Clayton Luckie wrote on Sun, 30 October 2005 17:25 |
I just heard news of a pastor who was electrocuted today because he was handed a mic while he was standing in the baptismal. This is of course a very dangerous thing, especially if there is phantom power on this mic. |
Clayton Luckie wrote on Sun, 30 October 2005 18:25 |
Hey folks I just heard news of a pastor who was electrocuted today because he was handed a mic while he was standing in the baptismal. This is of course a very dangerous thing, especially if there is phantom power on this mic. Just a reminder to church tech teams out there that we can do a lot to protect people when micing baptisms. I use an SM81 just outside of the water area, but far enough away that it would not easily fall into the water. I also put a windscreen on it, just in case someone decides to grab the mic while standing in the pool. This would hopefully keep water from reaching the mic element and completing the circuit through the pastor. Most importantly, I remind whoever the pastor is that the mic is not to be touched while they are in the water. Please be safe when working with this stuff. Sometimes we can forget how dangerous things can be. [Update] I just read that this pastor has passed away because of this accident. This is serious stuff, folks. Please be careful. I also want to say that I do not want to mention the name of this church, because I do not want to bring any undue grief to them in this time. This message is not at all an indictment of the tech team at this church, but just a reminder to us church sound workers to take extra precautions in this area. If you are at all effected by this pastor's death, I'm sure you will hear through your church. cl |
Clayton Luckie wrote on Mon, 31 October 2005 09:38 |
Do you go to this church? cl |
Stephen B. wrote on Mon, 31 October 2005 10:17 |
This is a very tragic thing that has happened. I find it really hard to believe that this church would have had a bad wiring job considering their permanent worship leader is one of the giants of contemporary worship music. How much more serious are the ramifications if the church was wired professionally? Remember that right now here in Waco, we are primarily concerned with supporting the family and friends of the pastor with prayer and love. |
Mark Smith wrote on Mon, 31 October 2005 12:12 |
While ground loops can cause hum, I can't think of a situation where you could have enough current capacity to cause a problem... Maybe with two completely seperate services and grounding systems, but you still usually have no more than a couple of ohms impedance between the two grounds and that is an outside number. Any thoughts? |
Mark Smith wrote on Mon, 31 October 2005 12:30 |
I don't know about the lab, but I think here we really are trying to understand what happened and hopefully learning how to make sure this tragedy doesn't happen again. The important thing for all of us to remember is no matter the cause, someone lost their life and that is truly regretable. |
Mark Smith wrote on Mon, 31 October 2005 13:27 |
Since the different grounding systems have a maximum impedance of about 15 ohms (making assumption both are "grounded")and the body has a minimum wet resistance of about 1000 ohms, only 1.5% of the current goes through the body. |
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Since we are dealing with 2 GROUNDING systems, not a hot, the voltage difference between the two systems would have to be a minimum of 1,319.5 volts. I don't know of a situation where you would see this. |
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Unfortunately I think we saw a main power contact here and it is sad that it happen. |
Mark Smith wrote on Mon, 31 October 2005 16:07 |
With your insulation statement, My understanding of insulation is that it has an almost infinite impedance up to it's breakdown voltage. At that point the characteristics change. |
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I have seen grounds spark over too, but not in a situation where 120/240 is the primary voltage on the system. (saw it on 161 kV and it was a bad day) |
Mike McCloskey wrote on Wed, 02 November 2005 12:42 |
I will bet that many churches will review their configuration for baptisary mic's in light of this unfortunate accident. Many will assume that since they aren't using phantom power that all is OK (obviously a misnomer). But it appears that the only fully safe solution would be the wireless mic on a boom. A second would be a hanging condensor choir mic, well out of reach. Am I missing something? |
Michael 'Bink' Knowles wrote on Wed, 02 November 2005 20:52 | ||
At least one more safe solution to the problem would be a wired dynamic mic connected to the mixer through an isolation transformer with pin 1 not connected and its housing not grounded. -Bink |
Mike McCloskey wrote on Wed, 02 November 2005 14:42 |
I will bet that many churches will review their configuration for baptisary mic's in light of this unfortunate accident. Many will assume that since they aren't using phantom power that all is OK (obviously a misnomer). But it appears that the only fully safe solution would be the wireless mic on a boom. A second would be a hanging condensor choir mic, well out of reach. Am I missing something? |
william wrote on Wed, 02 November 2005 16:53 |
In the quest for an idiot-proof solution, one thought might be to install a mike jack in a location convenient to the bapistry incorporating Bink's suggestion of transformer isolation that's permanently installed out of sight behind the mike jack. It isn't completely bulletproof, but would probably work until the church redesigned their baptistry... |
DTownSMR wrote on Thu, 03 November 2005 12:44 |
I'll show my ignorance here. Would placing the mixing desk (or whatever is connected to the jacks on the chancel/stage) on a GFI circuit prevent such a tragedy? |
william wrote on Thu, 03 November 2005 17:16 |
JR--You're right, of course. I was way too quick posting my response to Bink's well thought out "fix", and didn't mean to imply that Bink wasn't aware of the impossibility of an absolute fix. As you and others have pointed out, there is a constellation of things that, taken individually are each Ok and even within code; but when they all line up just right can lead to serious or even fatal consequences. The scary thing is that even if we all communicate this event to all of clients who practice full immersion baptisms (and I feel obligated to do just that) this will still happen again. In a couple of years people will have forgotten... |
DTownSMR wrote on Thu, 03 November 2005 13:44 |
I'll show my ignorance here. Would placing the mixing desk (or whatever is connected to the jacks on the chancel/stage) on a GFI circuit prevent such a tragedy? |
JimCreegan wrote on Fri, 04 November 2005 02:27 |
Of course it would be absolutely illegal to have any power on the pool not on GFCI, so if everything the sound system was plugged into was also GFCI protected you would be safe, unless one of the GFCIs failed. Nine volts on a wireless battery has probably only caused a tingle on the tongue of a sound tech with no voltmeter handy, nothing more. JimC |
Mark Smith wrote on Fri, 04 November 2005 08:17 | ||
As for me, it is much easier to limit anything around the baptistry to wireless. It makes my life simplier to not have to worry about what could happen. regards. |
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course it would be absolutely illegal to have any power on the pool not on GFCI |
Mike McCloskey wrote on Fri, 04 November 2005 15:06 | ||
I am no electrician, but I think that a GFCI might not be required by code. A recept ocer the pool would have to be, but not the heater. |
Stephen B. wrote on Mon, 31 October 2005 09:17 |
This is a very tragic thing that has happened. I find it really hard to believe that this church would have had a bad wiring job considering their permanent worship leader is one of the giants of contemporary worship music. How much more serious are the ramifications if the church was wired professionally? Remember that right now here in Waco, we are primarily concerned with supporting the family and friends of the pastor with prayer and love. |
Scott R (Raymond) wrote on Fri, 04 November 2005 17:36 | ||
When I saw Waco, my thoughts went to David C. Is this who your refering to? He's been here in the theatre. Our prayers go out to everyone there. |
JimCreegan wrote on Fri, 04 November 2005 08:06 | ||||
Exactly my point, and it seems a consensus. The other thing to think about though, is if there are baptismals or any pools, hot tubs, whatever, around that have mains power, installed before the GFCI regulations they need to be updated. JimC |
Steve S. wrote on Sat, 05 November 2005 18:59 |
...Wireless mics are certainly a good idea, but in my opinion, a GFCI breaker on the baptistry equipment is morally if not legally required-there are too many other potential ground paths (like someone standing on a damp floor,etc, etc). My wholesale cost for the proper breaker for ours is $154 vs around $30 for a standard breaker. A lot of money until compared to the value of a life. By the way, ours was installed by a professional (not me!)-don't assume they did it right! |
Marty McCann wrote on Mon, 07 November 2005 09:51 |
A music dealer in Waco reported the following regarding this thread: >>> "xxx xxxxxx - xxxxxxx" <xxxxxxx@xxxxxxxxxx.com> 11/05/05 12:32PM >>> The church was wired by members not contractors when it was converted to a church from a safeway. The wiring was not up to code and caused there to be current running through the baptistry. The mike just acted as a ground. |
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...The church was wired by members not contractors when it was converted to a church from a safeway. The wiring was not up to code and caused there to be current running through the baptistry. The mike just acted as a ground. |
Mike McCloskey wrote on Mon, 07 November 2005 21:33 |
While the information from a local music store is very plausible, and may be well informed, it might be just as accurate as our guessing. Checking the church's websitwe reveals that the cause is as yet to be determined. |
JIMGUNDLACH wrote on Thu, 24 November 2005 19:35 |
It's 2005. Use a wireless mic. 9V bats don't kill people. |