250.118 - using emt conduit as a ground

[Strathead]

Well, I will admit that I prefer a grounding conductor in EMT. I very rarely see a job that has ANY engineer's input that doesn't require a ground, and if I were an inspector, I would obviously not require ground, but I would make it more difficult for the installer by always insisting on spot checking the tightness of connectors and couplings during rough in inspections. this would include making sure a lift was available for coupling way up high. These are the ones I see as most often left loose. Find one, fail the job. While I consider myself a conscientious worker, I know that I have accidentally left couplings loose, or only tightened a compression fitting with one wrench. I understand the arguments in the other direction and I am not implying that those who take the no ground position are wrong just that I believe installations are better off with a separated grounding wire.

 

[480sparky]

Because it's cheaper. .....

Since when did EE's care about cost?

 

[Strathead]

Since when did EE's care about cost?

definitely since never, in my experience.

 

[kwired]

Well, I will admit that I prefer a grounding conductor in EMT. I very rarely see a job that has ANY engineer's input that doesn't require a ground, and if I were an inspector, I would obviously not require ground, but I would make it more difficult for the installer by always insisting on spot checking the tightness of connectors and couplings during rough in inspections. this would include making sure a lift was available for coupling way up high. These are the ones I see as most often left loose. Find one, fail the job. While I consider myself a conscientious worker, I know that I have accidentally left couplings loose, or only tightened a compression fitting with one wrench. I understand the arguments in the other direction and I am not implying that those who take the no ground position are wrong just that I believe installations are better off with a separated grounding wire.

I might be ok with that, but if I didn't use a lift at install, I am not providing you with one. Say I crawled through rafters or was harnessed and supported by rope/cable when I installed it, I will hand you the harness and say "have at it"

 

[Strathead]

I might be ok with that, but if I didn't use a lift at install, I am not providing you with one. Say I crawled through rafters or was harnessed and supported by rope/cable when I installed it, I will hand you the harness and say "have at it"

I agree, but in the scope of long term work in a jurisdiction it would end up being the path of least resistance to just put a ground in. I have rolled over to an inspector on things a lot more heinous than this just because it was going to be the best bet in the long run.

 

[jap]

it would end up being the path of least resistance to just put a ground in.

There's no way to actually prove that.

Installing a wire type EGC holds the same issues as using the EMT conduit as a fault return path.

If the wire type EGC is not installed properly, and, bonded in all of the places that is should be, it's no better than EMT installed in the same manner.

For every inspector that needs to crawl through ever conduit run that's using the conduit as the EGC only to see if all the fittings are tight , that same inspector is going to have to go back and open every box after the install is complete to see that a wire type EGC was bonded properly at each and every location.

JAP>

 

[garbo]

EMT as an EGC.

EMT as an EGC.

We use EMT as an EGC all of the time unless someone is paying for a wire type EGC in the raceway.

45 years ago we always used the EMT as an EGC. My old boss ran several hundred feet of 3/4" EMT using the EMT an EGC and quality steel fittings indoors. Less then a year later a fitting came loose and while my boss hand one hand on either conduits and pushing them together one of the 480 volt wires shorted out. He came close to be electrocuted. We investigated why the breaker did not clear this on the recently purchased used machine. Somebody had tied this circuit to a 400 amp circuit breaker . We now run copper ground wires in every conduit. Better safe then dead. I still do not use or trust the cheap die cast EMT fittings especially the junk made in India or China.

 

[Strathead]

There's no way to actually prove that.

Installing a wire type EGC holds the same issues as using the EMT conduit as a fault return path.

If the wire type EGC is not installed properly, and, bonded in all of the places that is should be, it's no better than EMT installed in the same manner.

For every inspector that needs to crawl through ever conduit run that's using the conduit as the EGC only to see if all the fittings are tight , that same inspector is going to have to go back and open every box after the install is complete to see that a wire type EGC was bonded properly at each and every location.

JAP>

No actual way to prove what? The inspector inspects what he wants to inspect within the direction of his boss (AHJ). As I stated, if I were an inspector, I would basically make it economical to install a ground wire in all conduits. Don't worry, I'm not and I never will be. I expect that irritates some who don't want to install a ground wire. That is fine with me.

I have had an inspector either require things or make things difficult many times where we just did whatever to satisfy and make life easier in the future. I am sure it is the same for you. I doubt any contractor would be able to stay in business if they made sure to only do code minimum and prove the inspector wrong at every opportunity.

 

[jap]

No actual way to prove what?

There's no way to prove that by simply installing a wire type EGC it will magically create a path of lesser resistance.

In the end, it all boils down to the caliber of the installing electrician.

The same Electrician that installs loose conduit runs, is going to be the same electrician that doesn't terminate the wire type EGC's correctly to make the scenario any better.

Yes, pipes may come apart for some unknown reason, just like wire type EGC can be pulled loose by a connection made up by a shoddy electrician.

In my career, we were always required to install a wire type EGC also, but, I can personally say, on any project I've ever been on, I could depend on either one to due their job if one or the other happened to fail.

JAP>

 

[jap]

45 years ago we always used the EMT as an EGC. My old boss ran several hundred feet of 3/4" EMT using the EMT an EGC and quality steel fittings indoors. Less then a year later a fitting came loose and while my boss hand one hand on either conduits and pushing them together one of the 480 volt wires shorted out. He came close to be electrocuted. We investigated why the breaker did not clear this on the recently purchased used machine. Somebody had tied this circuit to a 400 amp circuit breaker . We now run copper ground wires in every conduit. Better safe then dead. I still do not use or trust the cheap die cast EMT fittings especially the junk made in India or China.

There again, this near tragedy was the result of a shoddy electrician who tied what sounds like what seems to be at most a 60 amp circuit to a 400 amp Overcurrent Protection Device.

It's likely, seeing as how this was a 3/4" conduit, and, the circuit was tied to a 400 amp breaker, that a #10 wire type EGC in this scenario probably wouldn't have helped to clear the fault either.


JAP>

 

[Strathead]

There's no way to prove that by simply installing a wire type EGC it will magically create a path of lesser resistance.



JAP>

I suspected that was what you meant. That is funny. Read it again. I was using it as an idiom. As a second year Apprentice instructor I avoid ever using the term "path of least resistance" in regards to electrical work, because it is not literally correct. All available paths inversely proportional to their resistances is electrically correct.

 

[Strathead]

There again, this near tragedy was the result of a shoddy electrician who tied what sounds like what seems to be at most a 60 amp circuit to a 400 amp Overcurrent Protection Device.

It's likely, seeing as how this was a 3/4" conduit, and, the circuit was tied to a 400 amp breaker, that a #10 wire type EGC in this scenario probably wouldn't have helped to clear the fault either.


JAP>

We get it. You don't want to install ground wires in conduits. Don't. Code allows you as a minimum installation, not to install a ground wire in a conduit. It also allows you to use romex and plastic boxes in a commercial strip mall build out too. Go for it, you can have that work and I will bid on other jobs, and proudly put our company's label on the panels.

 

[jap]

We get it. You don't want to install ground wires in conduits. Don't. Code allows you as a minimum installation, not to install a ground wire in a conduit. It also allows you to use romex and plastic boxes in a commercial strip mall build out too. Go for it, you can have that work and I will bid on other jobs, and proudly put our company's label on the panels.

No you don't get it.

As I said before, We always install a wire type EGC and always have, and, I'll put my company's label up against yours any day.

In the end the return path is dependent on the path itself and how well that path was created to begin with.

JAP>

 

[jap]

Code allows you as a minimum installation, not to install a ground wire in a conduit. It also allows you to use romex and plastic boxes in a commercial strip mall build out too. Go for it, you can have that work and I will bid on other jobs, and proudly put our company's label on the panels.

Yes, code does allow you to do all of these things.

And,

Just because you don't agree with this type of install, it doesn't mean that there aren't others who can't install a perfectly professional job using those options.

JAP>

 

[kwired]

I agree, but in the scope of long term work in a jurisdiction it would end up being the path of least resistance to just put a ground in. I have rolled over to an inspector on things a lot more heinous than this just because it was going to be the best bet in the long run.

But you indicated if you were the inspector you wouldn't need to get to that up high box if I pulled an EGC in the conduit, but if I used the conduit for EGC you would want to have access to that up high box (or something to that effect). If I pulled a EGC how you know I even connected it in the up high box if you don't go up there and verify??

 

[Strathead]

Yes, code does allow you to do all of these things.

And,

Just because you don't agree with this type of install, it doesn't mean that there aren't others who can't install a perfectly professional job using those options.

JAP>

Which is said earlier. It isn't an issue of "agreeing". I know the code. I am also very aware of article 90. Code minimum is a valid acceptable standard to perform installations. Luckily we are not forced to install to minimums. I am arrogant enough to, on some level believe my ways are the best, while intelligent and self-aware enough to realize that everyone other good electrician has a different set of standards and many, probably most, including yours are actually every bit as "best" as I think mine are.

(The above is intended to be taken lightly, with a certain amount of humor, a certain amount of humility and a certain amount of self truth. Please take it that way.) After all don't you believe your ways are the best ways? Anyone who says no, I ask, 'Then why don't you do it the best way?"

 

[Strathead]

But you indicated if you were the inspector you wouldn't need to get to that up high box if I pulled an EGC in the conduit, but if I used the conduit for EGC you would want to have access to that up high box (or something to that effect). If I pulled a EGC how you know I even connected it in the up high box if you don't go up there and verify??

Nope, I didn't state, "need" from any code perspective. I was trying to convey that I would make it more difficult for you, if you chose not to install a green ground wire in your conduits. I also stated the reason. My belief that even the best of us overlook things on occasion. A fault return path is important enough to me that I would be OK with being an a$$ about that. Regarding the high up box, I am not that concerned about a single, not readily accessible box being well bonded. Again, I am not an inspector, I never will be an inspector, everyone was stating how they don't run grounds in conduits, I was presenting the other side. And for the record on a personal level, most of the electricians and contractors that I know prefer to install a ground wire in their conduits. Sort of like how we used to just drive two ground rods instead of testing to prove they had less than 25 ohms resistance.

 

[david]

Less then a year later a fitting came loose and while my boss hand one hand on either conduits and pushing them together one of the 480 volt wires shorted out. He came close to be electrocuted.

Just curious where was the short the panel side or the side the equipment ground was compromised on. I am guessing this coupling was at a 90 deg. bend, if an attempt was made to push the conduit into a coupling.

You and your boss most likely had a conversation about pinching the wire while doing it on a live circuit

 

[jap]

If I pulled a EGC how you know I even connected it in the up high box if you don't go up there and verify??

Because K-wired, he said if he ever became an inspector he would make it more economical for us all to install a wire type EGC.

Which I guess means he would pay us for the labor and material required to install one, not sure.

If I was going to pay for the wire and labor to install a wire type EGC,that I couldn't enforce to be installed, you better bet I'd be up there crawling around making sure it was installed properly also.

JAP>

 

[jap]

Just curious where was the short the panel side or the side the equipment ground was compromised on. I am guessing this coupling was at a 90 deg. bend, if an attempt was made to push the conduit into a coupling.

You and your boss most likely had a conversation about pinching the wire while doing it on a live circuit

I agree.

If the thought of possibly shorting out the wiring, while trying to push the pipe back together full of energized circuit didn't come to mind, It should have.

JAP>