This one will probably wind up a few sparks here!
I am moving the switch for my immersion heater from one side of my airing cupboard to the other. On inspection of the existing cable it turns out the immersion heater is supplied by a 4.0mm2 radial. This radial is protected by a 15A rewireable fuse at the CU.
Is there any point to this? I mean, surely 2.5mm2 would have been far more appropriate in this situation! Bigger cable can't hurt but it just seems pointless.
The real question is, though, I have had some trouble sourcing 4mm cable locally so have some coming from TLC next week. However, I would like to get the job done today if possible so was wondering if it is acceptable to have a 4mm radial feeding into a 30A JB, then a 2.5mm cable from this to the immersion switch? There is no point in me doing this job today if I have to get a fused unit to feed the 2.5mm cable, I would just wait for my order.
I suspect the answer is a resounding "NO!", but I am wondering why.
I am moving the switch for my immersion heater from one side of my airing cupboard to the other. On inspection of the existing cable it turns out the immersion heater is supplied by a 4.0mm2 radial. This radial is protected by a 15A rewireable fuse at the CU.
Is there any point to this? I mean, surely 2.5mm2 would have been far more appropriate in this situation! Bigger cable can't hurt but it just seems pointless.
The real question is, though, I have had some trouble sourcing 4mm cable locally so have some coming from TLC next week. However, I would like to get the job done today if possible so was wondering if it is acceptable to have a 4mm radial feeding into a 30A JB, then a 2.5mm cable from this to the immersion switch? There is no point in me doing this job today if I have to get a fused unit to feed the 2.5mm cable, I would just wait for my order.
I suspect the answer is a resounding "NO!", but I am wondering why.