Electricity LV mains distribution - questions about CONSAC cables
steve
with power cuts. It's been going on for at least 2 years, and the typical
failure results in men digging up the road and replacing joints on the LV
(230V) underground cable. The estate was built in the late seventies/early
eighties. I'm given to understand that the most likely cause is that our
underground cabling uses CONSAC cable, which I believe was thought to be a
good idea at the time, but has proved to be unreliable.
Do any of you have any information about this cable, and why it fails at the
joints? I'd be particularly interested to know if any of the failure modes
can result in customer over-voltages/power surges (anecdotal information
from another affected area suggests it can, but I'd be looking for stronger
evidence).
Alternatively, pointers to a more relevant newsgroup would be appreciated.
TIA,
Steve S
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<steve...@CutThisBitOff.blueyonder.co.uk> writes
>
>, and the typical
>failure results in men digging up the road and replacing joints on the LV
>(230V) underground cable. The estate was built in the late seventies/early
>eighties. I'm given to understand that the most likely cause is that our
>underground cabling uses CONSAC cable, which I believe was thought to be a
>good idea at the time, but has proved to be unreliable.
>
>
comments:
CONSAC LV cable was one of the two main types of aluminium core/sheath
distributor (as opposed to WAVCON) and was introduced because of the
price of copper.
It comprises three cores for the three phases, and the sheath acts as
neutral, earth conductor, and gives mechanical protection.
Because of the conductivity of aluminium, it is a larger diameter then
the copper equivalent, even though there are only three cores.
Main drawback is rather larger bending radii. Also, the dreaded PME had
to be adopted, but that's another story.
The cable itself is reliable enough.
The jointing technique was not consistent throughout the country, and
poor practice took time to correct. (This was worse where contractors
were used: their attitude was sometimes less than satisfactory!)
Because of this, you may be suffering from a greater number of outages
than should be expected.
The joints on the cables in your area can be located and remade, but at
a cost which the supply companies will not meet.
Don't suppose this helps!
--
Wilf, who remembers "PRESS PLAY ON TAPE #1"
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