OT Voltages

[D. Schouten]

Hi,

>> I have a question for some of the UK or other Europe guys.  If your service
>> is 235 only what is the relationship between each of these conductors and
>> earth.  Is one leg of your 235 considered a neutral (one leg of 120 is a
>> neutral in the US). Or, do both legs of the 235 volt supply have potential
>> above ground (earth)?
>
>And Oztrayleea.
>
>Here one leg is 240, the other is neutral. The frequency is 50Hz.
>
>The neural is earthed at one point in a domestic installation.
>
>Some houses and industrial complexes have 3 phase power, which gives 3 lines
>at 415 volts each relative to each other. Each of the 415V lines is
individually
>240 Volts above earth. An exercise for the mathematicians is to explain how
this
>can be !!


This is because the secondaries of the local grid transformer are connected in a
socalled Wye configuration with the neutral conductor connected in the star
point. The 400V voltages are present relative on the exits of this Wye (=Y),
while the line voltages of 230V are present on these exits relative to the
neutral.