Question on a ground wire leaving a metal box

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FREEBALL

Senior Member
Location
york pa usa
yea I have used connectors like this for along time. I also was given 3/4 and 1" connectors to attatch to rigid couplings that were connected on EMT to bond 3/0s and 4/0s after they were stripped back, exposing the bare conductor, going to a ground bar for switch gear. I asked inspector about this use he said was to bond the conduit. So I took that idea when I use nm connectors on panels. I never thought using them this way would be any problem huh. By the way wheres the plastic bushing on the conductors :lol: be safe
 

kwired

Electron manager
Location
NE Nebraska
is using a hole not provided by the manufacturer legal by NEC (if in fact this was drilled and not a knockout)? i see in that pic a small knockout behnd the conduit, ...... not used knockout, etc.

If we are not allowed to use any holes not provided by manufacturers then we can all throw away our KO punching and hole cutting equipment as we are in violation of code/listings every time we use them:(

As far as concerns of the bare conductor being pulled and it hitting the fuse holder - it can be covered, tape or a insulating sleeve would work just fine. Use of some sort of clamping means could still end up with the conductor being pulled if high enough pull force is encountered.
 

John120/240

Senior Member
Location
Olathe, Kansas
As far as concerns of the bare conductor being pulled and it hitting the fuse holder - it can be covered, tape or a insulating sleeve would work just fine. Use of some sort of clamping means could still end up with the conductor being pulled if high enough pull force is encountered.

All correct. But if a person keeps thinking about What If conditions all day How do you get any sleep ?
 

kwired

Electron manager
Location
NE Nebraska
All correct. But if a person keeps thinking about What If conditions all day How do you get any sleep ?
I agree, I have installed many just like pictured, and probably will continue to do so until I see a high number of them being pulled into the disconnect. That number AFAIK is still at zero at this point for me, outside of severe damage where more was done then just pulling the ground conductor. Broken utility poles, vehicles crashing into equipment or hitting underground lines with excavation equipment are the most common things I see that happen that cause the problems concerned here. Pulling the ground wire is usually not the only thing to be concerned with during these events.
 

meternerd

Senior Member
Location
Athol, ID
Occupation
retired water & electric utility electrician, meter/relay tech
Take a look at 352.46

I don't want to hijack the thread, but if you look at the picture of the PVC connector, you'll see that there is barely one thread left above the locknut. PVC bushing just won't grab. I've tried. 300.G.4 also says you have to have an "identified" bushing (2011 Code). I never read that before. The ones I did see installed had pulled off and were not threaded on. Maybe some brands have longer threads, but on our 2" and 3", they just won't work. Thanks for showing me where it says they're required, though.
 
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iwire

Moderator
Staff member
Location
Massachusetts
I don't want to hijack the thread, but if you look at the picture of the PVC connector, you'll see that there is barely one thread left above the locknut.

It has been pointed out to me in the past that if we stop using PVC male adapters and use PVC box adapters the problem is solved.

http://www.cantexinc.com/Products/NM_Fittings_Accessories/Box_Adapter.php

HN1H16.jpg
 

meternerd

Senior Member
Location
Athol, ID
Occupation
retired water & electric utility electrician, meter/relay tech
It has been pointed out to me in the past that if we stop using PVC male adapters and use PVC box adapters the problem is solved.

http://www.cantexinc.com/Products/NM_Fittings_Accessories/Box_Adapter.php

HN1H16.jpg

Good idea...my only concern would be cementing a female adapter on the outside per the instructions. Seems a bit time consuming. Then you still have to use a male on the end of the conduit. Makes for a pretty long fitting. I've never seen insulation damage to any size wire from the inside of a PVC male adapter. I assume it would meet the definition of "identified" in 300.4.G. I guess I don't see the advantage, but if it satisfies an inspector, why not.
 
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don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
... I've never seen insulation damage to any size wire from the inside of a PVC male adapter. ...
I have seen the insulation of the conductor cut down to bare copper by the sharp edge of a PVC male adapter, but since the adapter is not conductive there was no ground fault.
 

meternerd

Senior Member
Location
Athol, ID
Occupation
retired water & electric utility electrician, meter/relay tech
The instructions call for that? :?

"Adapter used with the hub inside a box or enclosure. The cylinder protrudes through a hole in the box wall and is solvent welded to a female fitting outside the box or enclosure."

Here's the quote from the link provided.
 

meternerd

Senior Member
Location
Athol, ID
Occupation
retired water & electric utility electrician, meter/relay tech
I have seen the insulation of the conductor cut down to bare copper by the sharp edge of a PVC male adapter, but since the adapter is not conductive there was no ground fault.

I wonder why they couldn't just mold the male adapter with a rounded edge? Probably makes too much sense....:p
 

kwired

Electron manager
Location
NE Nebraska
I wonder why they couldn't just mold the male adapter with a rounded edge? Probably makes too much sense....:p

Then they would have less sales of the bushings. Metal fittings manufacturers do have insulated throat fittings, but they often are not competing against themselves for plastic bushing sales:happyyes:
 

FionaZuppa

Senior Member
Location
AZ
Occupation
Part Time Electrician (semi retired, old) - EE retired.
If we are not allowed to use any holes not provided by manufacturers then we can all throw away our KO punching and hole cutting equipment as we are in violation of code/listings every time we use them:(

As far as concerns of the bare conductor being pulled and it hitting the fuse holder - it can be covered, tape or a insulating sleeve would work just fine. Use of some sort of clamping means could still end up with the conductor being pulled if high enough pull force is encountered.

i meant a drilled hole, not punched for use for a UL clamp or UL fitting for termination.

sleeved sounds good, where is the sleeve in pic?

any wire "secured" can still be yanked if force is high enough.... in this case it was unsecured wired, etc.
 

kwired

Electron manager
Location
NE Nebraska
i meant a drilled hole, not punched for use for a UL clamp or UL fitting for termination.

sleeved sounds good, where is the sleeve in pic?

any wire "secured" can still be yanked if force is high enough.... in this case it was unsecured wired, etc.

I have drill bits that can drill same sized holes as holes made by some of my punches - my point was if field made holes are not allowed - we may as well throw away all our hole making equipment.

there is no sleeve in the pic, a sleeve may be seen as a good design option - but is not required.

It may or may not be secured, it definitely is not secured at or within (very) close distance of the enclosure. I've seen more cases where the entire disconnect or panel was damaged by something then just the ground wire got pulled. You can't put all what if's into code, if you did we would run RMC to everything, plus put everything into concrete vaults, and even then there may still be some what if's that were not quite covered. You can design to common conditions for the location though, and accidents will still happen at times.

I have no problem with the installation as pictured, have done hundreds of similar installations, and have never lost any sleep over any of them that I am aware of.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Good idea...my only concern would be cementing a female adapter on the outside per the instructions. Seems a bit time consuming. Then you still have to use a male on the end of the conduit. Makes for a pretty long fitting. I've never seen insulation damage to any size wire from the inside of a PVC male adapter. I assume it would meet the definition of "identified" in 300.4.G. I guess I don't see the advantage, but if it satisfies an inspector, why not.

Sorry, I must have misread this. I thought you were saying you were putting all these together in series:

Box adapter/female adapter/male adapter threaded into female/pipe

...when it just requires

Box adapter/coupling/pipe.
 

meternerd

Senior Member
Location
Athol, ID
Occupation
retired water & electric utility electrician, meter/relay tech
Sorry, I must have misread this. I thought you were saying you were putting all these together in series:

Box adapter/female adapter/male adapter threaded into female/pipe

...when it just requires

Box adapter/coupling/pipe.


"Adapter used with the hub inside a box or enclosure. The cylinder protrudes through a hole in the box wall and is solvent welded to a female fitting outside the box or enclosure." That's a quote....

It doesn't say anything about a coupling. Just quoting the link. Looks like the OD of the fitting is sized the same as the conduit OD. That means you could use a coupling or the "bell" end of a conduit but that ain't what it says. Maybe it does say that somewhere else. Either way, it's a good option. I just like stirring the pot.;)
 
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