Message Board Thread - "Electrical Heat Tolerances"

Back to Threads | Back to Forums

TitleByPosted On
Electrical Heat Tolerances Paulie19 11/28/2007
Does anyone know which referenced publication that I could refer to in order to identify what maximum temperatures are allowable in electrical switch and receptacle boxes for residential applications.
Thanks
Paul
 
Re:Electrical Heat Tolerances gallies 12/18/2007
Paulie19 wrote:
yone know which referenced publication that I could refer to in order to identify what maximum temperatures are allowable in electrical switch and receptacle boxes for residential applications.
Thanks
Paul
One publication would be the current National Electrical Code. Each type of wire has a maximum temperature based on it's insulation. I believe most standard homes are wired with 60C wire. Anything exceeding this technically makes the ampacity for that conductor zero. For instance you really shouldn't have outlets right over radiators as the heat from them puts the conductor insulation over the limit with no load on it.
 
Re:Electrical Heat Tolerances HITECHSOLUTIONS 12/20/2007
I'm a master electrician in Mass. The NEC will givnduce you operating temperatures in specific Ambient temperatures. Table 310.16 is based off of ambient temps of 30 degrees celsius. As an industry standard, 100amps or less you base your wire size off of the 60 degree c column. 100 amps or more 75degree c column. There is a 90 c column but this is only used for derating purposes. Most conductors used in commercial applications are THHN insulation. This is in the 90 c column. Used because of it's thinner insulation. But other wise can only be loaded to the 60 or 75 c columns. It's really confusing, and you really need to know the code book well to understand. Pretty much there is no equipment rated for 90c. It's only either 60/75 or 60 or 75. You would be safe in houses to go with operating temp to be around 60c. Hope I didn't babble to much and I made sense.
 
Re:Electrical Heat Tolerances UKIR 12/26/2007
Paulie19 wrote:
yone know which referenced publication that I could refer to in order to identify what maximum temperatures are allowable in electrical switch and receptacle boxes for residential applications.
Thanks
Paul
All electrical equipment and devices are required to be UL Listed and if you need specific information look up the UL listing. You might also check manufacturers websites they have engineering data. As far as outlet boxes if they are listed they should meet or exceed the wire rating. The NEC is a good place to start.

UKIR
 


  • Back to Threads
  • Back to Forums

     

  •   Copyright © FLIR Systems, Inc 2012