How much/what electrical danger performing on a covered stage during rain?

Does anyone use 1:1 120v isolation transformers?

Doesn't folks plug EVERYTHING into a GFI? If the GFI is tripping, You Have a Problem -- fix it.

Clearly what's needed is fiber-connected mikes, both vocal and instrument...

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A host is a host from coast to coast.................wb8foz@nrk.com
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Unless the host (that isn\'t close).........................pob 1433
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The metal screen on an SM58 or SM57 is grounded. The guys that touch the mic with the guitar strings all learned that if your lips hit the mic grill, the whap that hits you in the face is like a big blue ball of lightning, followed by little fireflys floating around for a few more minutes while you get your senses back. It pretty much ruins the whole set for me. What causes it is the stage backline is plugged into a breaker box running off phase A, the lights are on phase B, and the sound is on phase C, and they are all drawing different currents, so the neutral is floating about 20V above ground because of the unbalanced load. I can test a 9V battery by licking it, but 20V is like a mule kick.

elevator

Shows that the push to elimanate DC was still on in 2005. I think it is still on going. The Steam pipe that exploded over the summer was a Con Ed supply for building uses. I have not heard of any efort to eliminat that service.

--
Stephen B.

"BobG"

** That sounds like copping the full 120 AC on the lips.

** WTF has the neutral voltage got to do with it ?

Must be a VERY badly wired AC supply system for the safety ground on any circuit to be more than 1 volt compared from the ground on any other.

Needs to be condemned.

....... Phil

Sometimes the person is in contact with another current source and is killed by touching a grounded microphoe or instrument, so somone can die if the sysytem is properly installed. A GFI won't detect the current flow to earth from a different source.

There was a recent news story of a pastor dying while baptising someone. A lot of plumbing is now all PVC, so a bad heating element that is shorthed to its casing won't trip the breaker, or blow a fuse. The skin of a water heater is grounded, but the tank may not be.

The man was waist deep (or more) in the water when he picked up the grounded microphone, and couldn't let go.

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

simply not true what causes it is a ground fault in the backline gear(99%) of the time and the other % would be other fauklt conditiopns there is nothing inherently unsafe in useing 3 phase power george

>

what i find more than I care ton is some yahoo removes the 2 slot edisons and replaces them with the grouded version , only there is no ground connected on the back

every outlet get tested before it gets used George

like what? your cell phone? here in the USA wireless micsare in turmoil because the government is selling the bandwidth it exists on george

In the uk the regulator (Ofcom) is preserving a chunk of UHF spectrum from the digital switchover for wireless mics.

d

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Pearce Consulting
http://www.pearce.uk.com

Idiot. Live performers use wireless hooks EVERY DAY.

you are so out of the loop no more debate can be had tell me about the last time you set up 35 wireless mics for a show I have

oh and while you at it can you name the protocol that will/is replaceing uhf /vhf as a transmission mode? put up or shut up jerk

Please note the word "EVERYTHING" above. Not some of the amps, one of the mixers... everything on stage running from one GFI or another... [Except the drummer, of course, who's likely running on crank, but at least he's not a current source...]

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A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that\'s close........[v].(301) 56-LINUX
Unless the host (that isn\'t close).........................pob 1433
is busy, hung or dead....................................20915-1433

What do you think about Audio Technica's SpectraPulse?

I think its exciting also odd that it took 100 years to bring it to market myself I will not buy or sell any more traditional wireless mics until this bandwidth stuff settles and I am down to just 6 in my inventory but I hope to get some time to talk to the AT guys at AES George

What causes it is the stage backline is plugged into

I have not seen a show hooked up this way with a single 3 phase hook up we put the sound INCLUDING stage and back line on 1 leg and lights on the other two bigger venues have several 3 phase disconnects generall sound will take the smaller(200 amp or so) and lights will take the larger(4-600 amps) but still the backline is IME always on the same leg(s) as the sound george

"Michael A. Terrell" wrote in message news: snipped-for-privacy@earthlink.net...

That is why I said earlier to touch the mic with the back of your hand before grabbing or kissing it.

peace dawg

Sometimes, but the NEC in the US limits what you can do as far as breaking safety grounds, when isolation transformers are in use. Normally folks use isolation transformers only as low-pass filters, really.

NEC says you have to use GFIs on most circuits outside, but not everyone does. Personally, although GFIs are prone to falsing in high RFI environments, I think they have saved more lives than they are given credit for.

Yes, but now you need to get power to the mike, as well, since the fibre can't carry it. There are plenty of systems with fibre links between the stage box and the console; you can see one at the National Gallery of Art in their sculpture garden system. Plenty of isolation, and you can run the skinny little fibre into an existing power conduit rather than having to pull a big snake. Of course you now have to set the console trims on the stage box which can be a pain without a big stage crew.

--scott

--
"C\'est un Nagra.  C\'est suisse, et tres, tres precis."

This is a sign you got a BIG problem, not just with an unbalanced load, but with poor neutral-ground bonding.

This is when it's time to walk offstage and cut your losses.

--scott

--
"C'est un Nagra.  C'est suisse, et tres, tres precis."

Right. The GFI dectects only an imbalance in neutral and hot currents on the device it's protecting.

This means that EVERYTHING on the stage area needs to be on a GFI, and that includes backline. If an amp is popping the GFI, you need to fix it.

Now, I know that outdoor festivals it's very common to defeat GFIs in order to deal with backline equipment that has ground fault issues. I don't have a real problem with this, IF the power system grounds are good enough and the crew is watching out.

Note that he was electrocuted by a circuit which BY LAW needs to be on a GFI, and has been for more than a decade now.

See, in a perfect world, there are no electrical leakage issues. But the ground is there to protect you when things go wrong. And the GFI is there to protect you when the ground goes wrong. It's a belt-and-suspenders thing.

Maybe you'll never need the ground to be there. Probably you'll never need the GFI. But if you SHOULD need it, you'll be really glad you have it.

--scott

--
"C\'est un Nagra.  C\'est suisse, et tres, tres precis."