PicoScope 7 Automotive
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Is 4425 suitable for Industry mains voltage?
Is 4425 suitable for Industry mains voltage?
I have an Picoscope 4425 which I use for automotive work. I am exploring the option to use it in Industry for the following application.
Example isolated grid: one diesel generator, 690Vac rms 976V peak to peak, insulated system, 60hz, subtransient short circuit capacity of 25kA and peak short circuit of 62.5kA.
At rated speed, the diesel generator must be able to absorb 0% to 50% and 50% to 100% of the rated output power, and the voltage drop must not exceed -15% for 1.5s and frequency drop must not exceed -10% for 5s.
Similar, at the entire load rejection, from 100% to 0%, voltage must not exceed +20% for 1.5s.
These tests are done at the new construction of the plant and every time a diesel generator is replaced, upgraded, or AVR or governor replaced.
From what I can research with Pico, a 4444 differential oscilloscope would be the choice to go.
I am looking now into using 4425 with TA057 CAT III differential probe.
1.Is this combination doable? I would intent to connect the probe between two phases, as it would give me phase to phase voltage and frequency.
2. How to protect for the short-circuit current capacity of the grid? I can connect behind some busbar fuses, but I find the input leads sprung hooks a bit .... doubtful.
3. Can Picoscope standard software plot me the frequency and voltage drops? With math channels?
4. For creating a plot curve, I believe 4425 is fast enough, it is very similar in characteristics with the 4444. Is this correct?
3. I have the feeling I am missing something, but what?
4. Can I use a second channel for other 2 phases? Using differential probe, I believe max output is 7V (14V peak to peak between two channels?), which is already on the safe side of 30V floating 4425 inputs.
5. Does it make a difference if another grid has generator neutral grounded?
6. Any safety items I am obviously missing?
Example isolated grid: one diesel generator, 690Vac rms 976V peak to peak, insulated system, 60hz, subtransient short circuit capacity of 25kA and peak short circuit of 62.5kA.
At rated speed, the diesel generator must be able to absorb 0% to 50% and 50% to 100% of the rated output power, and the voltage drop must not exceed -15% for 1.5s and frequency drop must not exceed -10% for 5s.
Similar, at the entire load rejection, from 100% to 0%, voltage must not exceed +20% for 1.5s.
These tests are done at the new construction of the plant and every time a diesel generator is replaced, upgraded, or AVR or governor replaced.
From what I can research with Pico, a 4444 differential oscilloscope would be the choice to go.
I am looking now into using 4425 with TA057 CAT III differential probe.
1.Is this combination doable? I would intent to connect the probe between two phases, as it would give me phase to phase voltage and frequency.
2. How to protect for the short-circuit current capacity of the grid? I can connect behind some busbar fuses, but I find the input leads sprung hooks a bit .... doubtful.
3. Can Picoscope standard software plot me the frequency and voltage drops? With math channels?
4. For creating a plot curve, I believe 4425 is fast enough, it is very similar in characteristics with the 4444. Is this correct?
3. I have the feeling I am missing something, but what?
4. Can I use a second channel for other 2 phases? Using differential probe, I believe max output is 7V (14V peak to peak between two channels?), which is already on the safe side of 30V floating 4425 inputs.
5. Does it make a difference if another grid has generator neutral grounded?
6. Any safety items I am obviously missing?
Re: Is 4425 suitable for Industry mains voltage?
Please email these question directly to the support team support@picotech.com
As safety is paramount we would not like to recommend an approach on a public forum that could be misinterpreted by someone else with potentially dangerous consequences.
As safety is paramount we would not like to recommend an approach on a public forum that could be misinterpreted by someone else with potentially dangerous consequences.
Martyn
Technical Support Manager
Technical Support Manager