Wiring to boiler from Consumer unit

[yasser]

Hi Guys, a little bit of help required. I'm trying to tidy some wiring in the loft above the kitchen. Whoever lived here years ago seemed to do all his wiring with red tape and connector blocks. For some reason (probably to get rid of all the little bits of wire) they have used 4 different pieces of 1.5mm twin and earth from the consumer unit to the boiler. There is a 6amp mcb on the CU and a 3amp fuse and the boiler and there is nothing else on the radial. The question is, I have half a reel of 1.0mm in the garage, can I replace these bits with one piece of 1.0mm or should it be 1.5mm. Thanks in advance for any replies

 

[Richard Burns]

A 1 mm² T&E cable will, so long as it is not buried in insulation and bunched with other circuits, have the current carrying capacity to be safe to use, however as you are changing the capacity of cable the full range of tests for a minor works electrical installation should be undertaken to ensure that the circuit is safe to use.

 

[yasser]

Thank you for that Richard but from what you are saying would it just be easier to change like for like and its only going to cost £20-30 with no hassle of getting it tested?

 

[Octopus]

Is my memory playing up, or do the regs not call for a minimum 1.5mm for such connections?

 

[Octopus]

Thank you for that Richard but from what you are saying would it just be easier to change like for like and its only going to cost £20-30 with no hassle of getting it tested?

So you'd change a cable and NOT test it?

 

[yasser]

So you'd change a cable and NOT test it?

as that a full range of tests of the wiring because I have changed the carrying capacity or if I'm changing like for like just test to operate as it should..... I think most people knew what was meant.

 

[telectrix]

you replace the cable in it's entirity with 1.5mm. before energising, do your dead tests ( continuity, polarity, IR ) then energise, get your Zs. complete a MWC. job's a go.

 

[Richard Burns]

Is my memory playing up, or do the regs not call for a minimum 1.5mm for such connections?

Yes, power circuits minimum csa 1.5mm² no matter what size the circuit protection, a silly change introduced in amendment 2.

 

[yasser]

thank you to all contributors.