Your very welcome. Glad to be of service. We post these videos for you. Consider checking out the deals and discounts section of our channel for great tool savings. Have a great day and thanks for the comment.
still looking for a video that shows a failure, for example if A phase was connected to ground at the opposite cable ends, what would the meter read then?
Did you disconnect the ground wire from the system as well? I have used a megger before, but it’s been a long while. I remember isolating the phase conductors, but cannot recall if we isolated the ground as well. I am about to perform some testing on some suspect VFD cable to a span motor for a pivot bridge. I do not want to back feed voltage through the ground to the VFD. I won’t be reading insulation resistance of the ground conductor. I believe that is unnecessary since it does not carry load current.
So here you were testing brown to ground, does that mean on the other side the brown was spliced with the ground just like how you would do when checking for continuity?
Thanks for your question. As long as the equipment is in the off position, you can technically test it. You'll have to remember that if the feed is parallel, then you will be testing all wires of the same color at once. The best practice is to lift all wires and either tape them off, or have a spotter to assure no one gets shocked by touching the conductors. I hope this answered your question and i encourage you to ask any question any time! Have A Great Day!
The longer and larger the wire is, the more energy required to hold testing voltage. This results in longer testing times being needed. Also, the longer your wire is the more chance you have for minute damage. Thanks for the awesome comment and Have A Great Day!
No. You do not connect your phase conductors together. To read the resistance, each phase has to be completely isolated. So the end you are not connecting to your test instrument, should be isolated to be not connected to ground or to anything else. The tester will measure whatever leaks through. The maker of the video mentions isolating around 2:40 of this video.
Thank you for your comment. Don accurately answered this question. You want to lift the opposite end from any terminals and wrap with tape. This will give you an accurate insulation test as well as keep others from getting shocked.
Yes that is correct. The voltage also depends on the wire rating. If it's 600v rated, then we normally use 1000v for one minute. Thanks for the comment and Have A Great Day!
@@ElectricianToolDeals Is that correct? 1,000 volts for 600 volt wire? I usually use 500 volts for 600 volt wire. The wires I test are never more than 28 vdc or 115 ac. I mean, if the insulation is only rated to 600 volts then could you consider it failed at 1,000 volts? I'm not sure....just asking.
Thank you for the comment. That is due to the manufacturer wanting to keep the tester compact. They can achieve 1051v with less parts than a perfect 1000v. The difference in results is so minute that it doesn't register... this is the answer that fluke gave us. I hope this answers your question. Thanks for watching and HAVE A GREAT DAY!
This is not for a DIY project. We usually only megger when it's large wires, or as in my case today a douche of a General, who thinks that the wires are bad because some of the outer jackets were scuffed up. Not the insulation but the protective outer jacket.
You can use both sets of leads that come with the 1507 to mega the other lead you're talking about just has the test button on the lead there isn't anything wrong with using these clamps
@@ElectricianToolDeals your conductors you are testing….. if they have a cut in the insulation… yet none of the damaged area is touching anything like in free air…. It will still show compromised conductor?
@@chadhardwick9214 That is supposed to be the case. The amount of current that bleeds off that wire and onto the other wires should be larger therefore, giving you a lower reading. If you are doing testing and you have one wire reading significantly lower than the rest, then there should be cause for concern.
So go ahead and explain HOW the return reading gets to the megohmmeter if all conductors are insulated and only damage in one of the conductors. So, since your "green" EGC is insulated, explain HOW you get reliable readings when the return path to the meter is insulated and all raceways are nonmetallic and again all conductors are insulated. Physics say it is not possible but Megger, Fluke, AECM and so on all want you to think this is how megohmmeters work. Think about it.....if all conductors are insulated are you expecting the GREEN with perfect insulation to somehow ABSORB the leakage....through perfectly good insulation. Again not want MEGGER and FLUKE want to hear...........FYI- 100M is a NETA standard it is not what manufacturers say, ask me how I know.
Hello Paul, I know who you are and I know that you are far more qualified to speak on this than I am. All I will say is that, when you charge a wire with 1000v dc, the voltage creates a magnetic field around the wire, one positive and one negative. I believe the measurement you receive is based on the difference in the returned factor, and the factory set value on the meter. These 2 values are calculated based on a "proprietary formula" and the resistance is shown. But please educate me if I am incorrect. This is a rare opportunity for me to converse with someone of your intellect.
@@ElectricianToolDeals Greetings Fella. Just an Electrician Fella. Now, I have in various emails from megohmmeter manufacturers who state in the emails that without a conductive return path the megohm readings are useless. They were asked specifically if single insulated conductors are installed in a nonmetallic raceway and only one conductor is damaged and all other paths are insulated, would the megohmmeter readings be reliable and their answer is NO. They state a return path that is conductive must exist. I would love to think that capacitance and so forth would result in an osmosis effect on a mutual insulated conductor but in its just not possible. Now, give us a metallic return path, grossly contaminated insulation and so forth maybe..but not in normal installations I just don't buy into the hocuss pocuss. Still waiting for Megger, Fluke, Flir, and AEMC to convince me otherwise. Great video however and keep up the good work.
@@MasterTheNEC I definitely can believe that. We do it as part of the red tape on a job. I've always wondered how accurate it was. Thank you for the education 🙏 🙌 have an awesome day!
@@MasterTheNEC But isn't this like saying....if a tree falls in the forest does it make a sound? In other words, if it sits in a non conductive routing and the other insulations are good, ....the current will follow the path of least resistance down the wire. Even though that particular insulation might leaks, it has nowhere to leak to and so will operate "normally."
Good stuff! Thanks for the quick lesson. I'll be doing this at work, and this helps a lot 👍
Your very welcome. Glad to be of service. We post these videos for you. Consider checking out the deals and discounts section of our channel for great tool savings. Have a great day and thanks for the comment.
still looking for a video that shows a failure, for example if A phase was connected to ground at the opposite cable ends, what would the meter read then?
It'll be a while before I need to do more tests but I've had several fail. I'll make a failing video. Thanks for the comment.
Did you disconnect the ground wire from the system as well? I have used a megger before, but it’s been a long while. I remember isolating the phase conductors, but cannot recall if we isolated the ground as well.
I am about to perform some testing on some suspect VFD cable to a span motor for a pivot bridge. I do not want to back feed voltage through the ground to the VFD. I won’t be reading insulation resistance of the ground conductor. I believe that is unnecessary since it does not carry load current.
The ground also needs to be tested and isolated to verify no current leakage from phase to ground.
You won't need resistance of ground but you will need resistance of phases relative to ground
Excellent video. Thank you
Your very welcome. Feel free to cruise our channel if you like this type of content.
So here you were testing brown to ground, does that mean on the other side the brown was spliced with the ground just like how you would do when checking for continuity?
Thanks for the comment. No the other ends were covered with tape.
Each leg covered with tape? Not together? Is yes, than it wouldn't it matter r whichever cable it's tied to
Do you always have to disconnect the other end from whatever equipment and tape it off
Thanks for your question. As long as the equipment is in the off position, you can technically test it. You'll have to remember that if the feed is parallel, then you will be testing all wires of the same color at once. The best practice is to lift all wires and either tape them off, or have a spotter to assure no one gets shocked by touching the conductors. I hope this answered your question and i encourage you to ask any question any time! Have A Great Day!
It should be any different between 50 and 300 feet’s on the ohms reading?
The longer and larger the wire is, the more energy required to hold testing voltage. This results in longer testing times being needed. Also, the longer your wire is the more chance you have for minute damage. Thanks for the awesome comment and Have A Great Day!
Wait so do you tape the other end individually or do you for example put the brown and orange together and then test it like continuity?
No. You do not connect your phase conductors together. To read the resistance, each phase has to be completely isolated. So the end you are not connecting to your test instrument, should be isolated to be not connected to ground or to anything else. The tester will measure whatever leaks through.
The maker of the video mentions isolating around 2:40 of this video.
Thank you for your comment. Don accurately answered this question. You want to lift the opposite end from any terminals and wrap with tape. This will give you an accurate insulation test as well as keep others from getting shocked.
Thank you for your comment and excellent response.
How do you determine the value of resistant is good after measurement? I know you mention above 100 but does this value apply's to all test?
The passing resistance depends on the type of insulation on the wire.
Thanks dude
Your very welcome, thanks for the comment.
Do you know if there’s a standard for figuring out which voltage to use? For example: If your’e using a smaller wire.
1/0 and larger 1000v and smaller 500v
basic idea double the operating voltage. Eg if the cable is used for 230VAC then min 500VDC should be used for testing. Correct me if I am wrong.
Yes that is correct. The voltage also depends on the wire rating. If it's 600v rated, then we normally use 1000v for one minute. Thanks for the comment and Have A Great Day!
@@ElectricianToolDeals cheers mate
@@ElectricianToolDeals Is that correct? 1,000 volts for 600 volt wire? I usually use 500 volts for 600 volt wire. The wires I test are never more than 28 vdc or 115 ac.
I mean, if the insulation is only rated to 600 volts then could you consider it failed at 1,000 volts? I'm not sure....just asking.
Doing this tomorrowbwith rhe 1587 i believe. Hopefully all is good.
I'm sure you'll have no problem.
Thanks so much. ❤
Thanks for the comment.
If we are applying 1000 v why the instrument taking 1051 v ?
Thank you for the comment. That is due to the manufacturer wanting to keep the tester compact. They can achieve 1051v with less parts than a perfect 1000v. The difference in results is so minute that it doesn't register... this is the answer that fluke gave us. I hope this answers your question. Thanks for watching and HAVE A GREAT DAY!
I have referred to youtube for many DIY projects, but this seems well beyond DIY. Can’t think of a situation where someone would need to do this.
This is geared towards younger electricians.
This is not for a DIY project. We usually only megger when it's large wires, or as in my case today a douche of a General, who thinks that the wires are bad because some of the outer jackets were scuffed up. Not the insulation but the protective outer jacket.
@@billcamerlo7460 hahaha 😆
To test motors and compressors on your air conditioning system would be one!
@@EarlHaywardThat is a perfect example. This also could be used to test and type of power cord. Make sure its not hooked to a device though.
You are not using the proper leads. There is a different lead for doing megger testing. Notice the open spots above the red lead on the megger.
Thanks for the comment. These leads are the same leads that they use to calibrate these meggers.
You can use both sets of leads that come with the 1507 to mega the other lead you're talking about just has the test button on the lead there isn't anything wrong with using these clamps
Well now I feel like an asshole. Thanks for the education
Southern white guys get right to the point
Yes sir... thanks for the comment. Have A Great Day!
Confirmed it hurts if you touch the wire ends
Bwahahahahahaha yes sir it does. We have to be careful. 😁
@ElectricianToolDeals If only I seen this video 2 days ago I would have avoided a date with a stun gun 🤣
@@Jeff_Raids it definitely hurts... new guys might or might not be funny to watch...🤔🫣🤣
Knocked it in the dirt.
Hall Mark Jones Eric Thompson Deborah
Thanks for the comment.
I have a couple of questions…. If anyone is still on this thread….. probably dumb questions but nevertheless
Thanks for the comment. Go ahead with your questions.
@@ElectricianToolDeals your conductors you are testing….. if they have a cut in the insulation… yet none of the damaged area is touching anything like in free air…. It will still show compromised conductor?
If that makes any sense at all
@@chadhardwick9214 That is supposed to be the case. The amount of current that bleeds off that wire and onto the other wires should be larger therefore, giving you a lower reading. If you are doing testing and you have one wire reading significantly lower than the rest, then there should be cause for concern.
So go ahead and explain HOW the return reading gets to the megohmmeter if all conductors are insulated and only damage in one of the conductors. So, since your "green" EGC is insulated, explain HOW you get reliable readings when the return path to the meter is insulated and all raceways are nonmetallic and again all conductors are insulated. Physics say it is not possible but Megger, Fluke, AECM and so on all want you to think this is how megohmmeters work. Think about it.....if all conductors are insulated are you expecting the GREEN with perfect insulation to somehow ABSORB the leakage....through perfectly good insulation. Again not want MEGGER and FLUKE want to hear...........FYI- 100M is a NETA standard it is not what manufacturers say, ask me how I know.
Hello Paul,
I know who you are and I know that you are far more qualified to speak on this than I am. All I will say is that, when you charge a wire with 1000v dc, the voltage creates a magnetic field around the wire, one positive and one negative. I believe the measurement you receive is based on the difference in the returned factor, and the factory set value on the meter. These 2 values are calculated based on a "proprietary formula" and the resistance is shown. But please educate me if I am incorrect. This is a rare opportunity for me to converse with someone of your intellect.
@@ElectricianToolDeals Greetings Fella. Just an Electrician Fella. Now, I have in various emails from megohmmeter manufacturers who state in the emails that without a conductive return path the megohm readings are useless. They were asked specifically if single insulated conductors are installed in a nonmetallic raceway and only one conductor is damaged and all other paths are insulated, would the megohmmeter readings be reliable and their answer is NO. They state a return path that is conductive must exist. I would love to think that capacitance and so forth would result in an osmosis effect on a mutual insulated conductor but in its just not possible. Now, give us a metallic return path, grossly contaminated insulation and so forth maybe..but not in normal installations I just don't buy into the hocuss pocuss. Still waiting for Megger, Fluke, Flir, and AEMC to convince me otherwise. Great video however and keep up the good work.
@@MasterTheNEC I definitely can believe that. We do it as part of the red tape on a job. I've always wondered how accurate it was. Thank you for the education 🙏 🙌 have an awesome day!
@@MasterTheNEC But isn't this like saying....if a tree falls in the forest does it make a sound? In other words, if it sits in a non conductive routing and the other insulations are good, ....the current will follow the path of least resistance down the wire. Even though that particular insulation might leaks, it has nowhere to leak to and so will operate "normally."
@@rael5469 none of that makes any sense....none