Power coming in/isolators/meters/consumer unit ..

[ChippyJoe]

Hi all,
Been asked by a neighbour about their mains power set up, has been queried by the energy company prior to a replacement meter fit.

-The have the power coming in (to their hall cupboard) which goes through 2 sealed tag main fuses.
-from there the 2 cables (+ and -) go into the meter
-from from the meter 2 cables go to a 100A block connector ** in a metal housing
-from the block connector 2 cables go too the house wiring consumer unit
BUT ALSO
-from the block connector 2 more cables go to an old isolator switch (in the same cupboard), and thereon to their attached garage, where they feed through to a separate consumer unit to their workshop there.

The energy company rep is suggesting they have an double pole isolator switch fitted instead of the block connector ** that can disconnect power to the consumer unit if necessary, and the supply to the garage then via the main consumer unit, or again via the output of the same new isolator.
Does this all sound OK. They weren't 100% sure about the isolator advised, as he said a 4 outlet one, and to the best of my knowledge the 4 pole ones are for 3 phase or additional switching ?? I thought the simple 2 in, 2 out double pole isolators should only interrupt one feed and where it is going.
Is there a double pole isolator, with 2 cable supply input, but can split to 2 separate pairs of outlet ?
The energy rep is saying this is to be done, by a competent electrician, which is fine, but prior to the new meter fit, as they wont do that.
I wasn't sure whether one consumer unit could be supplied direct from another anyway.
I hope all this makes sense, or my confusion does ! I can draw a diagram if needed !
By the way, they will be given one of these new smart screens as part of this and I hope all the (mixed) comments on these are OK nowadays ?
Many thanks, as always

[Neelix]

Sounds like you need a local competent spark

[OnlyMe]

Draw a diagram please.

BTW It's very common to power one CU from another

[ericmark]

To split power outside the CU we use Henley blocks and all the cables likely 25 mm sq, but within the CU the MCB/RCBO reduces the fault current, so smaller cables can be used.

Best option is pictures.