I would appreciate any advice.
I know the 16th edition on site guide gives advice on the area a ring main may cover, the size of cable and the size of protecion device, however I am going to re-wire a house in spain and would like to perform some calculations for cable and protection device selection.
I understand that Ib<In<Iz, where Ib is the design current, In is the protection device and Iz is the cable rating, please correct me if wrong. I am assuming the design current is not the maximum current as this would be massive, do I apply some diversity factors or do I make assumptions based on what appliances will be on at any one instance.
If I wire using a ring main, I am assuming that the load is split, how can I then calculate the split currents.
Also the regulations state that a cable length of 50m is acceptable, is this to restrict the number of sockets or is this related to volt drops across the cable length.
Thanks for any advice.