Firstly, snap their hand off!
With caveat that I'm never great at telling cable sizes from photos, so my impression is:
From the DNO's point of view the tail sizes (25 sq mm) are adequate for 100A as far as the isolator switch (and a bit further to where they split and change to old colours).
It's virtually certain that the loading on each board is within the capacity of the red/black 16 sq mm tails, and I think you said the garage supply will be fused at 60A so the future use with EV should be ok.
Two things bothering me a bit:
Looks like no grommet/tails gland on the Switched Fuse (presumably for garage on right) where tails enter.
As it's PME I'm particularly interested (and having difficulty) deciding what size those earthing conductors are....are they all 16mm? Looking more like 10mm to me.
Hi Tim
Thanks for your reply and keen observations.
You are correct on all counts.
As the original meter economy 7 clock was faulty my electrician (Dan) suggested getting the meter changed and ask for an isolator. It was £60 charge to me for the isolator, but Dan said it will make life much easier on bringing the rest up to spec. The meter guy also fitted new blocks to take 25mm which helps further.
Yes - the earths are undersize - so they are now due to be changed to 16mm throughout, plus upping the tails elsewhere as appropriate.
Yes - I'm frankly astounded that DNO can just change the fuse, I was expecting a couple of grand quote for upgrading their supply cable from next door's gable. I presume they have historic record of their cables. FYI the supply in is only 13.5 mm OD (just measured with vernier). Seems small for 100A ?
We are planning a new 16mm SWA to the outbuilding, plus retain the existing 10mm SWA and use that only for shed and garage (and EV point one day). So we'll have 60A capable for outbuilding, plus 40A for shed / garage.
We are assuming 40 amps for shed garage should cover a typical EV charge point.
Both SWA's will have new boxes with I think Dan said RCBOs ?
Currently I have one of those 'self fit' garden supplies that plugs in a house socket with an RCD and flex to a box outside. It used to be fine but the pond pumps throw out half of the house consumer unit when faulty (already replaced 1 pump)
So all that will get reorganized and garden stuff come off the shed supply.
Need new consumer unit in outbuilding plus new smaller units for shed and garage.
Plus change the house consumer unit for metal as it's near the stairs.
So a lot to do !
BUT - with the recent hike in electricity prices I will be looking carefully at our energy - we are using too much generally. So insulation projects plus things like change hob from ceramic to induction. Hoping long term that 100A fuse will have little to do most of the time !
Dan will be busy - hoping insulation tests on the existing house wiring goes ok.