On 07/09/2019 10:34, Mike Clarke wrote:
On 06/09/2019 13:18, John Rumm wrote:
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.

Yes, if you have the PPE gear available it makes sense to use it but I
was wondering if lack of suitable PPE would be a reason to not pull the
main fuse from a modern cutout.

On your own installation its an easier call, since you probably know the
history of the install, and what CUs there are, and how they are powered
etc. With a bit of experience you will also learn to recognise the
various types of main cutout in use, and which ones are inadvisable to
play with.

e.g. one should be wary of old metal clad things like :

http://wiki.diyfaq.org.uk/index.php/...CladCutout.jpg

Modern stuff like these are typically pretty low risk:

http://wiki.diyfaq.org.uk/index.php/File:TN-S1.jpg
http://wiki.diyfaq.org.uk/index.php/File:TN-S2.jpg
http://wiki.diyfaq.org.uk/index.php/File:TTModern.jpg

These are also ok, but do leave a fairly large area of exposed lave
metalwork after removal:

http://wiki.diyfaq.org.uk/index.php/...utandMeter.jpg



If in any doubt about whether you have removed all the load, then
sticking a clamp meter round one of the meter tails will soon tell you.

In other words which would be the greater risk on a modern domestic
installation. Working inside a consumer unit with its main switch turned
off but still live at the input side or pulling the main fuse after
switching off the consumer unit main switch.

Depends on what you mean by working inside. If you were replacing the CU
or doing other significant work, then yup isolate it first. If just
doing work on one circuit - say disconnecting it for testing or
isolation, then you can usually safely work with the power on as far as
the incomer of the main switch.



--
Cheers,

John.

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