Hmmm 10mm T&E feeding a CU?!?

[festa]

Have any of you time served Sparks ever come across this?

Went to a friends new house today and took a quick look at the system.
TNC-S from underground to a 100A main fuse
16mm tails from main fuse to an old style meter
16mm tails from meter to a wylex 100A switch isolator
From the meter left a length of 10mmT&E going back underground so i traced it to a fairly new mem split load C.U in the garage(which is a side extension to the house) so this C.U (and 10mmT&E) is approx 5 meters from the main incomer.

 

[Spark123]

Sounds like a bodge job to me, 10mm is rated at about 64A maximum (clipped direct at 30deg C), hence should not be fed directly from a 100A fuse. The DNO may also impose rules on what is connected to their cutout fuse and how long it can be. A twin and earth cable should not be run underground unless it is installed in an earthed metallic conduit, which is where it becomes easier to use SWA. Tails should also really be 25mm² for a 100A supply.

 

[RF Lighting]

It is basically a submains.

Quite common and nothing wrong with doing it like this, but the cable size and installation method is sounding a bit ropey.