Single Non-sheathed Conductors Passing Through a Romex Connector

[AngryElectrician]

I'm hoping someone can point me to the code rule that covers my question and settle a disagreement. In the midst of building a machine control panel, a co-worker used a standard Romex or NM cable connector to hold 4, single, #12 AWM conductors to pass through the steel panel on which all of the control equipment is mounted. From there, the conductors connect to 400V (for an overseas project) for power to the unit. I have always understood this to be a code violation, but I am unable to find the rule that applies. My understanding is that such a connector should only be used with a fully sheathed cable assembly, like a standard Romex cable. Even in the case of say, installing a Romex cable into a metal box using a standard connector, a portion of the sheath must pass through to the other side of the connector to comply with code to help prevent wire abrasion. Can anyone point me to the code rule and confirm my suspicion? Thanks.

 

[packersparky]

NEC 110.3(B). The connector is not listed for use with individual conductors, only the cables specified in the listing.

 

[Andy Delle]

NEC for USA Only

NEC for USA Only

But you said this was an overseas project? The American NEC would not apply anyway in a foreign country. You need to check the codes of the locality where this will be installed. And since it sounds like this is a custom product, it may have to have local certification like our UL or ETL. It will also need a CE stamp anywhere in Europe at a minimum.

 

[Adamjamma]

I thought single conductors have to be used in a conduit from panels or outlets, wether in IEC Rules or BS standards... think it the same in Europe, because you need to protect the wires.

 

[LarryFine]

Sounds like the NM connector was being used as a chase nipple.

 

[david]

300.12 Mechanical Continuity — Raceways and Cables.
Metal or nonmetallic raceways, cable armors, and cable sheaths shall be continuous between cabinets, boxes, fittings, or other enclosures or outlets.

300.20 Induced Currents in Ferrous Metal Enclosures or Ferrous Metal Raceways.
(A) Conductors Grouped Together. Where conductors carrying alternating current are installed in ferrous metal enclosures or ferrous metal raceways, they shall be arranged so as to avoid heating the surrounding ferrous metal by induction. To accomplish this, all phase conductors and, where used, the grounded conductor and all equipment grounding conductors shall be grouped together.

(B) Individual Conductors. Where a single conductor carrying alternating current passes through metal with magnetic properties, the inductive effect shall be minimized by (1) cutting slots in the metal between the individual holes through which the individual conductors pass or (2) passing all the conductors in the circuit through an insulating wall sufficiently large for all of the conductors of the circuit.

Do not know if your looking for something like that or not

 

[kwired]

But you said this was an overseas project? The American NEC would not apply anyway in a foreign country. You need to check the codes of the locality where this will be installed. And since it sounds like this is a custom product, it may have to have local certification like our UL or ETL. It will also need a CE stamp anywhere in Europe at a minimum.

Codes don't really matter if you are manufacturing a listed product - listing standards are what matters, such standards may take codes that will apply into some consideration for certain things, especially where field installed items are to be encountered.

Sounds like the NM connector was being used as a chase nipple.

And they work great for that in a pinch.:happyyes: I would take the clamp completely off if using for that purpose though. Over tighten it and it can cause trouble, leave it loose and it could vibrate off and fall into someplace you don't want it and cause trouble.