# Should the NEC mandate insulation testing?



## Black Dog (Oct 16, 2011)

MTW said:


> Should the NEC mandate insulation/hi pot/megger testing for all new wiring regardless of occupancy type? Take the poll. :thumbsup:


Have you gone mad?:blink:


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## Chris1971 (Dec 27, 2010)

.........


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## Chris1971 (Dec 27, 2010)

MTW said:


> Should the NEC mandate insulation/hi pot/megger testing for all new wiring ? Take the poll. :thumbsup:


Why add another rule or regulation. It should be left up to the discretion of the installer or if required by the end user.


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## MTW (Aug 28, 2013)

Black Dog said:


> Have you gone mad?:blink:


Go back to shilling for Donal Trump.


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## MTW (Aug 28, 2013)

Chris1971 said:


> Why add another rule or regulation. It should be left up to the discretion of the installer or if required by the end user.


Then cast your vote. :thumbsup:


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## RIVETER (Sep 26, 2009)

MTW said:


> Should the NEC mandate insulation/hi pot/megger testing for all new wiring ? Take the poll. :thumbsup:


No. Rules only, not duplicating the manufacturers job.


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## Chris1971 (Dec 27, 2010)

MTW said:


> Then cast your vote. :thumbsup:


I voted!:thumbup:


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## telsa (May 22, 2015)

MTW said:


> Go back to shilling for Donal Trump.


You must mean STUMPING...

A shill is a fake loser// winner that enables a table con [ a 'short con' ] -- typically cards or the shell game.

A retail supporter of any campaign is stumping for that campaign... as in standing on a tree stump // soap box to proclaim his views and arguments.

The conflation of one thing for another is the curse of modern discourse.

BHO is a cardinal sinner of same with his utterances. 

He's even got prostration conflated with negotiation, a supine posture unnatural to his ego. :blink:


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## Jlarson (Jun 28, 2009)

Don't care. It's already a common spec for us.


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## RIVETER (Sep 26, 2009)

Jlarson said:


> Don't care. It's already a common spec for us.


You're saying that as a normal practice you meg out all circuits and feeders and subs before energizing...right?


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## Bad Electrician (May 20, 2014)

Why would you, it only minimizes problems and if done properly can be used to track insulation resistance over the years. I received an after hours call today, they energized a switchboard today and it blew up. They wanted to know what they should do to repair the board and how to avoid future issues.

Can your say Insulation Resistance Testing?


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## Meadow (Jan 14, 2011)

Jlarson said:


> Don't care. It's already a common spec for us.



Curious, why so?


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## Black Dog (Oct 16, 2011)

MTW said:


> Go back to shilling for Donal Trump.


Great Pete; What other choice do we have?

What will Bush do?.......Nothing, however he will be the man if trump does not last------Bush will lose and we will get whoever the democrat is, that we can bet on.

To the topic, it sounds great on paper until you put a price tag on it, who will pay? the EC's that win the bid----just like the AFCI's cost us a fortune $50 per breaker, and days of trouble shooting after, depending on how large the job is.....It will be a tough sell until something blows up!


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## RIVETER (Sep 26, 2009)

Black Dog said:


> Great Pete; :thumbsup:----just like the AFCI's cost us a fortune $50 !


Like a lot of novice electricians seem to do is to think that the material for a job is costing them. It does not matter what the cost of the material is. It is the confidence that they have in themselves that they can do the job and the customer will pay for the material.


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## Jlarson (Jun 28, 2009)

meadow said:


> Curious, why so?


Its just common practice when commissioning equipment and industrial installations.


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## triden (Jun 13, 2012)

Jlarson said:


> Its just common practice when commissioning equipment and industrial installations.


It's true. A lot of times it's part of the spec and needs to be included on your sign-off sheets.


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## chicken steve (Mar 22, 2011)

*Testing......*

*Critical operations power systems 708.6 *
NFPA 70B-2013, Recommended Practice for 
Electrical Equipment Maintenance



*Ground-fault protection 230.95(C) *
(C) Performance Testing. The ground-fault protection sys-
tem shall be performance tested when first installed on site. 
The test shall be conducted in accordance with instructions 
that shall be provided with the equipment. A written record of 
this test shall be made and shall be available to the authOlity 
having jurisdiction. 


Performance testing,Understanding NEC Art. 230.95 requirements



*Mobile homes 550. 17 *
(A) Dielectric Strength Test. The wiring of each mobile 
home shall be sUbjected to a I-minute, 900-volt, dielectric 
strength test (with all switches closed) between live parts 
(including neutral conductor) and the mobile home ground. 
Alternatively, the test shall be permitted to be performed at 
1080 volts for J second. This test shall be performed after 
branch circuits are complete and after luminaires or appli-
ances are installed. 

*Park trailers 552.60* 
(A) Circuits of 120 Volts or 120/240 Volts. Each park 
trailer designed with a 120-volt or a 120/240-volt electrical 
system shall withstand the applied potential without electri-
cal breakdown of a I-minute, 900-volt dielectric strength 
test, or a I-second, 1080-volt dielectric strength test, with 
all switches closed, between ungrounded and grounded 
conductors and the park trailer ground. During the test, all 
switches and other controls shall be in the on position.

~CS~


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## MTW (Aug 28, 2013)

So far, it's not even a close race. :thumbsup:


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## Chris1971 (Dec 27, 2010)

MTW said:


> So far, it's not even a close race. :thumbsup:


I voted. Twice!:thumbup:


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## MTW (Aug 28, 2013)

Chris1971 said:


> I voted. Twice!:thumbup:


Vote early and vote often. :thumbsup:


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## Pete m. (Nov 19, 2011)

I believe it's already summed up in 110.7:

*110.7 Wiring Integrity*. Completed wiring installations shall be free from short circuits, ground faults, or any connections to ground other than as required or permitted elsewhere in this Code.

Pete


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## Meadow (Jan 14, 2011)

Pete m. said:


> I believe it's already summed up in 110.7:
> 
> *110.7 Wiring Integrity*. Completed wiring installations shall be free from short circuits, ground faults, or any connections to ground other than as required or permitted elsewhere in this Code.
> 
> Pete



x2 :thumbsup:


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## chicken steve (Mar 22, 2011)

*uuurtrrrrrpppp....*

Imho, 
the NEC does not have to mandate what is already directly in it, or in it by proxy

~CS~


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## MTW (Aug 28, 2013)

Pete m. said:


> I believe it's already summed up in 110.7:
> 
> *110.7 Wiring Integrity*. Completed wiring installations shall be free from short circuits, ground faults, or any connections to ground other than as required or permitted elsewhere in this Code.
> 
> Pete


All of that can be verified without insulation testing.


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## Meadow (Jan 14, 2011)

MTW said:


> All of that can be verified without insulation testing.



Can you explain the procedure?


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## Chris1971 (Dec 27, 2010)

Pete m. said:


> I believe it's already summed up in 110.7:
> 
> *110.7 Wiring Integrity*. Completed wiring installations shall be free from short circuits, ground faults, or any connections to ground other than as required or permitted elsewhere in this Code.
> 
> Pete


That does not state that testing is required. It may assume that will possibly take place but, it doesn't directly state the requirement.


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## Chris1971 (Dec 27, 2010)

chicken steve said:


> Imho,
> the NEC does not have to mandate what is already directly in it, or in it by proxy
> 
> ~CS~


Talk is cheap. Show me a code requirement.


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## sbrn33 (Mar 15, 2007)

Jlarson said:


> Don't care. It's already a common spec for us.


Do a lotta houses do ya?


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## Meadow (Jan 14, 2011)

sbrn33 said:


> Do a lotta houses do ya?



Again, what Im hearing is people would rather take advantage of a loop hole in our system because its easier then take pride in their work.


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## sbrn33 (Mar 15, 2007)

meadow said:


> Again, what Im hearing is people would rather take advantage of a loop hole in our system because its easier then take pride in their work.


You are hearing but you don't listen.


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## Meadow (Jan 14, 2011)

sbrn33 said:


> You are hearing but you don't listen.



Im listening. Explain what I dont know.


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## MTW (Aug 28, 2013)

meadow said:


> Can you explain the procedure?



Yes.


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## Meadow (Jan 14, 2011)

MTW said:


> Yes.



You have the stage, mic and lime light :thumbsup:


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## sbrn33 (Mar 15, 2007)

What does not Megging have to do with pride and quality?


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## Meadow (Jan 14, 2011)

sbrn33 said:


> What does not Megging have to do with pride and quality?



It verifies the installation is to code. No different then looking at a circuit breaker's handle rating before hooking up a circuit.


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## Gqmdl0617 (Apr 4, 2012)

meadow said:


> It verifies the installation is to code. No different then looking at a circuit breaker's handle rating before hooking up a circuit.


Do you load test every breaker before install too? Most likely not. We expect the manufacturer in this day and age to do the quality control testing for us and provide a quality product. As long as the install is correct there shouldn't be an issue. 

Not to say that any manufacturer is perfect. One a many arc faults have been returned among other things.


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## Meadow (Jan 14, 2011)

Gqmdl0617 said:


> Do you load test every breaker before install too? Most likely not. We expect the manufacturer in this day and age to do the quality control testing for us and provide a quality product. As long as the install is correct there shouldn't be an issue.
> 
> Not to say that any manufacturer is perfect. One a many arc faults have been returned among other things.



The breaker is already calibrated at the factory and riveted shut. No human intervention is placed on the internal parts their after. Wire on the other hand is pulled, stapled, terminated and pushed back into boxes. Rockers and builders drive nails. 





> As long as the install is correct there shouldn't be an issue.


Question I keep asking, how do you know its correct?


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## ampman (Apr 2, 2009)

Maybe it should be a suggestion like the FPN on voltage drop


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## 480sparky (Sep 20, 2007)

Gqmdl0617 said:


> .... As long as the install is correct there shouldn't be an issue. ..........


Do you stand guard 24/7 over all your 'correct' installs until it's time to trim?


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## ponyboy (Nov 18, 2012)

ampman said:


> Maybe it should be a suggestion like the FPN on voltage drop



I think that's coming to a code section near you in the immediate future


Sent from my iPad using Tapatalk


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## don_resqcapt19 (Jul 18, 2010)

If there was going to be a rule to require testing, I would not require this test....not very helpful. Circuit impedance would be a much better test to require.


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## Meadow (Jan 14, 2011)

don_resqcapt19 said:


> If there was going to be a rule to require testing, I would not require this test....not very helpful. Circuit impedance would be a much better test to require.



If you mean earth fault loop impedance to verify a function EGC Id say you are correct imho. Pools and hot tubs would be the place to start.


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## MTW (Aug 28, 2013)

meadow said:


> Again, what Im hearing is people would rather take advantage of a loop hole in our system because its easier then take pride in their work.


There is no loophole because there is no rule that says we must megger new wiring in dwelling units. If there is no rule requiring it, then it won't be done. A simple continuity test is all that's needed to comply with 110.7. There have been no statistics and no proven need to do the type of testing that you want, so it's not in the code.


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## MTW (Aug 28, 2013)

sbrn33 said:


> What does not Megging have to do with pride and quality?


Nothing. Meadow enjoys disparaging electricians who don't do the tests that he thinks should be done. There are plenty of outstanding electricians that do high quality work that never test a single thing before they energize. I never test new wiring I do and I don't plan to start.


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## macmikeman (Jan 23, 2007)

MTW said:


> Nothing. Meadow enjoys disparaging electricians who don't do the tests that he thinks should be done. There are plenty of outstanding electricians that do high quality work that never test a single thing before they energize. I never test new wiring I do and I don't plan to start.



I test wiring for payment before I energize. I test at rough in , and again at completion. If the test shows negative on the payment, energizing does not happen.


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## Lone Crapshooter (Nov 8, 2008)

Back many years ago when my area had a legitimate electrical inspection agency on residential work they would disconnect all neutrals and ring(with a telephone and bell) all of the wiring to ground as part of the final inspection.
As it is now anyone with a masters license and can pass the inspectors test and has money for the insurance can inspect.This is not a good system at all we have now.

LC


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## Meadow (Jan 14, 2011)

MTW said:


> Nothing. Meadow enjoys disparaging electricians who don't do the tests that he thinks should be done. There are plenty of outstanding electricians that do high quality work that never test a single thing before they energize. I never test new wiring I do and I don't plan to start.



Its nice to know you cant think for yourself and have to repeat what another guy said just because he was able to memorize the entire NEC word for word but know absolutely nothing about the theory behind it.


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## MTW (Aug 28, 2013)

meadow said:


> Its nice to know you cant think for yourself and have to repeat what another guy said just because he was able to memorize the entire NEC word for word but know absolutely nothing about the theory behind it.


You constantly put electricians down. Why is that?

And who might you be referring to?


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## Meadow (Jan 14, 2011)

MTW said:


> There is no loophole because there is no rule that says we must megger new wiring in dwelling units. If there is no rule requiring it, then it won't be done. A simple continuity test is all that's needed to comply with 110.7. There have been no statistics and no proven need to do the type of testing that you want, so it's not in the code.



In your eyes. Both of us know there is no black on white rule in the NEC to test wiring and I think we have long established that. The code says wiring must comply with its rules, it just doesn't say how to confirm that. Unless you have x-ray vision there is no way to know what shape the wiring is in. 


As for statics just Google "AFCIs tripping". Half the threads confirm wiring errors or over driven nails and its not just a few stray threads. So again tell me there is no proof.


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## Meadow (Jan 14, 2011)

MTW said:


> You constantly put electricians down. Why is that?
> 
> And who might you be referring to?



You just view it as putting others down. Ive posted on forums with EEs who know more then I ever will. When they give me advice on how I could do something better I dont turn it into them having a need to put me down. I view it as 'thanks for your insite'.


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## macmikeman (Jan 23, 2007)

meadow said:


> In your eyes. Both of us know there is no black on white rule in the NEC to test wiring and I think we have long established that. The code says wiring must comply with its rules, it just doesn't say how to confirm that. Unless you have x-ray vision there is no way to know what shape the wiring is in.
> 
> 
> As for statics just Google "AFCIs tripping". Half the threads confirm wiring errors or over driven nails and its not just a few stray threads. So again tell me there is no proof.



Malarky. afci trips have been astoundingly for no good reason at all. The vast majority. By far and beyond. Diehard fans always say overdriven staples. Bullcrap.


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## don_resqcapt19 (Jul 18, 2010)

meadow said:


> If you mean earth fault loop impedance to verify a function EGC Id say you are correct imho. Pools and hot tubs would be the place to start.


Not only the function of the EGC, but of the hot and neutral also. I am not in favor of testing rules, but in my opinion, a testing rule requiring an insulation resistance test is next to worthless.


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## Meadow (Jan 14, 2011)

macmikeman said:


> Malarky. afci trips have been astoundingly for no good reason at all. The vast majority. By far and beyond. Diehard fans always say overdriven staples. Bullcrap.




True, but not all. Google it and you get a slew of threads on Mike Holt "yup, found the problem, ground was touching the neutral in receptacle box"


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## Meadow (Jan 14, 2011)

don_resqcapt19 said:


> Not only the function of the EGC, but of the hot and neutral also. I am not in favor of testing rules, but in my opinion, a testing rule requiring an insulation resistance test is next to worthless.



Just wondering, what are your reasons behind IR being worthless, and a continuity between hot and neutral?

I am not disagreeing with you, just wondering about the science behind it.


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## macmikeman (Jan 23, 2007)

meadow said:


> True, but not all. Google it and you get a slew of threads on Mike Holt "yup, found the problem, ground was touching the neutral in receptacle box"



This is ten years old news you have been reading. Are you even an electrician. Every single electrician working any where near residential permit jobs knows to ensure the ground and neutral are not going to touch or else they will be returning to the scene of the crime. And they know better than overdrive staples. Yet the stupid arc fault breakers were still tripping like crazy, even though insulation resistance testing performed showed no problems. This is because the breakers were full of crap. And now a famous brand won't false trip, but hee hee hee, giggle giggle, there is no real extra arc fault protection inside them now, they just look like an arc fault breaker with a working test button. Scam of the century. Try cutting into an energized romex with one of those ''fixed'' current afci breakers, and the shower of sparks and burn marks on your side cutters will amazingly resemble perfectly your old pairs of burned up side cutters from doing it before afci's were ever even made......


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## Meadow (Jan 14, 2011)

macmikeman said:


> This is ten years old news you have been reading. Are you even an electrician. Every single electrician working any where near residential permit jobs knows to ensure the ground and neutral are not going to touch or else they will be returning to the scene of the crime. And they know better than overdrive staples. Yet the stupid arc fault breakers were still tripping like crazy, even though insulation resistance testing performed showed no problems. This is because the breakers were full of crap. And now a famous brand won't false trip, but hee hee hee, giggle giggle, there is no real extra arc fault protection inside them now, they just look like an arc fault breaker with a working test button. Scam of the century. Try cutting into an energized romex with one of those ''fixed'' current afci breakers, and the shower of sparks and burn marks on your side cutters will amazingly resemble perfectly your old pairs of burned up side cutters from doing it before afci's were ever even made......



Of course, it was GFP that made electricians think twice and those threads no matter how old proved before AFCIs were introduced electricians were leaving behind code violations. 

The rest of the trips come from NRTL listed appliances simply because AFCI breakers can not tell current signatures apart be it violent arc or a cell phone charger plugged in. 

Had GFP been introduced instead of AFCI we might not have the same amount of tripping threads, but you bet we would still have seen those where errors were being left behind. 

Without a doubt if this conversation took place in the 90s and I said "I think the NEC should mandate GFP for 120 volt circuits since some electricians are leaving behind sloppy work" Id be met with the same opposition "you are clueless, no one is leaving behind any sloppy work. Show me the tripping circuit breakers"


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## chicken steve (Mar 22, 2011)

A real world example is a heavy up, more than 6' from the original panel location aka>210.12(b) with wiring of questionable vintage

Yes ,one can ring N to G , H to N ,H to G _(with mbj and main disconnected)_ , but your only getting part of the pix.

30 millions of an amp doesn't ask much to appear an intermittent illogical problem .....

~CS~


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## Barjack (Mar 28, 2010)

This thread reminds me of the government required licensing one.

Simply mandating it doesn't guarantee anything. If I can screw up wiring I can certainly screw up a megger test.

I think it should be up to the individual electrician, and his best judgement. If I add a receptacle to an existing circuit in a house for a TV, I would say meggering is not necessary. Commissioning a motor in a chemical plant? Probably a good idea.


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## Chris1971 (Dec 27, 2010)

chicken steve said:


> A real world example is a heavy up, more than 6' from the original panel location aka>210.12(b) with wiring of questionable vintage
> 
> Yes ,one can ring N to G , H to N ,H to G _(with mbj and main disconnected)_ , but your only getting part of the pix.
> 
> ...


How does 210.12(b) relate to the OP question?


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## readydave8 (Sep 20, 2009)

MTW said:


> Should the NEC mandate insulation/hi pot/megger testing for all new wiring ? Take the poll. :thumbsup:


no no no no no no no no no no no no no no no no no no no no no no no no no

:no::no::no::no::no::no::no:


NO


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## MTW (Aug 28, 2013)

Barjack said:


> This thread reminds me of the government required licensing one.
> 
> Simply mandating it doesn't guarantee anything. If I can screw up wiring I can certainly screw up a megger test.
> 
> I think it should be up to the individual electrician, and his best judgement. If I add a receptacle to an existing circuit in a house for a TV, I would say meggering is not necessary. Commissioning a motor in a chemical plant? Probably a good idea.


Great post. :thumbsup: A blanket testing rule would require a test and certification for a simple circuit extension. How many people are going to do that? Probably about the same number that will AFCI protect that circuit extension. :whistling2:


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## Meadow (Jan 14, 2011)

The way I see it is if apprentices are taught testing as a way to double check their work it will become a habit with most carrying it out to verify themselves.


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## pete87 (Oct 22, 2012)

MTW said:


> Great post. :thumbsup: A blanket testing rule would require a test and certification for a simple circuit extension. How many people are going to do that? Probably about the same number that will AFCI protect that circuit extension. :whistling2:






MTW ... If you megged a AFCI circuit with the AFCI's in the circuit ...

Do you think that the AFCI's will fail ON ?

Might fix future problems ?




Pete


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## don_resqcapt19 (Jul 18, 2010)

meadow said:


> Just wondering, what are your reasons behind IR being worthless, and a continuity between hot and neutral?
> 
> I am not disagreeing with you, just wondering about the science behind it.


Because you can have huge chunks of insulation missing and the insulation test can still read infinity.

You could test between hot an neutral with an insulation tester as long as you have no installed or connected loads...that could give you some meaningful information.


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## Meadow (Jan 14, 2011)

So its better to meg line to neutral rather then line to ground?


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## Big John (May 23, 2010)

don_resqcapt19 said:


> Because you can have huge chunks of insulation missing and the insulation test can still read infinity....


 Agreed, but we know that the most likely short-circuit is a ground-fault. Just because a megger can't see all of them doesn't mean that test has no value.

Any proper megger would include all L-G, L-N, and N-G tests.


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## Bad Electrician (May 20, 2014)

Big John said:


> Agreed, but we know that the most likely short-circuit is a ground-fault. Just because a megger can't see all of them doesn't mean that test has no value.
> 
> Any proper megger would include all L-G, L-N, and N-G tests.


There will always be exceptions to what you can find with testing, but with proper testing you can minimize possibilities of having faults.

When I rebuild a service after a blow up or modification I do not have to hide and use a rope or stick to energize the service. I test and with confidence know the work I have completed is safe to energize.


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## chicken steve (Mar 22, 2011)

*To Meg, or not to Meg, that is the question:
Whether 'tis Nobler in the mind to suffer
The Stings and Owies of outrageous AIC ,
Or to make tests against a sea of troubles,
And by uploading them, not die, nor sleep
No more; and by a sleep, to say we end
The Headaches, and the thousand ampere shocks*

~C(w/apologies to Billy S)S~


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## MTW (Aug 28, 2013)

Bad Electrician said:


> There will always be exceptions to what you can find with testing, but with proper testing you can minimize possibilities of having faults.
> 
> When I rebuild a service after a blow up or modification I do not have to hide and use a rope or stick to energize the service. I test and with confidence know the work I have completed is safe to energize.


There's also a world of difference between large, high amperage gear and a 20 amp branch circuit.


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## chicken steve (Mar 22, 2011)

Well yes MTW, as far as the _hazard_

yet the_ theory _remains the same...

~CS~


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## Meadow (Jan 14, 2011)

Ok, burning question. How would something like this be detected if a rocker drove a nail?

http://www.mikeholt.com/htmlnews/grounding/un250-66.jpg


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## macmikeman (Jan 23, 2007)

meadow said:


> The way I see it is if apprentices are taught testing as a way to double check their work it will become a habit with most carrying it out to verify themselves.



When I was in vocational training school I was taught the usage of an insulation tester, and we were given much hands on training for the same on circuits either on a test bench or at the school buildings itself. As I recall you did not attend apprenticeship training right? Correct me if I am wrong, but did I not read how you dropped out of that or skipped it all?

Perhaps if you finished apprentice training you would not be carrying such a hard on for it now that you have become familiar with the usage . 

Me, I meg test everything commercial, almost no residential, until problems turn up, and when they do turn up, 99 times out of a hundred it is because somebody put a nail gun into the hands of a carpentry enthusiast.


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## Meadow (Jan 14, 2011)

macmikeman said:


> When I was in vocational training school I was taught the usage of an insulation tester, and we were given much hands on training for the same on circuits either on a test bench or at the school buildings itself. As I recall you did not attend apprenticeship training right? Correct me if I am wrong, but did I not read how you dropped out of that or skipped it all?
> 
> Perhaps if you finished apprentice training you would not be carrying such a hard on for it now that you have become familiar with the usage .



Ok, first I dont know why you need to mix rumors about me started by MTW just because he doesnt like what I am saying. 

Second I take it you know next to nothing about electrical engineering or advanced electrical theory?

Third you are telling me if I personally knew extra time and effort was involved in testing circuits Id say "screw it, to much effort, I am lazy" 



> Me, I meg test everything commercial, almost no residential, until problems turn up, and when they do turn up, 99 times out of a hundred it is because somebody put a nail gun into the hands of a carpentry enthusiast.


And right there you just admitted why its important to test. To assume no NM will ever be hit with a nail or by another trade is detached from reality.


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## macmikeman (Jan 23, 2007)

meadow said:


> Ok, first I dont know why you need to mix rumors about me started by MTW just because he doesnt like what I am saying.
> 
> Second I take it you know next to nothing about electrical engineering or advanced electrical theory?
> 
> ...


Two things ........., I forgot more things in my time than you ever learned, and secondly when a ''carpentry enthusiast'' uses a pneumatic nailing device that is quite capable of sending a mandatory #8 gauge nail (thank you hurricane Iniki) thru 5/8'' t-111 and thru a #12 gauge nail plate , and another 1-1/4'' of stud, and then completely thru my cable, it is going to cause a big enough short circuit to trip the breaker upon energizing due to the force of the nail entering cable is like the force of a bullet entering your midsection. The hole is the least part of the damage, the internal damage is much more widespread, resulting in either a disconnection of downstream device, or trip breaker. I am going to be made aware of the fault at completion of trim out. At which point, I get another expected fat back charge payment for the repairing of the damage, and another good opportunity to publicly mock carpentry enthusiasts. (kudos to Adam Corrolla for that one..)


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## sbrn33 (Mar 15, 2007)

So if we decide to mandate testing should we mandate the tester also?


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## Meadow (Jan 14, 2011)

> uses a pneumatic nailing device that is quite capable of sending a mandatory #8 gauge nail (thank you hurricane Iniki) thru 5/8'' t-111 and thru a #12 gauge nail plate , and another 1-1/4'' of stud, and then completely thru my cable, it is going to cause a big enough short circuit to trip the breaker upon energizing


Only if the EGC is involved. If I hit NM at a far angle I could only involve the hot energizing the nail without tripping the breaker. This I know as fact, Ive done it before. 






> due to the force of the nail entering cable is like the force of a bullet entering your midsection.


Somethings bubbling up...? Odd analogy :blink: 




> The hole is the least part of the damage, the internal damage is much more widespread, resulting in either a disconnection of downstream device, or trip breaker. I am going to be made aware of the fault at completion of trim out. At which point, I get another expected fat back charge payment for the repairing of the damage, and another good opportunity to publicly mock carpentry enthusiasts. (kudos to Adam Corrolla for that one..)


If the nail has already gone through wood and the wire is on the other side the intensity goes down, especially if driven by a hammer. Ditto for an over driven staple. Screws are another beast all together. 

The point is, you can be a perfect electrician but when those guys go to hang cabinets you dont know what will happen. An energized nail or staple will not trip the breaker if the EGC is left out of it.


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## MTW (Aug 28, 2013)

sbrn33 said:


> So if we decide to mandate testing should we mandate the tester also?


Good question, that opens up another can of worms since meg testers need to be calibrated. The whole testing idea is ridiculous anyway. I just wanted to see if anyone was on board with it and so far most are not.


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## micromind (Aug 11, 2007)

Jlarson said:


> Its just common practice when commissioning equipment and industrial installations.


Especially stuff with enough energy behind it to make a big bang should it get out of control.


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## micromind (Aug 11, 2007)

I voted No mostly because these days just about any regulation will eventually be perverted into something it was never meant to be. 

If testing became mandatory, it wouldn't be long before an inspector with an oversize ego would demand the entire system including the service conductors be tested because a light bulb was replaced. 

Personally, I don't megger very many 20 amp 120 volt circuits, but I certainly do megger just about everything I can that involves 277 or 480.


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## MTW (Aug 28, 2013)

micromind said:


> I voted No mostly because these days just about any regulation will eventually be perverted into something it was never meant to be.
> 
> If testing became mandatory, it wouldn't be long before an inspector with an oversize ego would demand the entire system including the service conductors be tested because a light bulb was replaced.



Exactly. Just what we need are more inspectors (aka failed electricians) making stuff up as they go along. Not only that, it puts even more liability on the electrician and that's never a good thing.


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## RIVETER (Sep 26, 2009)

MTW said:


> Exactly. Just what we need are more inspectors (aka failed electricians) making stuff up as they go along. Not only that, it puts even more liability on the electrician and that's never a good thing.


What if Michel Tires had to blow up every tire to unspecified pressures before they installed your tires?


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## macmikeman (Jan 23, 2007)

RIVETER said:


> What if Michel Tires had to blow up every tire to unspecified pressures before they installed your tires?


Are you using that self correcting typing feature again? I turned the damn thing off cause it keeps changing NEC to NBC.


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## RIVETER (Sep 26, 2009)

macmikeman said:


> Are you using that self correcting typing feature again? I turned the damn thing off cause it keeps changing NEC to NBC.


Not sure what you are getting at but I always am okay with corrective criticism.


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## Meadow (Jan 14, 2011)

Wait...


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## guest (Feb 21, 2009)

Moved a slew of useless bickering posts to the trash bin...all you guys (you know who you are) knock it off and stay on the OP's topic.

The NEC is already a bloated bureaucratic mess and does not need to mandate insulation testing. 

That said, as other have mentioned, in residential settings, I never do and never would on new or remodel work. (Post-fire or flood damage would be a different story...)

On any commercial 277/480 or higher voltage _*branch circuits,*_ it would depend on the circumstances as to whether or not I would do insulation/megger tests before energizing...

On ANY service or switchgear other than residential 200amps or less, I would ALWAYS do a megger test before energizing.


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## chicken steve (Mar 22, 2011)

So it appears the OP poll should be amended 

Because it seems universal the better sparks meg , but do not wish the NEC to mandate it

Despite it's existence via 230.95 (C) requirement 

~CS~


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