Cloth Insulated NM

[big john]

Anybody have any recommendations (other than ripping it out) for working with cloth-sheathed NM?

Specifically, for reasons that should be obvious with "crumble wire" I'm leary about using any pressure connectors on it when entering j-boxes. Would the best practice be to put heat-shrink on the individual conductors as well as a larger piece on the part of the sheath that would make contact with the connector?

Any other tips folks have would be appreciated.
Thanks.
-John

 

[tonyi]

Re: Cloth Insulated NM

I've been putting it on AFCI's whenver I decided to keep some in place. If its the oldest 2-wire stuff, then I'll follow up the AFCI with a GFCI receptical (most basements could use more recepticals anyway!) or use one of the Cutler AF/GF combo breakers if its a 2nd floor unit with nothing but a subpanel feeder from the basement coming up.

Some ScotchCoat rubbed into the cloth to firm it up and a few wraps of tape around it coming into a j-box will help. I'v been avoiding metal clamp type Romex connectors with it and try to use something like the Arlington NM94/95 connectors, the theory being if the sheath gives up completely at some point its not going to arc against a box with a plastic connector and the AFCI will catch a hot/neutral or hot/gnd arc if the individual conductor insulations fail.

If you have to restaple any of this stuff use insulated staples! Last year I saw some of it that almost set a place on fire because a rusty staple slow motion sawed through the cloth over time...the resultant arcing vaporized ALL conductors in a 12-3 for 4" on a sill and scorched the hell out of it.

It is evil stuff. I prefer to rip it out ;->

 

[lazorko]

Re: Cloth Insulated NM

Where I must deal with crumble wire, I wrap the individual conductors with tape; starting with several wraps around the jacket (to stabilize the tape), I run a continuous wrap of tape around the conductors. If you try to wrap the conductors alone, you run the risk of insulation failure where the jacket is stripped away. And strongly recommend that the cable be replaced!! I make a note of my recommendation on the customer's invoice and note the repair as a temporary, emergency repair to be replaced as soon as practicable.