8 Oct
2007
8 Oct
'07
10:25 a.m.
On 8 Oct 2007 at 2:28, Tothwolf wrote:
I usually check for voltage 3-4 different ways before
I work on mains
wiring. My first test is usually with a non-contact voltage tester. Then I
test with my good old Square D Wiggy tester. If I'm really concerned, then
I'll check it with my Fluke DMM. Even after all those show something dead,
I still check it with the back of my hand or finger.
When I worked in industry, I was informed that the nice Simpson 260
VOMs were to be used where there was something to measure, not for
safety checks. And always be aware that there are lots of DIY
"fixers" out there.
For safety checking, one can use a Wiggy (still made), or a neon bulb
probe. Check for voltage before pulling the breaker and afterwards.
Check each line against ground in case some idiot swapped the lines.
If it's a three-phase setup, check each line against the others and
against ground.
Secure the breaker in the off position, lest someone come by and
think that it's been tripped and decides to do you a favor. In
industry, this meant locking the disconnect box with your lock and
tag. If there are fuses in addition to a disconnect, pull the fuses
and put them in your pocket or tool pouch--don't leave them by the
disconnect box.
In residential installations, this may not be possible, so I'll use
good old duct tape over the breaker handle. Not perfect, but better
than nothing.
Wear shoes with rubber soles. Mains work should not be done when one
is shoeless. While you may be certain that a circuit is "dead", work
as much as possilbe as if the circuit were live.
I was chatting with one of our electrical co-op's linemen. He
mentioned that when dealing with outages, that disconnected lines
sometimes aren't. Apparently some workers have been surprised when
some enterprising homeowner decided to fire up his portable generator
without pulling the main disconnect.
Cheers,
Chuck