Article 215.6

[Lyle A]

I am working in Afghanistan for the US Gov. providing Title 2 electrical oversight on federal projects. We have problem with a contractor fighting a code ruling on feeders having a ground.

First, the site is known as KMTC. KMTC has a power plant that generates 380v and boosts it to 11kv to distribute throughout the facility.

Second, The 17kv feeds several KIOSKS. Each kiosk consists of a primary disconnect, a transformer and a secondary distribution. The secondary is a 380/220 Y.

The feeders to buildings near the kiosks do not have grounds. The buildings have a ground grid that is attached to the MDP's in each building.This system has been in place for about 3 years. Before the 2008 code.

The question is, do the feeders need to have a ground wire according to 215.6 and 250.32(B)?

We say they do and the Contractor says they don't. We have meeting with him and the Military on this tomorrow. His plans originally didn't show a ground with feeders to the buildings fed by these kiosks.

 

[roger]

I'm not sure how 215.6 applies but, considering that these feeders were installed to a pre 2008 code, 250.32(B)(2) would allow treating these feeders as new services if there are no other grounded conductive paths that could be in parallel with the neutral.

Meaning that the neutral could be grounded at these kiosks

Roger

 

[tom baker]

Starting with the 2002 NEC, a grounded conductor (neutral) could not be regrounded if it created a parallel path for current flow from a seperate building.
The 2008 NEC no longer allows regrounding the neutral.
This is for feeders to seperate buildings.
Regrounding the neutral provides the fault clearing path back to the source and the ground grid does not.
You must provide the path back to the source via the white wire, or under the current code, the green wire.
Take a look at 250.32.

 

[cripple]

Article 215.6

If the design is per 2008, and it does not show the equipment grounding conductor I would have a hard time trying to require compliance with the current code. Now if the design is per 2008 NEC the design engineer would have to address the violation.

 

[mcclary's electrical]

I am working in Afghanistan for the US Gov. providing Title 2 electrical oversight on federal projects. We have problem with a contractor fighting a code ruling on feeders having a ground.

First, the site is known as KMTC. KMTC has a power plant that generates 380v and boosts it to 11kv to distribute throughout the facility.

Second, The 17kv feeds several KIOSKS. Each kiosk consists of a primary disconnect, a transformer and a secondary distribution. The secondary is a 380/220 Y.

The feeders to buildings near the kiosks do not have grounds. The buildings have a ground grid that is attached to the MDP's in each building.This system has been in place for about 3 years. Before the 2008 code.

The question is, do the feeders need to have a ground wire according to 215.6 and 250.32(B)?

We say they do and the Contractor says they don't. We have meeting with him and the Military on this tomorrow. His plans originally didn't show a ground with feeders to the buildings fed by these kiosks.

That the key here, Where I live we're under 05' . This type of install would be legal here, provided there are no other metallic paths between the two places. Under 08' that option goes away.