Hi Speed Recorder Current Clamp

[ThePunisher]

I am looking into a Fluke i2000flex Felxible Current Probe which will be used with a HIOKI 8860 High Speed Recorder.

We are going to use the recorder to measure transformer inrush currents. We estimate the inrush current to be around 1500A peak. The Current Probe (current clip-ons) are rated for 2000A with a non-destructive current rating of 4000A.

However, in the specs, it says that that current measured may not contain any DC component.

The transformer inrush have both harmonic and DC components that decays almost instantly on small transformers.

What type of test set up or current sensor I need to measure the inrush current inclusive of both harmonic and DC component? Can I measure the AC peak, DC component and harmonic current at a particular cycle that corresponds to the peak and just take the sum of the three?

 

[electricpete]

Hall effect of course meausred dc, but can get expensive for high current ranges.

The error for ct's and typical magnetic clamp-ons is associated with an L/R decay of the dc component (where L is associated with magnetizing inductance and R associated with resistance of secondary winding and burden)... it will likely not be a huge error for the 1st peak if that's what you're looking for.





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[ScottyUK]

That Fluke probe is a Rogowski coil based design, which are inherently incapable of sensing DC. As David says, a Hall Effect probe is probably the best solution. LEM have some which reach up to several kA, my memory says about 6 - 8kA or so.


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If we learn from our mistakes I'm getting a great education!

 

[PQDoctor]

LEM is Fluke, so you can consult with your provide.

Another excellent source is Chauvin Arnoux. Go to

http://www.aemc.com

and select "Current Probes".

My Power Quality and Energy Efficiency blog:

http://www.PowerQualityDoctor.com

 

[ScottyUK]

LEM Instruments were bought by Fluke. The parent company LEM is not part of Fluke, and the products I'm talking about aren't marketed or manufactured by Fluke.


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If we learn from our mistakes I'm getting a great education!

 

[ThePunisher]

If I have a Hall Effect CT connected to the HIOKI (assuming there is a provision and a channel is assigned to it).

Assuming also, that the total harmonic current is measured on that particular cycle.

Can I say that the total transformer inrush current at a particular cycle will be the peak AC current measured (at particular cycle)+ DC Current(at particular cycle) + Harmonic current (at particular cycle)?