ECN Forum Forums General Topics of the Trade General Discussion Area Pastor electrocuted during baptism

Ohhhh thats bad!

-Hal

Hi Joe:

Hope you didn't think I was trying to imply you were being ridiculous, I was quoting someone else to expand on thier comments.

I hope my explanation of how a phantom supply works was accurate...

I like the testing method you suggested in your first post...it would still leave open however which source the voltage was coming from, the pool or the mic...of course, if you tested each to a known ground than the answer would be clear.

Crossover distortion, that was bad!!

Well Joe, you did say that you wonder if some of these cases might be caused by the "phantom power" supply.

Mxslick gave an excellent description of what phantom powering is and how it is applied so you can see why it couldn't be an issue with electrocution.

Edit: Oh yeah, I really do like the idea of someone walking around with a voltmeter before a performance or just periodically checking for leakage or voltage on the mics and instruments. Should be made mandatory!

-Hal

[This message has been edited by hbiss (edited 11-10-2005).]

I didn't get my feelings hurt folks & I understood how I could've been misunderstood. The posts got pretty divergent and I was responding to parts of a couple of them.

I do agree that you would have to have a pretty messed up mic(and musician) to touch both ends of the phantom supply with moist body parts.(Nor would I pay to watch a movie showing such a thing)

I don't recall the article saying, but it is quite possible that this fatal shock didn't damage a single piece of equipment. I find it very hard to believe that he provided a path to ground for installed equipment. This should be no mystery to local authorities if they took control of the accident scene and have the equipment. It would be extremely easy to reproduce the conditions.(except for the Assistant Pastor's part)<G>

There was other talk about zaps, hum, 3rd harmonic and the like. Remember to avoid letting the cases of your XLR(3 pin happy face) connectors touch concrete floors. Ground loops are a common source. If your noise source is 3rd harmonic, it shouldn't sound like 60 Hz. For my band, I would choose the members whose families were most likely to sue me first. Then, I would plug their amps into isolation transformers and tie their chassis into a star grounding scheme. But seriously, I would not let a hot chassis situation go because anything that zapped you, might have been able to kill you.
Plus, it is most likely causing distortions in your audio path now.
Joe

I just want to add that mxslick did do a very thorough explanation of phantom power. He did mention that the phantom supply will shut down to protect gear. I'm thinking that most probably keep operating but have sufficiently high output resistance that they just get pulled down to near zero volts across the load.

I also wanted to add that I found these forums by accident. You're an impressive bunch of folks with probably centuries of combined experience. Thanks for making me feel welcome here!!!
Joe

Aw, shucks, Joe, now I'm blushing...thanks for the compliment!


And oh yeah, welcome aboard! You'll find a lot of great info here too. Don't be afraid to browse the archives of all the threads (using the page numbers at the very bottom of your screen when looking at a selected topic area) there are a lot of older topics that are really informative!

[This message has been edited by mxslick (edited 11-12-2005).]

Some light reading of the big book... and I came across this gem...

I've not seen a phantom power circuit that's designed to shut down. Normally, they just have a 6800 ohm (IIRC) resistor in series with the 48V phantom supply before it connects to the mic connector.