An insulated wire, if I pass a current at a given voltage, what will the temperature rise be.
Below is what I think I understand so far ...
I'm assuming the insulated wire is a 5 m long single conductor in free air ambient air at 20°C, with no active cooling. A typical 20 AWG stranded wire is 0.62 mm2 CSA and has a resistance of 32.4 Ω/km.
A device draws a constant 10 amps at 12 V through the wire.
There would be a volt drop over the 5 m wire.
10 A x (5 m x 0.0324) = 1.62 V
Total power passing into the wire is P = IV 120 W and power lost in the wire is 1.62 V X 10 A = 16.2 W
This power 'loss' will try to heat the wire.
The natural cooling effect around the wire will tend to cool the wire towards ambient.
The difference between these two factors should result in the temp rise of the wire.
But how would I calculate the Temp rise in degrees C?
I am aware that the insulation has an absolute upper operational limit of 105°C.
I appreciate that the insulation will have a big effect this, are there ball park values for PVC or other ways to estimate this value?