Cable De-rating Question

davenport.neil · Dec 12, 2011

I have to install a radial final circuit for sockets.
Most of the cable will be installed method "C" but 1 section will be reference method 100 and hence needs to be 6mm for a 32 amp MCB.
Is it generally acceptable to mix cable in this way and how sghould this be recorded in the electrical Installation Cirtificates?

Guest123 · Dec 12, 2011

Can you not just wire your radial circuit completely in 6mm???

telectrix · Dec 12, 2011

i assume that your 32A radial is in 4mm. how long is the ref,100 section?

davenport.neil · Dec 12, 2011

approx 2.8 metres

davenport.neil · Dec 12, 2011

Obviously its more expensive and if not nessessary then waste of ££.
also getting 6mm into back boxes and 13 amp socket terminals is a pain.

Guest123 · Dec 12, 2011

davenport.neil said:
Obviously its more expensive and if not nessessary then waste of ££.
also getting 6mm into back boxes and 13 amp socket terminals is a pain.

Ok, next question is what type of circuit are you installing & what for???

HandySparks · Dec 12, 2011

If the ref method 100 section is in an ordinary loft and it's only 2.8m long, can you fix a piece of wood above the level of the insulation (and any that may be added) and then clip the cable to that? It'll save the cost and complication of the bigger cable and two junction boxes. A better job all round in my opinion.