Advice please on a CU swap with an unusual Radial socket cct

[freedomrun]

TN-C-S DOMESTIC. I have been asked to replace an old domestic CU with a new CU. I have performed the IR tests and all comply, all socket outlets are on a Radial configuration with 20A protection & 30mA RCD with 2.5mm squared T&E. The circuit comprises of 4 single and 1 double Socket and Central Heating controls via a switched FCU, an unswitched FCU supplying upstairs a further (cable is 2.5 T&E) 3 double sockets and a single socket, another FCU supplying two way switching for a couple of wall lights, another FCU supplying an outside PIR Flood light and another FCU supplying an outbuilding with 1.5mm SWA cable, the outbuilding has a switched FCU supplying a bulkhead light, another FCU supplying 2 double sockets and another FCU connected to a PIR outside Flood. All the cables seem to have suitable protection and all pass IR testing, the RCD complies and although this is not how i would install a circuit...... this is what i have to work with. I have also stated to the owner that i would be happier connecting the outbuilding as a seperate sub (sub main - requires a sub board and additional cable between both CU's), he will not pay to have a new CU in the outbuilding and replace the house CU too. I may be overlooking something obvious, but is there any reason why the circuit as i have outlined is not compliant in how it is laid out, with all these FCU's everywhere - the customer only wants the CU changed and the EIC with it. Thanks in advance.

 

[JamesBrownLive]

Your description is very confusing, I'm struggling to understand how many ccts there are exactly, as you only seem to mention one 20A radial?

 

[BluSparx]

What is the potential load on the 1.5mm SWA as if the guy is going the be using any equipment from this i.e. power tools etc will this be sufficient. ALthough 1.5mm can take upto 23 Amps i personally would prefer this to have been a minimum of 2.5mm or better still 4mm feeding a seperate CU as you have stated.

What is the potential load on the full circuit at maximum as likely to cause tripping if overloaded as I'm sure your aware

 

[Guest123]

It's a 20A radial circuit, albeit massive & non standard. Nothing technically wrong with it though as overcurrent protection is afforded & additional earth fault protection also.


All you can do is advise of potential pitfalls due to excessive loading causing nuisance tripping.

 

[Des 56]

It is recomended that a 2.5mm radial should be max 50 square meter area covered,your's seem to have left that figure in the far distance

What is the Zs of that little snake at the shed

Did the guy work in the factory making FCU resent: