Correct size MCB for ring with 2.5 t&e but 1.0mm CPC

[tdecs]

Hi All, Just joined as I have a question, which is:

What size MCB should I use when replacing a 30 Amp 3036 fuse on a ring circuit that uses the old odd sized 2.5mm t&e with 1.0mm CPC. I have been reading up on calculating the CPC from cable lengths, fault currents and all sorts and have got completly confused, so help please! many thanks, Tom

 

[PC Electrics]

This cable complies on a 32A MCB or 30A 1361 fuse, but not on a 30A 3036.

 

[NozSpark]

+1

 

[binky]

+2 With MCB on circuit, disconnection time is fast enough to prevent burn out of CPC under fault conditions. Can't remember where I read this but it's a good reason to upgrade fuseboard to consumer unit.

 

[tdecs]

Hi, Thanks for responding to my question, but how would I do the calculations to back this up please?

 

[PC Electrics]

one word: adiabatic