How does an electrician assess the size of existing conductors when he rocks up to a property to do a job?
Let's say he's adding a circuit and needs to decide whether the meter tails are 16mm^2 or 25mm^2 (or something else - imperial?). He could disconnect them and get out his callipers but that would mean popping the main fuse. Surely not for every job? Is there a trick to this?
Alex