Cord temp rating

[wireday]

Is the ratings on SO cord just for ambient temperatures? SOOW 90c , SEOOW 105c. concerned if cord should ever touch a hot pipe or something like that, wouldnt the 105c SEOOW be better suited?

 

[xptpcrewx]

Is the ratings on SO cord just for ambient temperatures? SOOW 90c , SEOOW 105c. concerned if cord should ever touch a hot pipe or something like that, wouldnt the 105c SEOOW be better suited?

The temperature rating is the maximum allowable temperature rise above ambient. If the insulation was rated 105*C and the ambient temperature happened to also be 105*C, the conductor ampacity under that condition would be zero. Insulation should not touch a hot pipe.

 

[jim dungar]

My experience has been 'industrial' products are usually based on a temperature rise above a 40C ambient.

 

[don_resqcapt19]

The temperature rating is the maximum allowable temperature rise above ambient. If the insulation was rated 105*C and the ambient temperature happened to also be 105*C, the conductor ampacity under that condition would be zero. Insulation should not touch a hot pipe.

The 105°C is the maximum permitted temperature that is a combination of the ambient and the heat produced by the current flowing in the conductor. The first sentence seems to be saying that in a 30°C ambient, a 105°C rated conductor would be permitted to operate at 135°.

 

[xptpcrewx]

The 105°C is the maximum permitted temperature that is a combination of the ambient and the heat produced by the current flowing in the conductor. The first sentence seems to be saying that in a 30°C ambient, a 105°C rated conductor would be permitted to operate at 135°.

Yes. I could have worded that better. Not suggesting 135°C as demonstrated by the subsequent sentence.

 

[Todd0x1]

Is the ratings on SO cord just for ambient temperatures? SOOW 90c , SEOOW 105c. concerned if cord should ever touch a hot pipe or something like that, wouldnt the 105c SEOOW be better suited?

Either cord must be protected from damage by external things including hot pipes. The temp ratings just have to do with the insulation materials, CPE on the SOOW and TPE on the SEOOW, with the latter having a slightly higher permissible temperature but it doesn't really matter - 90c = 194F and 105c = 221F if your cord gets to either of those temperatures you have other problems.