"rangerssuck" wrote in message
...
On Friday, June 5, 2015 at 1:01:39 PM UTC-4, Cydrome Leader wrote:
Ignoramus22165 wrote:
I was recently pulling some extremely small amount of MCM 500
copper
cables. Of course, it was legitimately purchased from the owner of
that building.

There was this one particular panel that was always live (hooked
up to
service drop) and under power.

The panel had two 800A switch boxes. The boxes were fed through
panel
busbars, with a big handle switch, then fuses, then terminals for
MCM 500
cables.

Both boxes were in the same condition, namely:

1) The switch was in the OFF position
2) The outgoing cables were already removed.
3) The whole panel was 480 volts

There was literally NO incoming power that was not disconnected,
back-fed, or anything.

And yet, on one box out of two, my "Sperry voltage tester"
registered
live voltage.

I then re-checked it with a voltmeter and found "40 volts" (sic).
And
thi sis in a 480 volt panel!

I needed to touch those busbars (switched off, remember) to unbolt
and
remove the fuses, since the fuses are $100 for 3. Out of abundance
of
caution, I brought in a wooden pallet, stood on wood, used a
socket
extension and was very careful not to touch anything, and
everything
worked out OK.

What's the proper move for this situation? Stand on wood or ground
the
stuff being worked on, then proceed?

I don't see in Iggy's post that all the breakers in the panel were
turned off. He did say that the panels weren't being back-fed, but...
I had a couple of APC Smart-UPS boxes that would, under battery power,
put out enough voltage from their line cords to give a pretty decent
shock. I did not measure the voltages, nor did I test them under load.
We just replaced the UPS boxes (which was scheduled anyway) and sent
the old ones off to a local guy who refurbishes them.
==============

On battery my APC1400 measures nothing line-to-line, but 20VDC from
either line to ground.
-jsw