Maximum Earth fault loop impedance

How to calculate the maximum Earth fault loop impedance of a circuit. Hope this is of some use to you, thanks for watching. I go on a bit so if you want to jump ahead.... 01:04 - What is EFLI 05:24 - Calculating length 07:22 - B curve Protective devices 08:34 - Calculating maximum EFLI 09:26 - Temperature 15:30 - Is the overview ------- if you want to jump ahead, probably here 17:18 - recap and other ways of calculating