Dear Justwell ! Thank you very much for these kind words. It is for you and people like you that I make this videos for. Thank you for using then and apreciating :) All the best in New Year
Thank you for your comprehensive presentation I really appreciated so, I have one question please could tell me what is the different between Tan Delta test and partial discharge? With thanks
Tan delta is a measurement that shows you the overall, statistical value of the conductivity of your insulator. While PD is measuring the sparks (microsparks) in the insulation which also gives you an insight in the status of the insulation. Both measurements show the status of the insulation, but each one from its “own perspective”. Like in medicine, for some things CT is better and for some Magnetic Resonance for example. This is answer in short, but many other things can be added
Hi Subodha ! Thank you for the suggestion but I do not have enough experience with Cable testing of PD, so I would not feel comfortable talikg about something I do not know much. If that chances I will make a video. Thank you for understanding.
hi it's so interesting, but because my english isn't very good, i'm asking if it's possible to find all these videos performed by you in french. thanks a lot.
Slimane Oukil I regretfully do not speak French, but in our company there are French speaking people and they plan to translate this presentations. Please send me your email and I can send it to you when it is done.
By measuring the phase shift between the voltage we generate and the current we measure. Voltage is at 0 degrees, currently should be ideally 90 degrees but it is almost always less. For example 89.71 degrees. From that the device calculates how much resistive and how much capacitive current is being absorbed by the device under test. Let me know it this is clear.
The answer would not fit into few thousand characters that I have here at my disposition. I can only tell you that empirically it is proven that AC is repeatable more than DC. You can do a Polarisation Index test (DC) on Trafo 3 times and you will get 3 different values. If you do a Tan Delta (AC test) the result should be the same up to 2nd or 3rd decimal. That is the fact of the matter. I would also like to add one thing that might explain why is it like that - when you use DC voltage while testing insulation - when the test in done - there are much more free electrons left in the insulation then if you were to use AC source. The presence of the free electrons could eventually cause the PD discharge. It is so because if you have a void in the insulation and no free electrons - then you do not have PD. But with a free electron available (which is often the case when doing a DC test) one can trigger PD. I guess this explains more why DC is more then destructive then AC but I wanted to add this comment because it explains a bit the mechanism why DC is to more avoided. I am not saying the DC is not a god way to do tests, I am just saying that DC presents more potential danger to further damage the insulation. Hope it helps.
@@sheppo17 Excellent, but why now most of the insulation testers are DC, most info I found recommend DC I thought DC was better as applying a continuous voltage also for cables and for more safety for the operator. What do you recommend as testing for insulation?. I had a tan delta tester a Chinese one HYGS it was small size and nice, I sold it but I will get another one a 10kV as the 12kV is 1Kusd more, what is the difference in higher versus lower tan delta voltage testing?. What would be good to do a complete transformer test? insulation in DC and AC, TTR and Tan Delta or just tan delta? Thanks.
@@electronicatutorial Many companies worldwide work with a DC test voltage. The main reason from the past is that the test equipment used is much smaller and handier than comparable AC test equipment. Until the turn of the millennium, the effort required for AC testing was much greater than for DC. But, this has changed considerably. However, there are now a few companies that can carry out AC voltage tests at 50/60 Hz and do not need a whole truck to do so, and these are comparable to the test requirements of cable manufacturers and IEC-IEEE regulations. The advantage of the 50/60 Hz test is that, on the one hand, unlike VLF, DAC, Cos Rec, this is a non-destructive measuring method and can therefore be repeated several times.
this is the best explanation I've come across. Thank you a lot
Thank you Jason :) it really means a lot !!!
Very good explanation Sir thank you so much. it's nice that you have communicated your explanation with real-life examples.
Dear Justwell ! Thank you very much for these kind words. It is for you and people like you that I make this videos for. Thank you for using then and apreciating :)
All the best in New Year
Very informative !
Thank you !
Thanks for the video.
You are most welcome
Nice sir .. Please upload more videos on electrical Testing topics
Just published sir. Please check and let me know your thoughts.
Thank you for your comprehensive presentation I really appreciated so, I have one question please could tell me what is the different between Tan Delta test and partial discharge?
With thanks
Tan delta is a measurement that shows you the overall, statistical value of the conductivity of your insulator. While PD is measuring the sparks (microsparks) in the insulation which also gives you an insight in the status of the insulation. Both measurements show the status of the insulation, but each one from its “own perspective”. Like in medicine, for some things CT is better and for some Magnetic Resonance for example. This is answer in short, but many other things can be added
What is the frequency of test voltage to find out micro level
measurement of tan delta
We test at nominal frequency, plus minus 0.5 to 2 Hz.
can you kindly do some lectures on HVUG cable testing as well? especially about XLPE and LPOF cables
Hi Subodha ! Thank you for the suggestion but I do not have enough experience with Cable testing of PD, so I would not feel comfortable talikg about something I do not know much. If that chances I will make a video. Thank you for understanding.
hi
it's so interesting, but because my english isn't very good, i'm asking if it's possible to find all these videos performed by you in french.
thanks a lot.
Slimane Oukil I regretfully do not speak French, but in our company there are French speaking people and they plan to translate this presentations. Please send me your email and I can send it to you when it is done.
Sir, Current is just current only.... How do we know which is capacitive and which is resistive current while testing?
By measuring the phase shift between the voltage we generate and the current we measure. Voltage is at 0 degrees, currently should be ideally 90 degrees but it is almost always less. For example 89.71 degrees. From that the device calculates how much resistive and how much capacitive current is being absorbed by the device under test. Let me know it this is clear.
Hi ... could you please explain CB tan delta test?
Please explain
LA tan delta
What mode, how much value valid for ok
Hi Akash, please clarify what do you mean by LA ?
Why AC is more repeatable than DC test?
The answer would not fit into few thousand characters that I have here at my disposition. I can only tell you that empirically it is proven that AC is repeatable more than DC. You can do a Polarisation Index test (DC) on Trafo 3 times and you will get 3 different values. If you do a Tan Delta (AC test) the result should be the same up to 2nd or 3rd decimal. That is the fact of the matter. I would also like to add one thing that might explain why is it like that - when you use DC voltage while testing insulation - when the test in done - there are much more free electrons left in the insulation then if you were to use AC source. The presence of the free electrons could eventually cause the PD discharge. It is so because if you have a void in the insulation and no free electrons - then you do not have PD. But with a free electron available (which is often the case when doing a DC test) one can trigger PD. I guess this explains more why DC is more then destructive then AC but I wanted to add this comment because it explains a bit the mechanism why DC is to more avoided. I am not saying the DC is not a god way to do tests, I am just saying that DC presents more potential danger to further damage the insulation.
Hope it helps.
@@sheppo17 Excellent, but why now most of the insulation testers are DC, most info I found recommend DC I thought DC was better as applying a continuous voltage also for cables and for more safety for the operator. What do you recommend as testing for insulation?.
I had a tan delta tester a Chinese one HYGS it was small size and nice, I sold it but I will get another one a 10kV as the 12kV is 1Kusd more, what is the difference in higher versus lower tan delta voltage testing?. What would be good to do a complete transformer test? insulation in DC and AC, TTR and Tan Delta or just tan delta? Thanks.
@@electronicatutorial Many companies worldwide work with a DC test voltage. The main reason from the past is that the test equipment used is much smaller and handier than comparable AC test equipment. Until the turn of the millennium, the effort required for AC testing was much greater than for DC. But, this has changed considerably.
However, there are now a few companies that can carry out AC voltage tests at 50/60 Hz and do not need a whole truck to do so, and these are comparable to the test requirements of cable manufacturers and IEC-IEEE regulations.
The advantage of the 50/60 Hz test is that, on the one hand, unlike VLF, DAC, Cos Rec, this is a non-destructive measuring method and can therefore be repeated several times.