Thanks for taking the time to share your knowledge. As an adult learner this is one of the best explanations of IR that I've seen on RUclips. Looking forward to Part 2
I just wanna say your style of presenting and teaching is just so good. That part about watching your device's resolution and being careful not to misread or misinterpret what your values are is such a common mistake and I'm glad you pointed it out.
Great graphics! Thank you. IR testing does not give an indication of conductor corrosion or if its ability to conduct electricity is adequate right? Is this test enough to give tenants confidence that main cables powering a house is satisfactory?
3:07 I have seen that happen. A screw through a floor board was too long and went all the way into a wire bundle. Failed the megger check. We had to start pulling floor boards up and go hand over hand until we found the problem.
I tested a single phase hvac pump at 15 mega ohms to ground on each leg. A short circuit was present but could not varify with meter. I also tested legs between each other and the ohms tested correct against factory spec. When you smacked the housing with a rubber mallet the short stopped. I still dont understand why i could not see the short to ground with meter when it was clearly shorted to ground.
In aircraft maintenance our fault isolation manual often tells us to simply change an electrical component. They do not say to meggar it or test it. I assume that's because of exactly what you are talking about....that it appears to test good but fails under load. I think the manual writers came to realize that certain electrical components aren't really testable .....just replace them and let the rebuild, shop sort it out.
Question: When a voltage is not specified for the megger check, and the 115 vac wires are rated at 600 volts......which voltage should be set on the megger? I always assumed that 500 volts should be used since 1,000 volts is beyond the wire's rating. Is that logical?
Thank you for your efforts in producing this, it's appreciated. Just like your previous ones, it's very well presented and full of theory and real world content. I'm looking forward to the next episode, hopefully not too long away, as I am keen to see where you're last scenario of false positives etc is going as the AV pictures made me think where you were going. Great production. I've got the 1741+, how do you rate it?
Hi Olly , thanks for the nice comment. Im working on the next one now so hopefully in a few days. 1741+ is a good meter. Its had to go back to Megger though, as it had a fault. The two lead low current test, is a great function. The lead is the one with the test button on it. You need to press the test button when doing IR so using the probe with the test button makes it easier.
Another safety tip.......first.... follow published procedures. But also totally remove power from a circuit before touching it. Unplug the power cord or power supply ! Unplugging the power is the only real way to make sure the circuit is safe. Plus be aware that some systems have battery power also, with a hot battery bus. In some cases you must disconnect the battery as well as unplugging the power cord.
Thanks for the comment w w. That arc was caused by two 1.5v batteries. It did go through a voltage multiplier though to get enough voltage to cause that effect. I wanted to highlight the fact is was battery only, as I did not want people to think it was mains power, and try it for themselves.
Hi Leyton. RCDs are sensitive devices, and some more than others. On a ramp test, which is a test which gradually increases the 'tripping current' I generally find a 30mA RCD operates around 25mA.
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Thanks for taking the time to share your knowledge. As an adult learner this is one of the best explanations of IR that I've seen on RUclips. Looking forward to Part 2
Thanks GrumpyGrampa, Its kind comments like yours, that makes the work I put into these worthwhile
@@JPElectricPlease what is the test during for the IR.
At what instance do you injected more than 500V
I just wanna say your style of presenting and teaching is just so good. That part about watching your device's resolution and being careful not to misread or misinterpret what your values are is such a common mistake and I'm glad you pointed it out.
Thank you for watching appreciate your comments
Wow! This is video very informative and the best tutorial on the topic for me so far. I really appreciate it. Thanks for sharing it with us.
Excellent explanation of insulation resistance testing, and graphics
Thanks David , really appreciate your comment
AMAZING video
Thanks for watching electricalstuff259
Thanks for this very instructional video, well layed out and easy to follow :)
Thanks Ronaldo. Really appreciate it.
Amazingly good instruction
brilliant explanation!
Thank you knoxieman
Great graphics! Thank you. IR testing does not give an indication of conductor corrosion or if its ability to conduct electricity is adequate right? Is this test enough to give tenants confidence that main cables powering a house is satisfactory?
Beautiful presentation
Thank you awalsakibmohammed3985
شكرا فعلا استفدت
What is the test voltage needed for a 4160 3 phase motor, and what is the minimum acceptable IR for that ?
Look it up in the appropriate standard. IEEE 43 is a good one if you don't know.
3:07 I have seen that happen. A screw through a floor board was too long and went all the way into a wire bundle. Failed the megger check. We had to start pulling floor boards up and go hand over hand until we found the problem.
So useful, thanks
Thanks very much J3envenuto
I tested a single phase hvac pump at 15 mega ohms to ground on each leg. A short circuit was present but could not varify with meter. I also tested legs between each other and the ohms tested correct against factory spec. When you smacked the housing with a rubber mallet the short stopped. I still dont understand why i could not see the short to ground with meter when it was clearly shorted to ground.
In aircraft maintenance our fault isolation manual often tells us to simply change an electrical component. They do not say to meggar it or test it. I assume that's because of exactly what you are talking about....that it appears to test good but fails under load. I think the manual writers came to realize that certain electrical components aren't really testable .....just replace them and let the rebuild, shop sort it out.
👍👍
Question: When a voltage is not specified for the megger check, and the 115 vac wires are rated at 600 volts......which voltage should be set on the megger? I always assumed that 500 volts should be used since 1,000 volts is beyond the wire's rating. Is that logical?
Thank you for your efforts in producing this, it's appreciated. Just like your previous ones, it's very well presented and full of theory and real world content. I'm looking forward to the next episode, hopefully not too long away, as I am keen to see where you're last scenario of false positives etc is going as the AV pictures made me think where you were going. Great production. I've got the 1741+, how do you rate it?
Also..... what red lead are you using with the crocodile clip for the resistor clip?
Hi Olly , thanks for the nice comment. Im working on the next one now so hopefully in a few days. 1741+ is a good meter. Its had to go back to Megger though, as it had a fault. The two lead low current test, is a great function. The lead is the one with the test button on it. You need to press the test button when doing IR so using the probe with the test button makes it easier.
Thanks very helpfull
Thanks ELEKTROJEN, appreciate the comment
Nice graphics what software do you use for that?
Hi Math Man, I use illustrator and photoshop.
Another safety tip.......first.... follow published procedures. But also totally remove power from a circuit before touching it. Unplug the power cord or power supply ! Unplugging the power is the only real way to make sure the circuit is safe. Plus be aware that some systems have battery power also, with a hot battery bus. In some cases you must disconnect the battery as well as unplugging the power cord.
Very interesting, surprised to see arcing of two 1.5v batteries.
Thanks for the comment w w. That arc was caused by two 1.5v batteries. It did go through a voltage multiplier though to get enough voltage to cause that effect. I wanted to highlight the fact is was battery only, as I did not want people to think it was mains power, and try it for themselves.
why would 23mA trip a 30mA rcd?
Hi Leyton. RCDs are sensitive devices, and some more than others. On a ramp test, which is a test which gradually increases the 'tripping current' I generally find a 30mA RCD operates around 25mA.
Thank you for your guide very important
Thanks for watching and commenting michealtran3636