the question says to find the impedance of a Aluminum SWA taking into account the temperature change from 20C to 70C. now the change in temperature is applied only to the resistive part of the cable (x), not the reactive part (x). If you notice, the cable has a steel wire armour and with its resistive and reactive parts. the equation 70C(a+b)x0.2 is not explained in the book. I tried many combinations using the formula you provided, but I was unsuccessful. I added the resistive parts of the core and the armour, still did not get the value shown 0.0005
the question says to find the impedance of a Aluminum SWA taking into account the temperature change from 20C to 70C. now the change in temperature is applied only to the resistive part of the cable (x), not the reactive part (x). If you notice, the cable has a steel wire armour and with its resistive and reactive parts. the equation 70C(a+b)x0.2 is not explained in the book. I tried many combinations using the formula you provided, but I was unsuccessful. I added the resistive parts of the core and the armour, still did not get the value shown 0.0005
