334.15 2005 Nec

[Cavie]

Is there a code # for grounding EMT sleeves in NEC 2002? Electricians are using it to sleve around the poured top lintel in garages. They are installing plastic bushings but are not grounding the pipe. 2005 says it shall be grounded but only states "IN Unfinished Basements". I know I'm gonna here "This is not a basement". I always used PVC cause I was told too. I cannot find a referance for grounding in the 2002 code book. Any help??

 

[dingokangaroo]

are you reffering to a pass through with emt??? in the wall or exposed?? I'm not much on residential as I've done comercial/Industrial all my life but I will try to help if you give me an idea of the apllication being used.

 

[Cavie]

Down the wall from the ceiling to the coach lights outside, down the wall to the switch for the outside light. down the wall for the A/c outside. They come down the wall about 2 blocks then duck inside the wall.

 

[Cavie]

250.86 (ex 2) says "no Ground". in both 2002 and 2005. Does 250.86 (ex 2)over ride 334.15 (c) in 2005?? Why would a unfinished basement be any different tham a garage?

 

[Smart $]

Down the wall from the ceiling to the coach lights outside, down the wall to the switch for the outside light. down the wall for the A/c outside. They come down the wall about 2 blocks then duck inside the wall.

Typically, these chases continue down through the wall (I'm assuming cmu walls) then are either stubbed out with just the threads of an emt connector protruding for placing over it a KO in a metallic box, enclosure, or disconnect switch, or connected to an embedded-nearly-flush masonry box (metallic). When the box, enclosure, or disconnect switch is grounded, so is the emt chase. Actually, these are installed from the bottom up, in sections, unless you have some magical brickies down there

Is this what you mean, or are you saying they are using an emt offset only to get around the bonding beam (you called this a poured top lintel) then "fishing" NM down through walls the rest of the way?

 

[infinity]

250.86 (ex 2) says "no Ground". in both 2002 and 2005. Does 250.86 (ex 2)over ride 334.15 (c) in 2005?? Why would a unfinished basement be any different tham a garage?

A conduit running down a wall for protection in a basement is not the same as a short piece of conduit used as a sleeve emerging from poured concrete. How would you ground a short sleeve with a piece of NM running through it?

 

[Cavie]

Infinity, That is just my point. You cannot ground the emt. That is why we use pvc. The sleve is just to jump around the bonding beam and duck into the open block wall and continue down with rx inside the block to a cut in box or a disconect outside. So I guess I found my answer in 250.86 ex 2. I just don't understand the differance between an "unfinished basement and a "Garage". the Handbook showes pipe running all the way down toa box but the actual code is not very clear on this.

 

[George Stolz]

Cavie, I submitted a proposal to change 334.15(C) to return to it's 2002 language, based on 250.86 Ex.2.

It was rejected. They offered no explanation as to why unfinished basements cannot use 250.86 Ex.2.