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Andrew Mawson[_2_] Andrew Mawson[_2_] is offline
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Default How much current flows through pylons?

"NY" wrote in message
...

SNIP

How much of the route from the power station to the consumer is redundant
multi-circuit? At one point, typically, does it change over to a given
house only being fed by one set of wires, and if that line develops a fault
there is no backup circuit?

Is there a backup route as far as the final substation that transforms to
11 kV or 400V, or is it higher up the chain?

I presume for maximum redundancy they try to use feeds from different
places rather than two sets of wires carried on the same pylons, in case an
accident takes out *all* the wires (both circuits).

I'm intrigued at the way house gets its electricity supply. There is
overhead mains on wooden poles (originally four separate wires, now a
single fat cable with four wires) and our house is the middle house of two
adjacent blocks of three houses. There is a single feed from the wooden
poles to the end of one block, and then four wires running along the back
of one block, overhead across the gap to the next block and along there,
with each house taking its feed from neutral and one of the three phases -
I think no two adjacent houses are on the same phase. I suppose this is
less unsightly than every one of the six houses having its own single-phase
feed from the street poles.




They always used to rotate phases down a street, so (say) phase 1 - house
1, phase 2 - house 2, phase 3 - house 3, then phase 1 - street lighting,
phase 2 - house 4 and so on down the road to balance the load between
phases.

We have the 11 kV to 415 v transformer on our land and are the first 'drop'
of single phase at the farmhouse, but also take the three phase into the
barn at 160 amps per phase. No street lighting though round here. The 11 kV
can be fed from two points - we have an overhead HV line and an underground
HV cable, but normally only one is active.

Andrew