phantom power electrocution

I followed that story, and it turned out the fault was not with the
sound system, but with the pumping / filtration system in the hot tub /
baptistry. Aparently it wasn't gournded properly, but when the pastor
grabbed the mic, the ground went through him and into the mic cable.
Well....something like that anyway.
 >> Stay informed about: phantom power electrocution 

Thanks Simon- where did you see that info?- I figured the trade mags
might have covered
it, but I haven't kept up with them lately.
 >> Stay informed about: phantom power electrocution 

jflenniken wrote ...
> Hi- a few months ago here in Texas, a church's pastor died one Sunday
> morning when he grabbed a microphone while standing in the baptistry.
> Was something horribly mis-wired, or shorted, or does phantom carry
> enough current for this to be expected? This question would also extend
> to the stories I've heard about musicians getting zapped when their
> lips touch the windscreen. Is this equipment or installation failure,
> or a normal job hazard?

No, full 48V DC phantom power is not dangerous unless you
connect it to electrodes poked into someone's heart, etc.

If you had followed up on that news story you would have seen that
the problem was with the water heating unit in the tank, not with
anything to do with the sound system. Nevertheless, putting any
wired sound equipment within reach of someone standing in water
is always a bad idea.

Musicians getting zapped by the microphones seems more like a
problem with the typical guitar amps which have really lousy
fault current isolation from the power lines. As with the original
story, the sound system microphone only provided a return path
for the fault current which originated elsewhere.
 >> Stay informed about: phantom power electrocution 

Re: phantom power electrocution

Group: rec.arts.movies.production.sound Date: Fri, Feb 24, 2006, 2:28pm
(EST-3) From: jflenniken.RemoveThis@namb.net
Thanks Simon- where did you see that info?- I figured the trade mags
might have covered
it, but I haven't kept up with them lately. <<<<<<

There was a huge thread on this topic on rec.audio.pro a while back.
Search the Google archives for more.

Eric
 >> Stay informed about: phantom power electrocution 

On Fri, 24 Feb 2006 14:27:30 -0500, jflenniken DeleteThis @namb.net wrote
(in article <1140809250.788363.279520 DeleteThis @e56g2000cwe.googlegroups.com>):

> Hi- a few months ago here in Texas, a church's pastor died one Sunday
> morning when he grabbed a microphone while standing in the baptistry.
> Was something horribly mis-wired, or shorted, or does phantom carry
> enough current for this to be expected? This question would also extend
> to the stories I've heard about musicians getting zapped when their
> lips touch the windscreen. Is this equipment or installation failure,
> or a normal job hazard?
>
> Thanks, John F.
>

God was simply calling him home. It didn't have anything to do with Phantom
Power.

Ty Ford


-- Ty Ford's equipment reviews, audio samples, rates and other audiocentric
stuff are at www.tyford.com
 >> Stay informed about: phantom power electrocution 

On 24 Feb 2006 11:27:30 -0800, jflenniken DeleteThis @namb.net schreef:

>Hi- a few months ago here in Texas, a church's pastor died one Sunday
>morning when he grabbed a microphone while standing in the baptistry.
>Was something horribly mis-wired, or shorted, or does phantom carry
>enough current for this to be expected? This question would also extend
>to the stories I've heard about musicians getting zapped when their
>lips touch the windscreen. Is this equipment or installation failure,
>or a normal job hazard?

Hmmm, how fast did the gaffer leave the set that specific day ?...



R





--
Http://www.xs4all.nl/~tuig/index.html
 >> Stay informed about: phantom power electrocution 

In article <1140812592.863639.199070 RemoveThis @i39g2000cwa.googlegroups.com>,
Simon <simonpaine RemoveThis @yahoo.com> wrote:

> I followed that story, and it turned out the fault was not with the
> sound system, but with the pumping / filtration system in the hot tub /
> baptistry. Aparently it wasn't gournded properly, but when the pastor
> grabbed the mic, the ground went through him and into the mic cable.
> Well....something like that anyway.
>
Hmm..anyway this pastor spoke too much ...
 >> Stay informed about: phantom power electrocution 

The musicians getting a tickle when they touch the windscreen is probably
due to a bad ground in their instrument amp, not phantom power on the PA.
Besides, SM57s don't need phantom...

--
Correct address is spell out the letter j, AT dplaydahtcom
Clio- and Emmy-winning sound design
Learn audio for video at www.dplay.com
 >> Stay informed about: phantom power electrocution 

jflenniken.RemoveThis@namb.net wrote:

> Hi- a few months ago here in Texas, a church's pastor died one Sunday
> morning when he grabbed a microphone while standing in the baptistry.
> Was something horribly mis-wired, or shorted, or does phantom carry
> enough current for this to be expected? This question would also extend
> to the stories I've heard about musicians getting zapped when their
> lips touch the windscreen. Is this equipment or installation failure,
> or a normal job hazard?

No, phantom power does not supply that much current.

However, with a sly smile I inform people I rig with wireless that if
they drop the transmitter into the commode it could electrocute them. I
then suggest -- that when nature calls -- they come have me pull the
transmitter to avoid the danger. They seem happy to cooperate.

John Blankenship, C.A.S.
Indianapolis
(email: my initials at mw daht net)


 >> Stay informed about: phantom power electrocution 

"John Blankenship" <"John Blankenship"> wrote in news:440227a4$0$7323
$39cecf19@news.twtelecom.net:

> No, phantom power does not supply that much current.
>

48 DC is widely used in telephony--the central office plant was full of it,
at least in the old days, and at very low impedance. It also appears on
the subscriber line at roughly 1 kohm impedance level. So on short
subscriber lines it is appreciably lower impedance than standard phantom
power.

As an intern in a switching systems design department at Bell Holmdel, I
was told by the old heads that while it was possible to get yourself
electrocuted by 48DC, it took real concerted effort. They were talking
about the central office risk, not subscriber line (as Edison's infamous
cat and criminal "demonstrations" sought to emphasize, DC is drastically
lower electrocution risk than AC, and 48 is fairly low voltage anyway).
The relatively high impedance of phantom power is a third safety factor,
probably less important than the first two.

Lest anyone suppose I said subscriber lines were completely safe, let me
remind folks that the ringing signal is AC, and more than 48V. It is
unusual to hurt people badly with it, but it deserves respect.

Peter A. Stoll
retired electrical engineer
audio amateur
 >> Stay informed about: phantom power electrocution 

"Eric Toline" wrote ...
> Re: phantom power electrocution
>
> Group: rec.arts.movies.production.sound Date: Fri, Feb 24, 2006, 2:28pm
> (EST-3) From: jflenniken.DeleteThis@namb.net
> Thanks Simon- where did you see that info?- I figured the trade mags
> might have covered
> it, but I haven't kept up with them lately. <<<<<<
>
> There was a huge thread on this topic on rec.audio.pro a while
> back. Search the Google archives for more.

Beware that only a fraction of it dealt with the actual topic
of electrocution, wiring, and audio equipment. The rest was
the expected anti-religion rant typical of r.a.p and a.a.p.l-s.
 >> Stay informed about: phantom power electrocution 

re: (as Edison's infamous
cat and criminal "demonstrations" sought to emphasize, DC is drastically
lower electrocution risk than AC,


tell us more ... was it Tesla who was the AC advocate?

wolf
 >> Stay informed about: phantom power electrocution 

> > tell us more ... was it Tesla who was the AC advocate?
>
> Tesla, Steinmetz and Westinghouse vs. Edison

Edison started a campaign to call execution by electrocution - then a
pretty cool idea among prison administrators - "Westinghousing".

But it's not a question of advocacy or public relations. It's economics.
It costs a lot less to distribute AC, because you can use transformers to
lower the current, and thus use smaller gauge wire for long runs. It
raises the voltage, but on a many-miles-long run from generator to user,
insulation is cheaper than copper. Even insulation plus transformers at
each end is cheaper.

--
Correct address is spell out the letter j, AT dplaydahtcom
Clio- and Emmy-winning sound design
Learn audio for video at www.dplay.com
 >> Stay informed about: phantom power electrocution