On Oct 10, 2:11*pm, "Archie" wrote:
There is currently a promotion in my area for free or subsidised Cavity
Wall Insulation. I can get it installed for 90 quid. It should be a no
brainer but one problem I have is that the electric shower cable runs up
the wall cavity and insulating the cavity would mean the cable needs to
be de-rated. The shower is 9.5kW and the cable is 6mm which is just
enough with an uninsulated cavity. I hope to get away with replacing the
6mm cable with 10mm. I used the cable calculator at tlc direct but it is
flawed. e.g. for a given set of parameters and using the default 230V it
gives a higher current answer than if 240V is used in their calculator.
A shower will consume a higher current at 240v than at 230v.

When I installed the shower cable about 20 years ago I also replaced the
CU so the shower is fed from a 40A MCB on the RCD protected side of the
CU. The cable runs up the cavity into the loft, along the gable end then
over the loft insulation down a stud partition to the shower. Re-routing
the cable to not use the cavity is not something I relish. Any comments?

Archie

Its worth it. The cost of rerouting the cable is small compared to
typical savings.


NT