I have just been talking to the son in this thread ,
//www.diynot.com/forums/viewtopic.php?p=1803905#1803905
where
and have some more information.
The "electrician" explained to the client that it was always necessary to have a volt drop along the cable to push the electricity along the wire and using larger than calculated cable would result in a lower voltage drop along the cable.
"Qualified electrician" then said
//www.diynot.com/forums/viewtopic.php?p=1803905#1803905
where
A "qualified" electrician is refusing the client's request to wire the final ring circuits with 4mm ? ~~~~
~~~~ The electrician has calculated the voltage drop as being just less than 2% so insists 2.5mm is the correct and only cable to use.
and have some more information.
The "electrician" explained to the client that it was always necessary to have a volt drop along the cable to push the electricity along the wire and using larger than calculated cable would result in a lower voltage drop along the cable.
"Qualified electrician" then said
and when the volt drop between the ends of the cable is too low not enough electricity can flow to supply the appliances with the all power they need