How do you Mega test wires?
- Thread starter bigjohn67
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bphgravity
Senior Member
- Location
- Florida
Re: How do you Mega test wires?
I am certain the manufacturer provided instructions on how to operate the megohmeter. Please review that for specifics.
Basically, megohmeters can perform many different tests. Insulation spot test, dielectric absorption, insulation step voltage, etc... Due to the fact that leakage current of insulation can be from many aspects such as conductive leakage, capacitive leakage, and surface leakage, one or more tests may be required to understand the total aspect of the insulation.
In some cases, external connections are required through resistors or other components for proper testing. But for general insulation resistance, connection between any two leads or from any lead to ground is all you need to do.
Many manufacturers will provide a "rule of thumb" index for allowable leakeage current on typical electrical systems and motor applications.
I am certain the manufacturer provided instructions on how to operate the megohmeter. Please review that for specifics.
Basically, megohmeters can perform many different tests. Insulation spot test, dielectric absorption, insulation step voltage, etc... Due to the fact that leakage current of insulation can be from many aspects such as conductive leakage, capacitive leakage, and surface leakage, one or more tests may be required to understand the total aspect of the insulation.
In some cases, external connections are required through resistors or other components for proper testing. But for general insulation resistance, connection between any two leads or from any lead to ground is all you need to do.
Many manufacturers will provide a "rule of thumb" index for allowable leakeage current on typical electrical systems and motor applications.
Ed MacLaren
Senior Member
Re: How do you Mega test wires?
If you are referring to a megger (megohmmeter) test, it is normally used to test the integrity of conductor insulation.
Depending on the type of fault suspected, you could use any of the configurations that you described (Line/Line Line/neutral Line/Ground).
Line-to-ground faults are the most common. A Line-Line or Line-Neutral fault would involve insulation damage on two or more conductors at the same point.
Make sure that the conductor under test is open (disconnected) at both ends. Remember, it is the insulation that you are testing.
Ed
If you are referring to a megger (megohmmeter) test, it is normally used to test the integrity of conductor insulation.
Depending on the type of fault suspected, you could use any of the configurations that you described (Line/Line Line/neutral Line/Ground).
Line-to-ground faults are the most common. A Line-Line or Line-Neutral fault would involve insulation damage on two or more conductors at the same point.
Make sure that the conductor under test is open (disconnected) at both ends. Remember, it is the insulation that you are testing.
Ed
luke warmwater
Senior Member
Re: How do you Mega test wires?
Has anyone other than myself ever held the leads and someone hit the switch?
Has anyone other than myself ever held the leads and someone hit the switch?
Re: How do you Mega test wires?
Thank you Ty for your idiotic responce. I suggest we try jolting you with 1000v. Maybe it would prevent you from making stupid post again.
Thanks to the more serious guys who have answered my question. Can you guys suggest a site that will have normal tolerances? The book with the meter has no information on this.
Thanks
Thank you Ty for your idiotic responce. I suggest we try jolting you with 1000v. Maybe it would prevent you from making stupid post again.
Thanks to the more serious guys who have answered my question. Can you guys suggest a site that will have normal tolerances? The book with the meter has no information on this.
Thanks
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: How do you Mega test wires?
We do have some humor in this forum and it helps to brighten our days.Try not to insult each other.
We do have some humor in this forum and it helps to brighten our days.Try not to insult each other.
Re: How do you Mega test wires?
I periodically have to megger heat trace systems. Might I suggest searching Google under "Heat Trace", you are sure to find manufacture specs for meggering heat trace systems for optimum op performance of the semi-conductor circuits prior to use. I hope this helps you!
Humor is often the learning curve needed to secure knowledge. All of us have very seroius matters that we must attend to. Humor can sometimes take the edge off of a very serious matter...Code Compliance!Originally posted by jimwalker:
We do have some humor in this forum and it helps to brighten our days.Try not to insult each other.
I periodically have to megger heat trace systems. Might I suggest searching Google under "Heat Trace", you are sure to find manufacture specs for meggering heat trace systems for optimum op performance of the semi-conductor circuits prior to use. I hope this helps you!
charlie k.
Senior Member
- Location
- Baltimore, Md.
Re: How do you Mega test wires?
Yes Ty, I have done this and had it done to me. Anybody remember hands across America? The guys at work were daring me to do it.
As for Big John you did mean meggar instead of mega didn't you.
Yes Ty, I have done this and had it done to me. Anybody remember hands across America? The guys at work were daring me to do it.
As for Big John you did mean meggar instead of mega didn't you.
luke warmwater
Senior Member
Re: How do you Mega test wires?
Hey, BigJ,
So o ory.
I felt your question was answered, and while being humorous, I was also serious.
Hit me with insults, hit me with 1000v meg, I'm here to say that I can take it, and have.
Relax and learn something from those here with knowledge and the stupid idiots.
A 1000v meg. will throw your arms completely away from the leads and will feel like your arms weigh a thousand pounds each, all the while throbbing like the drummer of a speed metal band.
Also, drool may trickle from the corner of your mouth and froth like a rabid dog. (that might not be associated with the meg., more testing would have to be done for a complete analysis)
I was 18 when this happened to me, and I'll never forget it. My boss asked me if I had ever used one, or knew how to operate it. Now I know.
Hey, BigJ,
So o ory.
I felt your question was answered, and while being humorous, I was also serious.
Hit me with insults, hit me with 1000v meg, I'm here to say that I can take it, and have.
Relax and learn something from those here with knowledge and the stupid idiots.
A 1000v meg. will throw your arms completely away from the leads and will feel like your arms weigh a thousand pounds each, all the while throbbing like the drummer of a speed metal band.
Also, drool may trickle from the corner of your mouth and froth like a rabid dog. (that might not be associated with the meg., more testing would have to be done for a complete analysis)
I was 18 when this happened to me, and I'll never forget it. My boss asked me if I had ever used one, or knew how to operate it.
Now I know.Re: How do you Mega test wires?
Didn't mean to insult anyone. Sorry for the comment. Over the years I have experienced different opinions in my area of how the test should be performed.
Example is that if you test from line/ground you are only dealing with one insulation factor. If you do Line/Line testing you have both insulated wires to consider. this is a very important test and I just wanted some serious opinions on the correct test proceedures. Im dealing with a 3 phase circuit with a ground. When the load is placed on the Breaker, the wire pings in the conduit. I do not think there is a problem with the wire but rather the breaker. When ever the load is applied the lighing thru out the building blinks. It only happens when this load is applied. They want to meg to the wires to see if they are any good. Both ends of the circuit are in good condition with no burning at the terminals. Any suggestions on how to test would be appriciated to back up what Im doing.
Im confident of my procedures a/b b/c a/c then each to ground. Record the readings then let the engineers take over from there.
Didn't mean to insult anyone. Sorry for the comment. Over the years I have experienced different opinions in my area of how the test should be performed.
Example is that if you test from line/ground you are only dealing with one insulation factor. If you do Line/Line testing you have both insulated wires to consider. this is a very important test and I just wanted some serious opinions on the correct test proceedures. Im dealing with a 3 phase circuit with a ground. When the load is placed on the Breaker, the wire pings in the conduit. I do not think there is a problem with the wire but rather the breaker. When ever the load is applied the lighing thru out the building blinks. It only happens when this load is applied. They want to meg to the wires to see if they are any good. Both ends of the circuit are in good condition with no burning at the terminals. Any suggestions on how to test would be appriciated to back up what Im doing.
Im confident of my procedures a/b b/c a/c then each to ground. Record the readings then let the engineers take over from there.
caosesvida
Senior Member
Re: How do you Mega test wires?
I use the megger for motor insulation, when I first got it I had a very difficult time finding out how to use it properly. I called the manufacturer and even motor companies. They were very vauge about how to do it. Some companies even said that they don't take megger readings for motor seriously. Over the years I have found out what most people do. I guess some things just take time. Back then there were no good forums like this , and I don't mean "no good" as in you "no good ***)
I use the megger for motor insulation, when I first got it I had a very difficult time finding out how to use it properly. I called the manufacturer and even motor companies. They were very vauge about how to do it. Some companies even said that they don't take megger readings for motor seriously. Over the years I have found out what most people do. I guess some things just take time. Back then there were no good forums like this , and I don't mean "no good" as in you "no good ***)
friebel
Senior Member
- Location
- Pennsville, N.J.
Re: How do you Mega test wires?
To: Caoseivda, A very good contact for megger information is the AVO Company. It used to be the Biddle Megger Company. You can reach them on the internet, www.avoint.com The person that I contacted was a Jeff Jowett of AVO. His phone number is 215-283-2291.
It has been a couple of years since I have talked to Jeff, and I hope that he is still with AVO. If not there will be someone that you can speak to.
The AVO Company has a couple of excellent booklets that they have always supplied to me, free of charge.
One is called "A Stitch in Time" The Complete Guide to Electrical Insulation Testing, featuring Megger Insulation Testers.
If you do contact them, also asked for their manual on Earth Resistance Testing for the practical man. It is called "Getting Down To Earth". They are excellent reading.
To: Caoseivda, A very good contact for megger information is the AVO Company. It used to be the Biddle Megger Company. You can reach them on the internet, www.avoint.com The person that I contacted was a Jeff Jowett of AVO. His phone number is 215-283-2291.
It has been a couple of years since I have talked to Jeff, and I hope that he is still with AVO. If not there will be someone that you can speak to.
The AVO Company has a couple of excellent booklets that they have always supplied to me, free of charge.
One is called "A Stitch in Time" The Complete Guide to Electrical Insulation Testing, featuring Megger Insulation Testers.
If you do contact them, also asked for their manual on Earth Resistance Testing for the practical man. It is called "Getting Down To Earth". They are excellent reading.
charlie k.
Senior Member
- Location
- Baltimore, Md.
Re: How do you Mega test wires?
John, is this a feeder for an oildraulic elevator?
If so I have had a problem with this in the past. I beleive the engineer specified a capacitor bank to solve the problem.
John, is this a feeder for an oildraulic elevator?
If so I have had a problem with this in the past. I beleive the engineer specified a capacitor bank to solve the problem.
stew
Senior Member
- Location
- federal way,washington
Re: How do you Mega test wires?
big john this sounds like an electric motor load. Is it? If so then the phenomena that you describe is exactly what happens when a motor starts or a large load is brought up . The surge causes the conductors to flex within the pipe hence the ping. Have had this happen on mg welders or spot welders especially. Every time the spot welder(in this case a very large SKIAKY unit) lit up the pipe rang like a bell .
big john this sounds like an electric motor load. Is it? If so then the phenomena that you describe is exactly what happens when a motor starts or a large load is brought up . The surge causes the conductors to flex within the pipe hence the ping. Have had this happen on mg welders or spot welders especially. Every time the spot welder(in this case a very large SKIAKY unit) lit up the pipe rang like a bell .
Re: How do you Mega test wires?
Stew.. it is an elevator. How did you solve the problem with the welders? Pull new wire with a larger size? Can the motor itself have a problem tranfering it into the wires?
Thanks for everyone's input, the owner has a limited budget to fix the problem. So replacing the entire feeder system may have to be performed but not an option at this time.
Stew.. it is an elevator. How did you solve the problem with the welders? Pull new wire with a larger size? Can the motor itself have a problem tranfering it into the wires?
Thanks for everyone's input, the owner has a limited budget to fix the problem. So replacing the entire feeder system may have to be performed but not an option at this time.
stew
Senior Member
- Location
- federal way,washington
Re: How do you Mega test wires?
The problem was solved by using a larger conductor. Still a bit of a slap but not nearly as much as before.Yes in our case very time the motor started the ping occurred.
The problem was solved by using a larger conductor. Still a bit of a slap but not nearly as much as before.Yes in our case very time the motor started the ping occurred.
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