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Multimeter | Clamp meter | Insulation Resistance Tester | Panel Meter | Oscilloscopes | Test leads & Accessories | Software Updates => Bench-top Oscilloscope & Handheld scope meter => Topic started by: Kiriakos GR on November 04, 2022, 05:21:32 PM

Title: Proper use of Oscilloscope for load testing - setup of voltage & current probe
Post by: Kiriakos GR on November 04, 2022, 05:21:32 PM
Today I was up to ACV load testing by the use my Oscilloscope along of differential voltage probe and AC/DC current probe.

I did connect everything, but at the oscilloscope screen voltage phase and current phase, these was looking as reversed.
I did double check Oscilloscope settings, everything seemed correct and I was scratching my head for some time.
Current probe this has an arrow mark at the Jaws, therefore I did that connection correctly.  :) 

But I was using RED and Black test leads and banana plugs,  and the differential volts probe this has also RED and Black banana plugs.
And this detail did not helped me to detect my error, fast enough.  :P 

Today's lesson learned:
Make sure that both voltage and current probe, are both in synchronization with active phase (polarity check).
Or else you see everything with a not easy to explain phase error.  ;D 

To make your life easier, confirm proper phase synchronization by the use of halogen lamps as load. 
Title: Re: Proper use of Oscilloscope for load testing - setup of voltage & current probe
Post by: overvolt on November 05, 2022, 10:11:44 PM
Behind these screenshots they are tools worth 3000 Euros.
I have never see before your oscilloscope to be so busy.  ;D

Power measurements with an Oscilloscope this is advanced measurement for electrician engineers to execute.
It is justified of you to gain a new pack of experiences as you do elevate your own skills.  ;)   
Title: Re: Proper use of Oscilloscope for load testing - setup of voltage & current probe
Post by: Andrew-88 on November 06, 2022, 03:52:34 PM
First screenshot represents voltage & current at 180 degree shift.
Second and third = 0 Degree = now corrected.

Its a fact that in Greece, only at university they might have oscilloscopes and probes for such visual demonstration.   
Imagine how many things can go wrong (wiring) if this was a three phase power analyzer? LOL
   
Equal setup to oscilloscope with six probes.  ;)
Title: Re: Proper use of Oscilloscope for load testing - setup of voltage & current probe
Post by: Kiriakos GR on November 06, 2022, 04:47:47 PM
Imagine how many things can go wrong (wiring) if this was a three phase power analyzer? LOL
   
Equal setup to oscilloscope with six probes.  ;)

Most three phase power analyzer, they include wiring test mode, and they deliver messages, in case of wrong connection.
When wiring test this is a Pass, then you may use them.
Oscilloscopes does not include foolproof wiring tests, you should do all wiring inspections of your own. 

All active current probes they include by design 0,5 to 1 degree shift,  but the Oscilloscope cannot visualize such a difference.   
All active current probes they also include 200mV of noise due their electronic circuit,  if a screenshot demonstrates a clean current waveform this be equally clean as is the voltage, then this is taken due power analyzer with direct current input = shunt.     

Example: The 80 PLUS certificates