32A MCB feeding 1.5mm & 2.5mm T&E cables via 30A terminal block

[Monchichak]

Quickie - Would you say this is ok?

32A MCB feeding 6mm T&E which is then connected to a 2.5mm T&E & 1.5mm T&E cable via a 30A terminal block in plastic terminal block housing buried in stud wall.
The 2.5mm feeds a 3kW immersion heater with 13A SFU at the heater end.
The 1.5mm feeds gas boiler with 13A SFU at the boiler end.

Initially I thought the 1.5mm cable should not be fed with a 32A fuse but thinking about it - fault protection is provided by the 32A MCB & overload protection is provided by the 13A SFU at the end of the circuit rather than the beginning. Just doesn't seem good practice to feed a 1.5 & 2.5mm cable from a single 6mm cable protected by 32A but is it ok?

Not ideal to have boiler & water heater fed off same supply.

Fuse in switched fused spur to water heater is on the limiter - non fused switched unit would be better?

Connection should be maintenance free.

Should the connection be rated for design current or be equal to or greater than the fuse (in this case 32A)?

Many Thanks

Chris

 

[westward10]

Not sure why you are disagreeing, Zs is measured at the furthest point at the supply terminals of the fcus.

 

[johnduffell]

Not sure why you are disagreeing, Zs is measured at the furthest point at the supply terminals of the fcus.

Yes sorry that's absolutely right but not relevant to the point, i was explaining about the"Z" at the point relevant to the adiabatic, of course you were right to correct me on my incorrect use of the term Zs. Sorry for confusing matters!
I have changed to creative as there's no button for "yes agree, but that's not the point in question"