MC wiring into Nonmetallic floor box

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Carl Latona

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Section 314.3 exception 1 states use of metal raceways or metal-armored cables can be used with Nonmetallic boxes where internal bonding means are provided between all entries.

Does the internal ground wire meet this requirement for MC? The metal-sheathed cable is for physical protection and not approved for bonding with fitting.

Specially want to use plastic threaded adapter for non-metallic floor box and attach PVC coated MC between the non-metallic floor boxes. They will be poured in concrete. Is internal bonding means the ground wire in the MC?
 
The metallic sheath of the MC cable needs to be bonded at both ends.

The internal ground wire in the MC cable probably insulated, and will not suffice to bond the sheath.

If you are using something such as the MC cable with a bare oversized aluminium ground conductor, that conductor is not meant to be spliced; bonding is via the sheath only using approved connectors.

-Jon
 
winnie said:
The metallic sheath of the MC cable needs to be bonded at both ends.


-Jon
Click to expand...


Are you saying that the sheath is required to be connected to the EGC within the cable at both ends?
 
infinity said:
Are you saying that the sheath is required to be connected to the EGC within the cable at both ends?
Click to expand...

Yes. I base this on 314.3 and 314.4.

If you have armored cable or metallic conduit and a metal box, you are required to bond the box to the egc, and this of necessity bonds the sheath or conduit.

If you have armored cable or a metallic conduit and a non-metallic box, the box is required to have bonding means at all threaded entries. Why require bonding means if you are not going to bond?

(Though following Charlie's rule, I don't see where it is _required_ to use this bonding means; only that the bonding means be present....)

-Jon
 
winnie said:
Yes. I base this on 314.3 and 314.4.

If you have armored cable or metallic conduit and a metal box, you are required to bond the box to the egc, and this of necessity bonds the sheath or conduit.

If you have armored cable or a metallic conduit and a non-metallic box, the box is required to have bonding means at all threaded entries. Why require bonding means if you are not going to bond?

(Though following Charlie's rule, I don't see where it is _required_ to use this bonding means; only that the bonding means be present....)

-Jon
Click to expand...
I was thinking the same way you were. I will connect all of the bond wire together and pigtail out to the 110 volt outlet. The PVC coated MC is for protection. Yes, we are using ENT & PVC but the PVC coated MC would save time and money if able to use.
 
The inspector only had a problem when the MC was run between two nonmetallic floor boxes. 314.3 exception 1 where internal bonding means are provided between all entries. I believe the ground wire inside (internal) the MC or EMT meet this requirement.
Exception 2; I believe for the threaded entries is fulfilled when bonding wire (ground) is used and not the conduit or listed fitting since it is listed only with metal. That is what will make it integral (complete)
 
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