Disconnect and MB panel ground

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Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
There is about 3' of flex from the meter to the disconnect.

Then there is about 7' (maybe 8') of flex from the disconnect to the MB panel.

You are correct. But now I am confused. Why is there 3' of flex from the meter? I thought the meter was out on the pole. Is there a piece of flex in this run?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
It starts out saying it cannot be longer than 6' if on the outside. then,,,IMO,,,the first exception after (e) allows you to do this, if he removed the bonding bushing jumper,(discard it) and landed the EBJ in the bushing, would meet the exception and be allowed to be longer than 6 ft and be on the outside.
I don't see how the exception fits the OP's situation. I still say he has a violation of 250.102(E).
 

jjhoward

Senior Member
Location
Northern NJ
Occupation
Owner TJ Electric
Hi Dennis;
Sorry for the confusion.
Meter is on the house.
First run of flex is 3 or 4' from the back of the meter pan into the disconnect.

Then there is about 7' to 8' of flex from the disconnect to the main breaker panel.
The run to main breaker panel only has 3 conductors in it, with the ground run as a seperate conductor from disconnect to main breaker panel.

I appreciate all of your input. I expect to speak with the inspector tomorrow. I will update if I get some code references from him.
Till tomorrow.
 

hurk27

Senior Member
Wow my first thought was FMC on the outside of a building" but as I interpit 348.12(1) is it is up for interpitation:confused:

I don't get the bonding bushings when the flex cannot be used as a ground?
unprotected (SEC's) in flex between meter and disco???

this whole install sounds hack, wounder what else in this house was done this way? if it was me, I would redo this service.
 

hurk27

Senior Member
Hi Dennis;
Sorry for the confusion.
Meter is on the house.
First run of flex is 3 or 4' from the back of the meter pan into the disconnect.

Then there is about 7' to 8' of flex from the disconnect to the main breaker panel.
The run to main breaker panel only has 3 conductors in it, with the ground run as a seperate conductor from disconnect to main breaker panel.

I appreciate all of your input. I expect to speak with the inspector tomorrow. I will update if I get some code references from him.
Till tomorrow.

oh ok so the flex is inside, wow why not just a back to back?

so flex between meter and first disco only needs the 3 service conductors, as the neutral serves the grounding, after this disco, well theres a problem, as far as the bonding bushings go, well what are they bonding for? surly not the flex.
 

hurk27

Senior Member
Joe -- look at article 230.43 (15). The flex cannot be over 6'

(15) Flexible metal conduit not over 1.8 m (6 ft) long or liquidtight flexible metal conduit not over 1.8 m (6 ft) long between raceways, or between raceway and service equipment, with equipment bonding jumper routed with the flexible metal conduit or the liquidtight flexible metal conduit according to the provisions of 250.102(A), (B), (C), and (E)

Now this it totally adding to my confusion, since ahead of the service disconnect the grounded conductor serves as this bonding conductor?:confused:
 

hurk27

Senior Member
Joe -- look at article 230.43 (15). The flex cannot be over 6'
230.43(15) Flexible metal conduit not over 1.8 m (6 ft) long or liquidtight flexible metal conduit not over 1.8 m (6 ft) long between raceways, or between raceway and service equipment, with equipment bonding jumper routed with the flexible metal conduit or the liquidtight flexible metal conduit according to the provisions of 250.102(A), (B), (C), and (E)

yep and 250.102(E) clearly repeats this, so the 7' of flex with the EBJ outside of the raceway is not correct
 

kwired

Electron manager
Location
NE Nebraska
Denis,
Sounds like 240.33 is saying that the service conductors cannot be routed in the flex longer than 6'.

The conductors from the meter to the disconnect are service conductors.

Are the conductors from the disconnect to the main breaker panel service conductors or feeders?

There is about 3' of flex from the meter to the disconnect.

Then there is about 7' (maybe 8') of flex from the disconnect to the MB panel.

Hi Dennis;
Sorry for the confusion.
Meter is on the house.
First run of flex is 3 or 4' from the back of the meter pan into the disconnect.

Then there is about 7' to 8' of flex from the disconnect to the main breaker panel.
The run to main breaker panel only has 3 conductors in it, with the ground run as a seperate conductor from disconnect to main breaker panel.

I appreciate all of your input. I expect to speak with the inspector tomorrow. I will update if I get some code references from him.
Till tomorrow.

Between meter and first disconnect is service conductors. First disconnect must contain overcurrent protection or have it adjacent or it is not your service disconnect. If it is not the service disconnect then you possibly have other code issues unrelated to the flex and grounding/grounded conductors that are in question.

If the first disconnect is the service disconnect then the other flex contains feeder conductors. The feeder must have an equipment grounding conductor run with the feeder conductors. The grounding electrode conductor must also run to the first disconnect and not the breaker panel.

300.3(B) Says all conductors of a circuit including equipment grounding conductors must be run within the same raceway or cable.

300.3(B)(2) allows you to run on the outside of the raceway if it done in accordance to 250.102(E)

250.102(E) limits the length of the exterior conductor to 6 feet.

As for the grounding bushings the flex is not permitted to be an equipment grounding conductor so what good does it do to connect to them - #8 copper is not large enough equipment grounding conductor for 200 amp overcurrent device anyway.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
...

300.3(B) Says all conductors of a circuit including equipment grounding conductors must be run within the same raceway or cable.

300.3(B)(2) allows you to run on the outside of the raceway if it done in accordance to 250.102(E)

...
300.3(B)(2) allows an equipment bonding jumper to be installed outside the raceway. The conductor in question is an equipment grounding conductor and not an equipment bonding conductor. I don't see any provisions that permit this EGC to be run outside the raceway.
 

kwired

Electron manager
Location
NE Nebraska
300.3(B)(2) allows an equipment bonding jumper to be installed outside the raceway. The conductor in question is an equipment grounding conductor and not an equipment bonding conductor. I don't see any provisions that permit this EGC to be run outside the raceway.

Bonding Jumper, Equipment. The connection between two or more portions of the equipment grounding conductor.

OK, so what is the difference between an equipment grounding conductor and an equipment bonding jumper? If you run it through a raceway how is it a bonding jumper and not an equipment grounding conductor when they both appear to serve the same purpose in this case. About the only thing that comes to mind that I would call an equipment bonding jumper over calling it an equipment grounding conductor is a conductor connected to a bonding bushing, or other similar device. I dont know why I would ever have a need to install this on the outside of a raceway.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
OK, so what is the difference between an equipment grounding conductor and an equipment bonding jumper? If you run it through a raceway how is it a bonding jumper and not an equipment grounding conductor when they both appear to serve the same purpose in this case. About the only thing that comes to mind that I would call an equipment bonding jumper over calling it an equipment grounding conductor is a conductor connected to a bonding bushing, or other similar device. I dont know why I would ever have a need to install this on the outside of a raceway.
I agree that I don't see a reason to ever install an equipment bonding conductor on the outside of the raceway. Exhibit 2.46 in the handbook shows the use of an equipment bonding jumper in place of the code required EGC. I see no provision in the code that lets you use an equipment bonding jumper in place of an EGC. There are a lot of issues with the code terms in Article 250 that make the use of that article much more difficult than it should be.
 

jjhoward

Senior Member
Location
Northern NJ
Occupation
Owner TJ Electric
Thank you all for the repoonses.

I did speak with the inspector on the phone.

He did NOT specifiy any NEC code articles.

I suggested that 250.102(E) addresses this situation and that in fact the flex is longer than 6'.

We also discussed the fact that this was inspected and PASSED in Aug 2005. He double checked the records at his office and yes, it was passed in 2005.

He is discussing with the construction official and will get back to me next week.
The inspector said that maybe it will be left as it is...
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
Thank you all for the repoonses.

I did speak with the inspector on the phone.

He did NOT specifiy any NEC code articles.

I suggested that 250.102(E) addresses this situation and that in fact the flex is longer than 6'.

We also discussed the fact that this was inspected and PASSED in Aug 2005. He double checked the records at his office and yes, it was passed in 2005.

He is discussing with the construction official and will get back to me next week.
The inspector said that maybe it will be left as it is...

If he lets it go you owe him a burrito
 

kwired

Electron manager
Location
NE Nebraska
Thank you all for the repoonses.

I did speak with the inspector on the phone.

He did NOT specifiy any NEC code articles.

I suggested that 250.102(E) addresses this situation and that in fact the flex is longer than 6'.

We also discussed the fact that this was inspected and PASSED in Aug 2005. He double checked the records at his office and yes, it was passed in 2005.

He is discussing with the construction official and will get back to me next week.
The inspector said that maybe it will be left as it is...

In an ideal world you should not have to fix something existing that was not part of the scope of work you were there to do. If the inspector has an issue with something existing like that he may have authority to see that is taken care of but it should be his responsibility to inform the owner of the problem and allow the owner to decide how to deal with it, chances are they will have you fix it anyhow but it was not your job to do so until they asked you to do it.

Of course we have those who think if you were there it is now your liability even if you had nothing to do with it so you better either fix it or disable the (potential) hazard in some way. With that kind of thinking I think we should all turn the main off when we leave a job especially one where we did not install everything on the premesis just in case something should go wrong we can say we tried to eliminate any problems:roll:
 
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