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Re: Want to move to all 208V for server racks
- From: Michael Painter
- Date: Sat Dec 04 21:24:46 2010
Kevin Oberman wrote:
Lead-acid batteries can deliver way over 100 amps of current and a
conductor across "safe" voltage will get hot and, if not heavy enough,
will vaporize. The temperatures attained can cause major burns and,
should the metal vaporize, can damage tissue so severely that fingers
have been lost when the blood vessels were cauterized.
While safety rules often list voltages under 50 as being safe, it is
still important to exercise caution like removing rings, bracelets and
the like.
I can't remember what I was trying to accomplish, but when we were building a telco office, and after making sure I was
completely "demetalicized", I had to climb up the ladder and sit on one of the 48V 1/4"x4" (2-sandwiched) copper buss-bars
and lay out accross the others, everything being already 'hot'. Unnerving to be sure.
I can also recall one morning at the S.P. Railroad when they called all us 'Diesel Electricians' together and showed us a
wrench from graveyard shift.
Most of one end was burned off, and the other end was welded to the thick, gold, wedding-band which had been cut off the
guy's finger on the way to the hospital.
They reiterated the mantra, 'when working with batteries, always disconnect the grounded/carbody side first'.
At IBM, we had a ritual before working on -anything-. Take off rings, watches/bracelet, tie-clasp and put into pocket.
Tuck tie into top opening of shirt (white) so your neck doesn't get broken when tie catches on all the spinning crap.
Even after the 360/370 came along you could always tell the old hands...the guys with their tie tucked in.
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