Megohm testing

[electricalperson]

We had no problems pulling it,it pulled easily, and I checked everything with a regular ohm meter, saw no problems.

we have gotten 500 mcm cable brand new that had an insulation problem in it. a few days after it was pulled in and energized it blew up. no one had a megger at the time to test it

 

[76nemo]

We had no problems pulling it,it pulled easily, and I checked everything with a regular ohm meter, saw no problems.

With ALLLLLLLLLLLLLLL due respect, you should follow up more on training with Insulation testing. With that last statement, I can see you are missing the concept.

 

[electricalperson]

Chris, do you have a link to the spreadsheets by Megger? I see their cards, but they suck. I have no business saying that, excuse me.

I like Time/Date, V, S/PI/DAR, Temerature/Humidity, what instrument, what machine, and notes, to start with. I don't want a plotting graph that I can see in my head. If you look in one ear, you can see out through thee other

I just looked to no prevail. I am not one to "surf" with a goal in mind, it frustrates me, and rattles my cobwebs Are you talking of the Insulation tests and Hi Pot cards???

i dont have any spreadsheets i have cards that came with the MJ159 and i believe that pdf on biddlemegger.com is the same as the cards you can use them to see a trend in insulation failure

 

[electricalperson]

With ALLLLLLLLLLLLLLL due respect, you should follow up more on training with Insulation testing. With that last statement, I can see you are missing the concept.

you have no idea on how many electricians i know that swear that an ohm meter is just as good as a megger. "dont worry i checked it with an ohmmeter you dont need a megger"

 

[76nemo]

you have no idea on how many electricians i know that swear that an ohm meter is just as good as a megger. "dont worry i checked it with an ohmmeter you dont need a megger"

Ask them if you can throw 1000V's to them, scratch that, this will get deleted, and rightly so...............

 

[electricalperson]

Ask them if you can throw 1000V's to them, scratch that, this will get deleted, and rightly so...............

i never been shocked by a megger. does it hurt bad?

 

[journeymenelctric@msn.com]

Thats why Im asking, is infinity the only good reading or is less okay on longer wires. I dont know.

 

[electricalperson]

Thats why Im asking, is infinity the only good reading or is less okay on longer wires. I dont know.

in a 60 second test infinity is great and you want to see that when testing wires but anything over 50megaohms in a 60 second test is good. but new wire should be infinity

 

[hillbilly1]

Make sure you have the wires clear on both ends, as if you left them connected, you are megging the equipment that you are connected to also. Ground fault controls also feed from the line side of the switch also. If testing while connected be sure to remove the fuses protecting the GFC.

 

[electricalperson]

you should get the fluke 1507. it has a range of 50 - 1000v , 10Gohm range, automatic DAR/PI function and a compare function where you set the tester to lets say 50Mohms and the wire will either pass or fail with an indicator light

 

[76nemo]

i never been shocked by a megger. does it hurt bad?

Never done it, wouldn't do it to my worst enemy, the ex:grin: I don't fool around with electricity when it comes to push and shove. I have heard that crap, and it doesn't sit well with me. I like my Kool-Ade, there isn't enough Kool-Ade around to challenge anyone to that kind of stupidity. Since I have been using them, they have had an auto-discharge. I know of a guy who would wear dissipative shoes in an electronics facility that would get nailed with 1500V Hi-Pot, 10 mA cut. He was too good to use the mat, as hungover as he would be, it looked pretty d*mned eye-opening to me

 

[weressl]

you have no idea on how many electricians i know that swear that an ohm meter is just as good as a megger. "dont worry i checked it with an ohmmeter you dont need a megger"

Wheelllll just because somebody says they are 'electricians' that ain't makes them so........

 

[electricalperson]

Never done it, wouldn't do it to my worst enemy, the ex:grin: I don't fool around with electricity when it comes to push and shove. I have heard that crap, and it doesn't sit well with me. I like my Kool-Ade, there isn't enough Kool-Ade around to challenge anyone to that kind of stupidity. Since I have been using them, they have had an auto-discharge. I know of a guy who would wear dissipative shoes in an electronics facility that would get nailed with 1500V Hi-Pot, 10 mA cut. He was too good to use the mat, as hungover as he would be, it looked pretty d*mned eye-opening to me

that must of cured his hangover pretty quick. ac hipot and thumpers are a whole differnt ballgame. those things are dangerous

 

[76nemo]

Thats why Im asking, is infinity the only good reading or is less okay on longer wires. I dont know.

Start here, there is no such thing as "infinity", that just goes beyond what your meter will read, that's infinity to the meter. Given the right sources, you or anyone can break down anything.

 

[Pierre C Belarge]

I am using a A.W. Sperry Meg-o-volt series 530 which is 1000 volts, it uses 6 AA batteries

There are too many variables unknown in his testing first off for any rash decisions...


Also, notice he tested with 1000volts, that will also contribute towards a lower reading.

I myself would not be happy with a 40 Mohm reading with new conductors, so there may be some issues. Lets also remember his time sequence was only 15 sec for the testing.

Like I mentioned, not enough credible info to make a real credible answer.

 

[76nemo]

Thats why Im asking, is infinity the only good reading or is less okay on longer wires. I dont know.

First thing is FIRST. I salute you for your question and the strive to learn. I want to show you something. I don't want the regulars to get tee'd with me, this is the 3rd time I have posted a link to this, so please ground the comments.

If you are working with three phase, and you have a phase to phase, or phase/ground fault, in the wrong scenario you are most likely not going to survive it, or not return to work as an electrician. Some may say this is extreme, someone will say this could of been not so drastic if he had the right PPE, and he will tell you the same. That IS NOT my point, my point to you is this......... WITH ALLLLLLLLLLLL due respect, you energized a line that should of been yanked as soon as you got your results, or questioned by a senior member, and a different tester.

This accident did not occur due to insulation leakage, it was something entirely different. I would like for you to take a moment and watch this closely. Doing insulation testing on old motors and trannies can be one thing. Energizing new pulls after not having them checked properly could possibly result in this:


http://www.youtube.com/watch?v=3oyohKmeNpE



Don't EVER for one second think that couldn't to you!!!!!!!!!!!!!!!!! EVER!

Just FYI.

 

[mdshunk]

I zapped myself with a megger at 500 and 1000 volts. Matter of fact I'm pretty sure I did it more than once. More of a surprise than actual pain. Sorta like those joke pens that shock you when you press the button to get the tip to come out.

 

[76nemo]

I zapped myself with a megger at 500 and 1000 volts. Matter of fact I'm pretty sure I did it more than once. More of a surprise than actual pain. Sorta like those joke pens that shock you when you press the button to get the tip to come out.

Better than coffee, eh????

 

[mdshunk]

Better than coffee, eh????

No, I can't really recommend it. Just wanted to know what it would be like, is all.

 

[76nemo]

No, I can't really recommend it. Just wanted to know what it would be like, is all.

Guess that's in the category of "non-destructive" cutting:grin: