On Wednesday, March 11, 2015 at 10:26:29 AM UTC, The Other Mike wrote:
On Tue, 10 Mar 2015 10:21:26 -0700 (PDT), wrote:
There is an issue but I think its being exaggerated. Using meters on 5-32A fused/mcb circuits is a very different ballgame to exploding them with 25,000A. Its when you're probing about inside a live CU that you really need that CAT certification. Most diyers are never going to do that.
I disagree, a DIY'er could do exactly that.
so we agree that a diyer could do that, but most never do.
Cheapo meters are fecking lethal anywhere near mains,
nonsense
****ty design, glass
fuses, no blast shields, faked certification, crap probes. The non professional
user won't even begin to understand that there could be a problem. The properly
designed led testers and volts sticks are far safer than cheap and patently
uncertifiable 'universal' test meters.
properly designed voltsticks and properly designed multimeters are better than crap designed both. Not news.
http://ecmweb.com/arc-flash/case-deadly-arc-flash
As for being protected by the installation, move away from the consumer unit and
the wiring will help to some extent.
not really. Cable resistance won't reduce i squared t to a safe value, the CU MCB is what reduces the user's risk.
But protective devices on the installation
might not always come to your aid, i've had an MK RCD fail closed at home in the
past couple of years (only discovered at a routine test, it could have been
yes, it happens. A milllion to one multiplied by a thousand to one is... a very small risk indeed. That's why there isnt just one category. When you work north of the CU protective devices then you do need a suitably rated meter, but about 99% of diyers never do that. The ones that do need to know not to use cheapo meters _there_.
In the sad death you repeatedly refer to, a totally unrated untested meter was used in a 3phase 480v breaker panel supplying an entire shopping mall. I think we all agree cheapie meters should not be used in such a place. Downwind of a 5A fuse is a very different matter, something the cat system recognises.
NT