S
Steve Mowbray
- Jan 1, 1970
- 0
Hi - I am about to replace my old power shower and discovered the following:
9.0kW (240V) shower, 6mm² wiring (run length less than 10m), 30A rewirable
fuse in consumer unit.
To my mind this should not be possible and should really require 10mm²
wiring and a 45A fuse. Just to make sure that nothing was amiss I rewired
the fuse and also tried a replacement 30A cartridge fuse - both worked fine.
Just to make things more difficult - my old style consumer unit does not
support new style 45A fuse holders. So my simple (ish) shower replacement
job has become a much bigger new consumer unit and rewire shower fitting
job..... OR am I missing something??? The supposed 9.0kW shower has worked
fine for at least 5 years (since I moved in) and probably a few more in use
at least twice a day (at a hot setting).
I can possibly accept that a _shortish_ run of 6mm² wiring might survive
working at 110% capacity for the infrequent shower use without overheating
(much) or too high a voltage drop - but I cannot see how a 37.5A rated
device does not appear to trouble the 30A rated fuse.
Can anybody help me understand.
Ta
Steve
9.0kW (240V) shower, 6mm² wiring (run length less than 10m), 30A rewirable
fuse in consumer unit.
To my mind this should not be possible and should really require 10mm²
wiring and a 45A fuse. Just to make sure that nothing was amiss I rewired
the fuse and also tried a replacement 30A cartridge fuse - both worked fine.
Just to make things more difficult - my old style consumer unit does not
support new style 45A fuse holders. So my simple (ish) shower replacement
job has become a much bigger new consumer unit and rewire shower fitting
job..... OR am I missing something??? The supposed 9.0kW shower has worked
fine for at least 5 years (since I moved in) and probably a few more in use
at least twice a day (at a hot setting).
I can possibly accept that a _shortish_ run of 6mm² wiring might survive
working at 110% capacity for the infrequent shower use without overheating
(much) or too high a voltage drop - but I cannot see how a 37.5A rated
device does not appear to trouble the 30A rated fuse.
Can anybody help me understand.
Ta
Steve