5 Oct
2007
5 Oct
'07
12:41 a.m.
Hi all
From: ard at p850ug1.demon.co.uk (Tony Duell)
A friend of mine was nearly killed due to this. He tested some wiring for
voltage-to-earth and the meter said it was essentially dead. SO he
started workign, alas the meter was malfuctioning, and he got the full
mains volatege across him. He imediately went and bought an expensive mad
reliable neter.
I always short my screwdriver across the line before fitting, say, a light
socket or a switch.
This would be after turning the mains off and measuring.
Even when it's a brand new installation and the main breaker panel isn't
connected to the utility yet.
Yea, it might cause a helluva flashbang, but it beats walking that tunnel
towards the bright light.
W
5 Oct
5 Oct
6:24 a.m.
I always short my screwdriver across the line before
fitting, say, a
light socket or a switch.
[...]
Yea, it might cause a helluva flashbang, but it beats
walking that
tunnel towards the bright light.
I once deliberately bridged hot to ground with a screwdriver on a live
circuit - we were having trouble figuring out which breaker it was on.
It did make "a helluva flashbang", and it took some time - half a
minute? multiple minutes? - before I could see again; I was silly
enough to look right at it as I did it.
It also ate a nice little cavity about halfway through the screwdriver
shaft. The shaft was perhaps 5mm thick, and the cavity looked,
roughly, as though someone had drilled a 5mm hole whose centreline
passed through the surface of the shaft.
Oh, and the room smelled of vapourized copper and steel for a few
minutes. :)
I don't recommend this, except as (as Wouter describes it) a
belt-and-suspenders technique for making *sure* the line is cold. In
retrospect, it was a stupid way to do what I wanted done, and quite
probably reduced the life expectancy of that breaker substantially.
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
3:26 p.m.
Hi all
Not with one of my screwdriers you don't! I value my tools...
An electircal-engineer friend of mine toaught me the correct procedure.
Firstly, test the meter on a circuit you know is live. Then isolate the
circuit you want to work on, check that the meter shows it to be dead.
Then chekc the meter on a live cirucit again, to be sure it's not failed
between the first 2 tests. After that, for mains volage, (but nothing
higher)!, I'd brush the wiring with the back of my fingers, the idea
being that if by some fluke it is sitll live, the shock would throw me
off, not force me onto the terminals/
Said friend has a voltmeter used for small overhead power lines (up to
11kV or something). In the carrying case is a small 5kV-or-so
battery-operated PSU. You use that to check the meter is working
correctly before and ever seach test to see if a power line is dead.
-tony
From: ard at p850ug1.demon.co.uk (Tony Duell)
A friend of mine was nearly killed due to this. He tested some wiring for
voltage-to-earth and the meter said it was essentially dead. SO he
started workign, alas the meter was malfuctioning, and he got the full
mains volatege across him. He imediately went and bought an expensive mad
reliable neter.
I always short my screwdriver across the line before fitting, say, a light
socket or a switch. 
6 Oct
6 Oct
3 a.m.
Tony Duell wrote:
You've often said that you always purchase good quality tools so
I can see why you'd like to avoid damaging them, but damaging a
screwdriver is usually preferable to ending up halfway across
the room on your backside or worse (although if it's a vintage
screwdriver maybe the equation is a little harder to compute :-)).
At the point that he's shorting the wires, he already thinks that
the power is cut so it really is "him or the screwdriver: pick one".
Having said that, I do what you do and brush the back of my hand
across to be (more) sure that the power is off.
Antonio
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.488 / Virus Database: 269.14.2/1052 - Release Date:
05/10/2007 18:53
I always short
my screwdriver across the line before fitting, say, a
light socket or a switch.
Not with one of my screwdriers you don't! I value my tools...
6288
days inactive
6289
days old
3 comments
4 participants
participants (4)
-
arcarlini＠iee.org -
ard＠p850ug1.demon.co.uk -
cctech＠retro.co.za -
mouse＠Rodents.Montreal.QC.CA