On 06/09/2019 10:17, Mike Clarke wrote:
On 04/09/2019 16:41, Alan wrote:
On Wed, 04 Sep 2019 15:53:41 +0100, GB wrote:
The Eon guy came to fit the samrt metter. He put on his work gloves.
Fair enough. He put on his polycarbonate glasses. Still fair enough.

Then, he donned thick elbow length rubber gauntlets, plus a full face
polycarbonate shield. THEN, he removed the main fuse.
Given that he had turned off the consumer unit, this struck me as
excessively cautious, but what do I know?

Clearly not as much as you think.
He was taking adequate precautions against the fuse carrier/fuse/cut-out
falling apart when he pulled it.

I can see the need to do this with some old installations but is it
necessary with current designs of main fuses?

If you have the gear to hand, why would you *not* do it? It must be all
of 20 seconds extra to put on the gloves and visor.

The main issue here is the unknown unknowns... These guys are quite
often trained to do the specific job safely in *any* situation. So its
far simpler to have a one size fits all procedure, that does not require
detailed knowledge of the installation, or the upstream supply, and does
not need any great experience or knowledge of electrical installations
and how they might be molested out in the wild.

So yes you might be able to look at the style of cutout and be fairly
certain that its unlikely to short when you pull the fuse, and you can
see there is no load at the CU, hence you assume "low risk". However are
you *sure* that someone has not hacked about with the cutout - say to
try and illicitly power their grow room at some point in the past? Or
that someone has not wired an additional submain feed to another CU at
the incoming terminals of the main CU, so that turning it off, still
leaves attached loads elsewhere?




--
Cheers,

John.

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