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Paper inside Romex

roughcut's picture

Hello everybody


Once again I find myself pulling wire and wiring up lights and switches. And as I have always done in the past I strip back the plastic insulation exposing the three conductors and cut the plastic insulation off. Then I strip off the paper insulation that wraps the bare copper conductor and cut it off. My question is why do they wrap the bare copper conductor separately? Does the paper wrap serve some purpose that I have just been blowing off?


Jim 

(post #105646, reply #1 of 9)

probably allows NM to maintain it's nice flat shape, provide some protection from friction, keep the thermoplastic jacket from oozing in between the conductors as it goes thru the extruder and paper is cheaper than plastic

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(post #105646, reply #2 of 9)

So you are talking it is used in the manufacturing process and has no use to the end user?

(post #105646, reply #3 of 9)

it is just filler.

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(post #105646, reply #4 of 9)

The purpose is to keep sheating from bonding to the wires.

Work with an UF (underground feeder) and you will reconize the difference.

NM is much easier to work with.

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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
. William the Geezer, the sequel to Billy the Kid - Shoe

(post #105646, reply #5 of 9)

I always thought it was for insulative purposes

(post #105646, reply #6 of 9)

No

The same insulate system on the wire, not the cable, is what is used on individual THHN/THWN that is used in conduit.

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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
. William the Geezer, the sequel to Billy the Kid - Shoe

(post #105646, reply #7 of 9)

Oh, I thought because the wire is packed so tightly in Romex that the paper was there to insulate from heat that is generated.

(post #105646, reply #8 of 9)

It's because the paper cartel got it written into the code that way.


If your view never changes you're following the wrong leader


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Paper (post #105646, reply #9 of 9)

The paper wrapped around the bare ground is fire retardant and the paper that wraps all three conductors is just a separator and for the ease of stripping the outer jacket so it slides off.