On 23/10/2020 17:46, Roger Mills wrote:
I'm trying to ascertain the capacity of my incoming mains just in case I
acquire an electric vehicle at some time in the future (no immediate
plans) and wish to install a charge-point.

The incoming head/main fuse looks like this:
https://app.box.com/s/ql3u40otwyax33uj8mxtn55tzq4td2ky

The OD of the (painted white) cable entering from the bottom is about
14mm. I'm assuming that this is TN-C connection with a copper concentric
cable - in which case the live conductor is likely to be 25 mm^2.

But the thought occurs to me that it just could be a TN-S supply with a
split concentric cable - in which case the central conductor would only
be 16 mm^2. Is there any way of telling which it is without breaking the
seals on the head and fuse, and looking inside?

The tails from the head to the meter and thence to two consumer units
have an OD of around 11 mm - suggesting that they are 25 mm^2 - so I'm
hoping that the incomer is, too. I don't know what size the main fuse is
without breaking the seal but presumably, if it's less than 100 amps, it
could be upgraded to 100 amps as long as the incomer is 25 mm^2?


Probably a 60A fuse. Almost certainly TN-S with split concentric cable
as there is no yellow PME sticker.


Open it up and have a look. Take some photos for the wiki to add to

http://wiki.diyfaq.org.uk/index.php/Earthing_Types

and I'll send you some meter seals to make it look OK.

Not got the paper ones that say "It is an offence etc" just the strip
and lead crimps. Cig lighter fluid removes them.





--
Adam