Topsparks,
in a domestic installation i assume Uo would be the voltage at each socket/light etc, but with or without load?
The nominal voltage is simply the voltage that you write on signs and design appliances for. In the UK it's 230V or 230/400V. It cannot be measured, but in theory it is without load on the panel (consumer unit).
open circuit voltage i assume to be the voltage without any load(not swithed on)but measured where?
If there is no load, there is no voltage drop and the voltage will be the same everywhere.
For some reason, U appears to be used for voltage and V for potential in Europe. The Americans use V for both, I think.
[This message has been edited by C-H (edited 09-26-2003).]
