temputure and ampacity ratings for cloth NM cable

[Riograndeelectric]

I have a Early 1950s house where I am fixing the kitchen electrical that was Jerry rigged by the GC during the remodel

the House has 2 wire cloth romex with no ground.
some of the cable is the thick black NM and other is cloth coverd gray NM cable.

all NM cables have cloth exterior insulation with with type TW conductors.

My question is what were the Temperature rating's for the cloth NM and what were the allowable ampacitys of 14-2,12-2 & 10-2

Thanks.
Cameron

 

[fishin' electrician]

60? C column in 310.16

 

[infinity]

Just a guess but IMO this is why we have the limitations of 240.4(D).

 

[Riograndeelectric]

QUOTE=fishin' electrician;1295394]60? C column in 310.16[/QUOTE]


I understand the 60C rating for type TW wire, however I am wondering of what the temperature rating is for the old cloth covered NM. I wonder if there were temperature ratings when cloth covered NM was made.
were not most older over cuurrent devices / lugs limited to 40C rating and was due to the conductors insulation.

what I am try to determian is on an older residential dwelling unit's built in the Early 1950S if the NM cable had a 60C rating or was it 40C to correspond the temperature ratings of over current protection.


if any one has a code book from the early 1950s Can you tell me what type NM cable was rated for.
Thanks.
Cameron

 

[infinity]

QUOTE=fishin' electrician;1295394]60? C column in 310.16


I understand the 60C rating for type TW wire, however I am wondering of what the temperature rating is for the old cloth covered NM. I wonder if there were temperature ratings when cloth covered NM was made.
were not most older over cuurrent devices / lugs limited to 40C rating and was due to the conductors insulation.

what I am try to determian is on an older residential dwelling unit's built in the Early 1950S if the NM cable had a 60C rating or was it 40C to correspond the temperature ratings of over current protection.


if any one has a code book from the early 1950s Can you tell me what type NM cable was rated for.
Thanks.
Cameron

Was there ever a 40? C conductor rating? Circuit breakers are sometimes labeled 40? C because that's their calibration temperature.

 

[Riograndeelectric]

Was there ever a 40? C conductor rating? Circuit breakers are sometimes labeled 40? C because that's their calibration temperature.

I do not know if there was a 40C temp rating on wire. I was just guessing at this since I have run into old panels with 40C rating.

I question whether or not cloth NM cable was listed for 60C back in its day..

while a TW conductor not matter what the age is listed for 60C, I am hesitant on believing the old cloth covered NM was listed as 60C.

I may be wrong though


Thanks.
Cameron

 

[jumper]

I am looking in a 1951 HB and there are not any #14 conductors listed as under 15 amps, #12 at 20 amps, and #10 at 30 amps.

 

[George Stolz]

Looking at the 1918, I confirm that.

The 40 degree rating is probably the ambient temperature rating of the breakers, same as today.

 

[Riograndeelectric]

Thanks guys.
I would have thought for sure that cloth NM had lower temperature rating than the plastic TW Romex

I appreciate the input and wisdom.
Cameron