfpa15]

Hello,

I have a Compact Rio and I have NI 9239 module (Input +-10V, 24 bits). I would like to know if the following sensor is the rigth for the current measurement.

24 inch Revenue Grade Rope CT by AccuEnergy

• 120 mVac for every 1000 Aac on the primary at 60 Hz (100 mVac/1000 Aac at 50 Hz)
• High accuracy for revenue grade applications
• Wide frequency range means excellent choice for harmonics and power quality
• Wide current input range from 5A – 50,000A AC
• eGauge, Measurlogic, and AccuEnergy meter compatible without power supply requirement or integrator.
• Choice of 16″, 24″, 36″ or 47″ length

Thanks for your attention

[James_McN]

The obvious question is what do you need from it! But it looks well matched to the 9239.

Range: the 10V range gives you about 7Vrms corresponding to 58,000Arms (ish) so you have the full range of your actuator. Of course, if you only expect 50A then you aren't making the best use of the range of the 9239 and might get more accurate results with a different ratio CT.

Looking at the product online the one strange thing is it looks like the gain is non-linear with frequency. It says:

When using the Rogowski coil outside of 50/60 Hz, you can determine its output as follows: 2 mV * frequency per 1000A

That might mean some additional transforms on the harmonics if you are interested in them.