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Posted to uk.d-i-y
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Supply voltage to overhead 240V mains wiring transformer
NY wrote:
As a matter of interest, what's the typical voltage of the three wires
connected to porcelain/glass insulators, mounted on wooden poles, that
feed the transformers (often pole-mounted) that step down to 240V for
overhead wiring to houses? I can't find anything on Google, using
phrases such as "overhead power line 240V" or "low voltage overhead
power line".
I presume the 240V overhead wiring is 4-wire (ie a star with a wire at
each tip and one at the centre) to allow one of the wires to be
designated as neutral and thus able to be earthed at each house just
before the "electricity board fuse". Does this neutral wire have to be
thicker than the other three because it is carrying the return current
for all three phases, or do the three return currents usually cancel
each other out (at least for the ideal case where all three phase
currents are the same magnitude and exactly 120 degrees apart)?
https://en.wikipedia.org/wiki/Distribution_transformer
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