On Tue, 31 Aug 2010 22:25:44 +0100, Adrian C
wrote:

There I was tonight in this super newly installed electric shower (oh,
and gas - but that's for another tale) and using it for the first time.
10.5kW, 44Amps or thereabouts. Wired via an RCD and spliced into the
existing meter tails to the existing consumer unit. My thoughts are on
how great this mains pressure shower actually is.

Then the lights went out. Silence.

Great

Call for SWMBO. Nothing. She'd left the house to potter in the garden
shed. I'm wet, covered in soap suds, can't see a thing, where is the
blinkin torch...

Ah, the meter ain't displaying. We've blown the supplier main fuse. All
other fuses, trips and RCDs fine.

The guy from the emergency electrical service sorts it out, and we are
back on again. However, our supplier fuses are old - probably 50 or 60
years - and from his comments look to be wired with 30 amp fuse wire.
That said, the shower overload has taken out both the live and neutral
fuse wires. He whistles though his teeth, sez "neutral, that is weird"
and trundles off with a promise to be back tomorrow to uprate the fuses
to a more consumer friendly 100 amps.

I can't see anything strange in the neutral fuse expiring, it has been
on duty for ages - and the overload of our new shower has shown it the
cards. So why is this guy whistling through his teeth?

Is tomorrow going to be a likely sales opportunity for his company?

When I did something similar (worked on a socket while live to avoid
disturbing SWMBO while she was watching Tarnation Street) I didn't get
billed because the fuse was 60A in a 4 bed house.

Derek