Cable R adjustment for changing Ambient Temperatures

[MyCleveland]

Sorry everyone, just cutting back in line....

David
..............

 

[david luchini]

David
Will try and restate a few items to see if we are on the page.

Conductor Insulation Temp : whether 60, 75, etc is the temperature of the cable IF operating at its rated full ampacity.

Conductor Temp and Termination Temp : is temperature of cable based on value of ampacity on circuit.
This will = 60, 75, etc if conductor ampacity is operating at its max ampacity in tables.

I would say the conductor insulation temperature rating is the temperature that the conductor can safely operate at in the given conditions before the insulation starts to deteriorate.

Ampacity is the maximum current that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.

So a #1 awg Cu conductor, with 3 ccc's in a raceway in a 30C ambient should be able to carry 110A without exceeding 60C, 130A without exceeding 75C, and 145A without exceeding 90C.

 

[MyCleveland]

So how does this come into play when doing a SCC calc ?

When selecting your feeders for a calc you select a 60, 75, or 90C conductor insulation value and your insulation type...XHHW or other.
You also make a selection of the equipment or feeder ambient ?