neutral and grounds tied together at grounding electrode

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papa smurf

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I recently inspected a job where a 3phase main panels neutral and ground where tied together and then the grounding couductor went to the grounding electrode. The subpanel was only fed with 4 wires with no grounding conductor but they ran a grounding conductor from the subpanel to the same grounding electrode. To me its basicly the same thing as running the 5th wire from the main to the subpanel, but the difference is there meeting at the grounding electrode. Is this Leagal.
 
papa smurf said:
Is this Legal.
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Maybe.

Are the neutrals and EGCs isolated from one another in the sub-panel?

Is the feeder to the sub-panel contained in a metal raceway?

If the feeder is a raceway that meets the requirements in 250.118 then you have an EGC. If that is the case you are allowed to run additional conductors from the EGC anywhere in the building to grounding electrodes.
 
papa smurf said:
I recently inspected a job where a 3phase main panels neutral and ground where tied together and then the grounding couductor went to the grounding electrode. The subpanel was only fed with 4 wires with no grounding conductor but they ran a grounding conductor from the subpanel to the same grounding electrode. To me its basicly the same thing as running the 5th wire from the main to the subpanel, but the difference is there meeting at the grounding electrode. Is this Leagal.
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You are an inspector?
 
iwire said:
Maybe.

Are the neutrals and EGCs isolated from one another in the sub-panel?

Is the feeder to the sub-panel contained in a metal raceway?

If the feeder is a raceway that meets the requirements in 250.118 then you have an EGC. If that is the case you are allowed to run additional conductors from the EGC anywhere in the building to grounding electrodes.
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iwire, Thanks for your professional answer. Yes the neutrals and EGCs are isolated from one another in the sub-panel and the feeder is not in a metal raceway. Also thanks to the dedicated men and woman that contribute there expertise in helping the many trying to make a difference, and to those who can't act professional don't use this forum and learn some manners.

Thanks

Papa Smurf
 
papa smurf said:
I recently inspected a job where a 3phase main panels neutral and ground where tied together and then the grounding couductor went to the grounding electrode. The subpanel was only fed with 4 wires with no grounding conductor but they ran a grounding conductor from the subpanel to the same grounding electrode. To me its basicly the same thing as running the 5th wire from the main to the subpanel, but the difference is there meeting at the grounding electrode. Is this Leagal.
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In My opinion.....Not legal.

300.3(B)

steve
 
David C. Adkins said:
It's Legal !!!!
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Dave, 300.3(B)2 does not apply.

Papa smurf. What year code do you want to enforce and did you determine if there are any metallic utility paths between the service equipment and the building/s. If you want to enforce the 2008 standard, and this is a new building, have a contractor install a new feeder. Might cost more than the original install, but it would meet current code and set a example for the upcoming construction sites.

Rick
 
papa smurf said:
I recently inspected a job where a 3phase main panels neutral and ground where tied together and then the grounding couductor went to the grounding electrode. The subpanel was only fed with 4 wires with no grounding conductor but they ran a grounding conductor from the subpanel to the same grounding electrode. To me its basicly the same thing as running the 5th wire from the main to the subpanel, but the difference is there meeting at the grounding electrode. Is this Leagal.
Click to expand...



In reading this again, I have a question.
Is the wiring method from the service panel to the subpanel a metallic raceway? or is the cable method if not a raceway one of the wiring methods with the sheath acceptable as per 250.118?
 
Pierre C Belarge said:
I agree, isolate the grounded conductor as per the OP's post, and this installation is fine.
One can install as many grounding electrodes and conductors from the electrodes on premises wiring, as one wants, as long as the grounded conductor is isolate from the equipment grounding conductor and metallic parts.
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Pierre, the GEC only connects the back box to the electrode. The neutral is isolated and the raceway and conductors are without a ground path other than the commom GEC.

Rick
 
It has become more apparent from reading other posts that there is a common ground wire that is installed from the source of power to all electrical equipment throughout the facilities. This ground wire is being used for the building grounding electrode, the grounding electrode conductor, the equipment ground and the bonding jumpers at the seperately derived systems.

I would say it accomplishes it's function, but in the United States, we are required to run a seperate grounding conductor "with" our feeders individually. This helps to troubleshoot and test, makes an effective ground fault path back to the source if a feeder should get cut and keeps it simple when changing and retrofitting buildings and equipment.

The first thing i would do is check the integrity of the grounding conductor, make sure all the bonding jumpers are in the right places, and then decide if you want upgrade to a feeder with an equipment ground.

Rick
 
RUWired said:
It has become more apparent from reading other posts that there is a common ground wire that is installed from the source of power to all electrical equipment throughout the facilities. This ground wire is being used for the building grounding electrode, the grounding electrode conductor, the equipment ground and the bonding jumpers at the seperately derived systems.

I would say it accomplishes it's function, but in the United States, we are required to run a seperate grounding conductor "with" our feeders individually. This helps to troubleshoot and test, makes an effective ground fault path back to the source if a feeder should get cut and keeps it simple when changing and retrofitting buildings and equipment.

The first thing i would do is check the integrity of the grounding conductor, make sure all the bonding jumpers are in the right places, and then decide if you want upgrade to a feeder with an equipment ground.

Rick
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I agree, and I still don't think that it meets code.:smile:

steve
 
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