On Sun, 19 Mar 2017 15:20:19 +0000, wrote:

Are you sure it is 11Kv - more likely it will be 3.3Kv.

Ah, I wasn't aware that there was an intermediate distribution
voltage
between 11kV and 240V.

Wonder if H Bloomfield did a typo and meant 33Kv which is used
frequently.

There are a few intermediate voltages but I don't think it's very
common and is probably only in places that have had a supply for
around a centuary...

Here the primary substation is fed by a 33 kV line and back up 11 kV
line.
I think the 33 kV orginates at Penrith, the 11 kV from the primary at
Little Selkeld. The 11 kV has a regulator in circuit a couple of
miles from the primary substation. Even with the regulator our
voltage wangs about all over the shop when the back up 11 kV is being
used. Rises to above 255 at night and drops to 225 ish during the
day. 240 to 245 is the normal range. It was complaining about the
over voltage that lead me to finding out the 11 kV was fed from
Little Selkeld, as they dropped a couple of hundred volts off it
there and things got better (only 253 overnight) but doing that
reduces everyone else fed from that line so it didn't stay like that.
Presumably the regulator is hitting an end stop at night...

From the primamry substation the 11 kV distribution is constructed as
a collection of half a dozen or so interconnected rings. These rings
are normally operated as spurs with an auto reclosure on each one
near the primary. Manual operated air swtches that are normally open
or normally closed enable any section of line to be isolated or fed
from either end. There are a number of spurs, some branched, that can
only be fed from one end. We are on the end of one that only feeds
us.

--
Cheers
Dave.