Reusing existing older 60 deg NM

[Fred B]

I have a renovation older 60's extra large ranch being done that keeps getting bigger. Homeowner now is moving and eliminating a lot of the existing lighting but all existing wiring is older NM only rated 60⁰C, even receptacles are all split and switched but are only on 14AWG, any code requirements that would dictate the re-wire to the new NM-B? Would like specific code reference to support a change as GC like usual balks at idea, the existing wiring likely may not support requirements for adding AFCI based on issues I've already found. (Whoever did original was not to careful in opening the NM sheathing, slit a lot of the internal conductors and never attempted a repair, so I question condition of the wire terminations boxes that haven't been opened.)

Also neutrals shows browning from heating on some if the lighting terminations. Common issue with older NM.

 

[Little Bill]

Only code reference would be to follow the light mfg specs, which would most likely say to use 90 deg rated wire.
There is a code reference to repair the damaged insulation on the conductors.

 

[tom baker]

*IMO, what was legally installed can remain
*14 AWG is allowed except for laundry and small appliance BC, and bathrooms
*If there is evidence of damaged insulation at lighting outlets that may be a reason to replace. This damage was from installing too large incandescent lamps in lamps. This issue has largely gone away with LEDs
*The AFCI issue is one that may drive replacement. And you may find when installing AFCIs they trip due to miswiring.
*If you have to spend a lot of time replacing and troubleshooting is may not make keeping NM worth it
* Track all your conversations and replairts
* I am not sure what the pictures are you attached but it doesn't look good

 

[Fred B]

*........
* I am not sure what the pictures are you attached but it doesn't look good

That is a large junction 14X14, connecting to contactor switch controller, inside are about 12 circuits worth of wires with a lit of them being sliced by installer stripping NM sheathing. It's a mess, also not sure of effect of mess in relationship to 300.20(A) ferrous enclosure.

 

[don_resqcapt19]

It's a mess, also not sure of effect of mess in relationship to 300.20(A) ferrous enclosure.

While there may be a code issue, it is not a real world issue at currents that would be on 15 or 20 amp circuits.

The rules for this in the Canadian Electrical Code, don't even apply unless the current exceeds 200 amps.

 

[paulengr]

http://www.dli.mn.gov/sites/default/files/pdf/eli_bulletin_history.pdf

—history of residential wiring

https://ewh.ieee.org/cmte/pses/ffat/support/RESAReport.pdf

—-project results to evaluate old wiring in houses for potential long term issues.

The above project is pretty interesting in that (no surprise) even very old crappy wiring, except BX, is pretty decent. Most of the major issues found were installation issues.