Is this wrong and if so why ?
MCB is 16 amp. Cable from CU is 10mm² for a run of 45 metres to a 60 amp junction box ( only size that would take the 10 mm² ). From the JB a metre of 2.5mm² goes to an FCU with 13 amp fuse. From the FCU less than a metre of 2.5mm² to feed a 13 amp unswitched socket under work top for 2.8 Kw cooker.
The JB is accessible, the FCU cannot take 10mm² The CU is labeled with 16 Amp Max over the MCB
Reason for 10 mm² is to reduced voltage drop and power wastage in the 45 metre run.
The jobsworth objector is saying that in the future some one will see 10mm² in the MCB and assume it is safe to up-grade to a 32 or 40 amp MCD leaving the 2.5mm² at the far end without safe protection.
Would he have been better to have come from the CU in 2.5mm² to a 60 amp JB and run the 20mm² from there.
MCB is 16 amp. Cable from CU is 10mm² for a run of 45 metres to a 60 amp junction box ( only size that would take the 10 mm² ). From the JB a metre of 2.5mm² goes to an FCU with 13 amp fuse. From the FCU less than a metre of 2.5mm² to feed a 13 amp unswitched socket under work top for 2.8 Kw cooker.
The JB is accessible, the FCU cannot take 10mm² The CU is labeled with 16 Amp Max over the MCB
Reason for 10 mm² is to reduced voltage drop and power wastage in the 45 metre run.
The jobsworth objector is saying that in the future some one will see 10mm² in the MCB and assume it is safe to up-grade to a 32 or 40 amp MCD leaving the 2.5mm² at the far end without safe protection.
Would he have been better to have come from the CU in 2.5mm² to a 60 amp JB and run the 20mm² from there.