Love this thanks for being willing to put yourself out there pretty brave! I would hope that one day you’re willing to walk through some PF/DF results from transformers and just talk about what to look for instead of just pushing buttons lol. Thanks brotha
Great video! Although we short the windings during Megger so that we can transition immediately to Power Factor test. Can you talk about negative insulation power factor too? I've read some literatures about it but I'm not sure if I fully understood them. Cheers!
That's a good point. It really shouldn't affect the megger readings one way or the other. If your power factor result is negative in the context of an insulation power factor test, it means the reading is more inductive than capacitive. Current flowing through/out of the winding under test is leading the voltage (remember ELI the ICE man). I'm not the all saying guru about every type of transformer, but every time I've seen a negative PF it's been because we hooked up the test set wrong, something wasn't grounded, or there was an internal winding issue like a bad DETC.
@testingtechtips I see alot.of people say they take advantage of already having their windings shorted and do PF and megger back to back. Do you worry about megger magnetize your windings and effected your SFRA due to megger being a DC test?
@TrevorGoochFishing yes, absolutely. SFRA is a very sensitive test and performing Megger or winding resistance will skew your results. Winding resistance definitely has a more drastic effect but megger can as well.
Love this thanks for being willing to put yourself out there pretty brave! I would hope that one day you’re willing to walk through some PF/DF results from transformers and just talk about what to look for instead of just pushing buttons lol. Thanks brotha
I want to cover that too! It's definitely on the list.
great great vid! thanks and congrats!!
Thanks for watching!
Appreciate you for this 🙏
Happy to help!
Love the video! Well done. Keep it coming.
Thanks, will do!
Great video! Although we short the windings during Megger so that we can transition immediately to Power Factor test.
Can you talk about negative insulation power factor too? I've read some literatures about it but I'm not sure if I fully understood them. Cheers!
That's a good point. It really shouldn't affect the megger readings one way or the other.
If your power factor result is negative in the context of an insulation power factor test, it means the reading is more inductive than capacitive. Current flowing through/out of the winding under test is leading the voltage (remember ELI the ICE man). I'm not the all saying guru about every type of transformer, but every time I've seen a negative PF it's been because we hooked up the test set wrong, something wasn't grounded, or there was an internal winding issue like a bad DETC.
I've always shorted my windings with Megger.
There's nothing wrong with that.
@testingtechtips I see alot.of people say they take advantage of already having their windings shorted and do PF and megger back to back. Do you worry about megger magnetize your windings and effected your SFRA due to megger being a DC test?
@TrevorGoochFishing yes, absolutely. SFRA is a very sensitive test and performing Megger or winding resistance will skew your results. Winding resistance definitely has a more drastic effect but megger can as well.
Because math!!! I say that all the time 😂😂😂
🤣 no one likes that answer but that's the way it is!
So you’re saying this will be on the test?
Lol the formulas are on the cheat sheet they give you so... maybe?