MC to PVC

[jwelectric]

In a renovation the electrical contractor used a PVC male adapter, rigid coupling, and a MC connector to install stripped out MC in PVC under a concrete slab at which point it terminated in a square metal box. The circuit from the panel to the PVC is MC cable and transitions to the PVC that is existing under the slab.

As code enforcement officials would you accept this type of installation?

 

[jar546]

Would any particular code year make a difference before I look this one up?

 

[mark handler]

I see nothing as to why you cannot intermix plastic and metal BUT the metallic conduit MUST be bonded to the equipment grounding bus of the supply.

 

[jwelectric]

Would any particular code year make a difference before I look this one up?

2011 NEC or any type of UL listing concerning the installation

 

[gfretwell]

300.10 Electrical Continuity of Metal Raceways and Enclosures.Metal raceways, cable armor, and other metal enclosures for conductors shall be metallically joined together into a continuous electrical conductor and shall be connected to all boxes, fittings, and cabinets so as to provide effective electrical continuity.

Wouldn't the piece of PVC interrupt electrical continuity?

 

[jwelectric]

Wouldn't the piece of PVC interrupt electrical continuity?

MC cable has an insulated equipment grounding conductor inside the sheath to do any bonding with. The sheath is bonded by the fitting on the panel end so I suppose it is bonded and the box that the PVC lands in is bonded with the EGC.

I do know that the threads of the fittings and the coupling are not the same so that is one problem but stripping out about 30 feet of the MC so the conductors are exposed just don’t seem right for some reason.

If I had been doing the installation I would have installed the MC into the PVC without the stripping.

 

[chris kennedy]

Would any particular code year make a difference before I look this one up?

UL listing

Fisher Island

Aside from the obvious point of this thread I would also have to question 330.10(A)(11) in an install meeting the Art 100 def of 'Location, Wet' or in a 300.5(B) application.

 

[gfretwell]

I know some inspectors read 300.10 to say a metal raceway or metal clad cable needs to be terminated at both ends with a metal enclosure. If I want to go the way of questioning stripping 30 feet of MC and putting it in RNC I would say the conductors are not properly marked for that application.

Is it dangerous? Probably not If that particular MC is wet location listed.

If I wanted to do this and be perfectly legal I would put a handy box at the transition with appropriate connectors, bond the box, splice and use THWN in the pipe.