We have a 90 deg C. rated PEX cable copper sized 1x185mmm2. This cable is to be used in 45 deg C environment (alone in air on a cable tray). We want to use it in intermittent operation where the cable will be loaded with 600 kW for 40 seconds, then nothing for 40 seconds. Then repeat. The voltage is 1050 V DC. Lets say the cable is 45 dec C. Then full current 600kW / 1050 V is applied for 40 seconds. How can we calculate how much the temperature rise will be? What will be the cables temperature after the 40 seconds? Can we calculate how much the temperature has dropped after the 40 seconds rest period?