Is this safe?

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jerrygar

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Feeding a 50 amp sub panel in a remote building, underground. My guys pulled a an uninsulated ground by mistake (along with 2 insulated #6). I did not catch it in time to change it out before inspection. The inspector said I do not have to repull the wire (which would not be easy), just disconnect the bare conductors. He said this would be OK since I am establishing a new ground at the remote building.

Jerry
 
Do you mean that they pulled an uninsulated grounded conductor and no equipment grounding conductor?
 
infinity said:
Do you mean that they pulled an uninsulated grounded conductor and no equipment grounding conductor?
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Thats is what I get from it. Why couldnt you hook up an insulated grounded conductor to the uninsulated one and pull it through?

~Matt
 
Rob,

Yes. I am going to re-pull the wire, I was just wondering about the inspectors suggested "fix" which would leave me with no grounded conductor between the buildings.
 
infinity said:
Do you mean that they pulled an uninsulated grounded conductor and no equipment grounding conductor?
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sounded like he pulled an uninsulated ground wire. I thought that the ground had to be insulated if in conduit?
 
Grounding

Grounding

At a seperate building a new grounding system must be establised regardless if an equipment grounding conductor is installed with feeders. There really is no reason to pull an EGC. If you establish a grounding system and connect the EGC you are creating 2 ground paths in violation of the NEC. I have never pulled an EGC to a seperate building. Someone told me this changes in the 2008. You must pull the EGC and not establish grounding at the seperate building. I'll need to check this out.
 
iam14sure said:
At a seperate building a new grounding system must be establised regardless if an equipment grounding conductor is installed with feeders. There really is no reason to pull an EGC. If you establish a grounding system and connect the EGC you are creating 2 ground paths in violation of the NEC. I have never pulled an EGC to a seperate building. Someone told me this changes in the 2008. You must pull the EGC and not establish grounding at the seperate building. I'll need to check this out.
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No per 08 you need to establish a new ground at the seperate building. And I'm pretty sure you need an EGC with the feeders also.
 
iam14sure said:
At a seperate building a new grounding system must be establised regardless if an equipment grounding conductor is installed with feeders. There really is no reason to pull an EGC. If you establish a grounding system and connect the EGC you are creating 2 ground paths in violation of the NEC. I have never pulled an EGC to a seperate building. Someone told me this changes in the 2008. You must pull the EGC and not establish grounding at the seperate building. I'll need to check this out.
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yeah check this previous thread out: http://forums.mikeholt.com/showthread.php?t=104204&highlight=subpanels
 
Unless your goal is increasing your post count, you can add a comment to a post you just made, especially it pertains to the same quote.
 
LarryFine said:
Unless your goal is increasing your post count, you can add a comment to a post you just made, especially it pertains to the same quote.
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I know that Larry. I've edited my posts before and I really like that feature. No my goal isn't to increase my post count. I didn't think about adding that to the previous post.

What about you? :)
 
iam14sure said:
At a seperate building a new grounding system must be establised regardless if an equipment grounding conductor is installed with feeders. There really is no reason to pull an EGC. If you establish a grounding system and connect the EGC you are creating 2 ground paths in violation of the NEC. I have never pulled an EGC to a seperate building. Someone told me this changes in the 2008. You must pull the EGC and not establish grounding at the seperate building. I'll need to check this out.
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iam14sure, ?All grounding electrodes?that are present at each building or structure served shall be bonded together, 250.50. If there is a separate building fed from one service the existing grounding system is supposed to be expanded rather than an individual grounding system installed.

One service to a complex may have many feeds downstream the grounding system includes all electrodes connected together as a ?system?.

What you need to check out is 250.32. The serving neutral really has a duel purpose in that it is the route for returning current to source but it is also the fault path to source. If the neutral is incorrectly bonded past the service disconnect a parallel current path will be created and it will be in violation, 250.24(5) & 250.142(B).

In order for a feeder at a separate building to have a correctly bonded neutral ALL the criteria of 250.32(B)(2) must be met meaning NO conductive paths exist that are also connected to the grounding system, this is to eliminate parallel neutral paths, these are items like metal water pipe, coaxial cable, phone cable? Current will travel ALL paths to source not just the path of least resistance.

If in doubt it is best practice to install the EGC when feeding separate buildings it is required in ?08? anyway.
 
steelersman said:
sounded like he pulled an uninsulated ground wire. I thought that the ground had to be insulated if in conduit?
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I don't think it matters see 250.118(1). It may just be good practice if worried about electrolysis, but I don?t know this to be required.
 
A link to some of the changes for 2008



http://ecmweb.com/mag/electric_code_changes_13/


250.32 ? BUILDINGS OR STRUCTURES SUPPLIED BY FEEDER OR BRANCH CIRCUIT
The rule that permitted the regrounding of the neutral conductor at separate buildings and structures was deleted.

(B) Equipment Grounding Conductor. To quickly clear a ground fault and remove dangerous voltage from metal parts, the building or structure disconnecting means shall be connected to the circuit equipment grounding conductor of a type described in 250.118. Where the supply circuit equipment grounding conductor is of the wire type, it shall be sized to 250.122, based on the rating of the supply circuit overcurrent device rating (click here to see Fig. 12).


http://ecmweb.com/images/711ecmCSfig12.jpg


Exception: For existing premises, when an equipment grounding conductor was not run to the building or structure disconnecting means, the building or structure disconnecting means can remain connected to the neutral conductor where there are no continuous metallic paths between buildings and structures, ground-fault protection of equipment isn't installed on the supply side of the circuit, and the neutral conductor is sized no smaller than the larger of:

The maximum unbalanced neutral load in accordance with 220.61.

The rating of the circuit overcurrent device, in accordance with 250.122.

Caution: To prevent dangerous objectionable neutral current from flowing onto metal parts [250.6(A)], the supply circuit neutral conductor is not permitted to be connected to the remote building or structure disconnecting means [250.142(B)] (click here to see Fig. 13).

Author's comment: In the 2005 NEC, 250.32(B)(2) permitted the neutral conductor to serve as the effective ground-fault current path. This rule was converted into an exception for existing premises. Using the neutral conductor to connect metal objects to the effective ground-fault current path is a dangerous practice, especially if the neutral becomes open.
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tryinghard said:
I don't think it matters see 250.118(1). It may just be good practice if worried about electrolysis, but I don?t know this to be required.
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I agree that it is not required to be insulated . Heck it could be a combination of any number of the 14 means listed
 
sounded like he pulled an uninsulated ground wire. I thought that the ground had to be insulated if in conduit?
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Try 250.118?


Edit - Uh-oh you mean there was already a page two I didn't see?
 
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steelersman said:
I know that Larry. I've edited my posts before and I really like that feature. No my goal isn't to increase my post count. I didn't think about adding that to the previous post.

What about you? :)
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Yes, I did think about adding it to the previous post. ;)
 
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