MC Sleeved in EMT

[dirkhats]

I often see MC sleeved in EMT above the panelboard. Sometimes going down a wall to a surface receptacle. Almost always without any fitting between the MC & EMT. IThe MC looses its jacket someware inside of the EMT before it reaches the box. This seems to be a violation, yet I have seen this in several sites by different contractors. Am I missing something in the NEC which will permit this type of an install.

 

[Dennis Alwon]

Article 330.10 allows mc to be installed in any raceway. I don't see an issue as long as the jacket is bonded at least on one end.

 

[goldstar]

If the EMT is properly connected to a JB with an EMT fitting, that length of EMT has to have a mechanical connection to the MC usually by using a "from-to" type connector like this one :

http://www.bptfittings.com/Catalog/CatalogFamily.aspx?CategoryId=35&FamilyId=344

That way the EMT becomes part of the grounding system and the MC will be properly terminated. If the EMT is used strictly as a sleeve and the MC metal jacket comes out at the box end then you'll have to use both an MC connector for the box and a from-to connector where the MC enters the EMT

 

[Dennis Alwon]

I read it as mc can be installed inside a raceway not just a sleeve. I am sure there are fittings you can install at the end of the mc to bond it to the system. Now why would anyone install mc in emt for example.

 

[dirkhats]

MC Bonded

MC Bonded

I agree the MC needs to be bonded. The emt in this case is not grounding since the MC contains an insulated green grounding conductor.What I see done is the MC enters the EMT at the top, no fitting. The EMT has a fitting at the panelboard. I don't see how a fitting can be at the MC Jacket termination in the EMT or at thte box. They claim the jacket touches the EMT in sufficent length to bond. I challenge that thought. I say the MC need a proper fitting somewhere to make the transition to the EMT or to the box according to 300.15.

 

[roger]

They claim the jacket touches the EMT in sufficent length to bond.

Using this reasoning you could pull bare EGC's in raceways and never have to connect them to anything.

Roger

 

[dirkhats]

https://www.dropbox.com/s/x8rbza9cusq22ew/0919122011.jpg
If yoiu look at the linked picture, you will see an example to which I am referring. Notice the conduit on the far right, at the top.