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

[Deputy Dumbya Dawg]

I've heard of performers being electrocuted by a mic. If
someone is
performing on a covered stage when it's raining - not
necessarily with
lightning - or any other time for that matter - what should
be
checked/in place to make sure there's no danger to the
performer(s)?
(Other than not performing) Asked another way, what
potentially COULD
create a dangerous situation that some flunkies involved
with stage
operations/sound who don't know better might not check or
just might
fall between the cracks even with pros?

If someone doesn't like to just assume "it's all taken care
of" and
wants to be sure a loved one or friend who's performing is
safe, who
should they typically talk to and what questions should they
ask and
get clear answers to and/or what should they personally
inspect?

Any other stage safety issues that experience has taught you
to be
aware of?


Thanks for all input

http://elvispelvis.com/electrocuted.htm

Keith Relf of the Yardbirds came back from the other side and
told me not to play my electric bass in the bathtub.
http://elvispelvis.com/electrocuted.htm

But if you are not sure and are standing on the stage with
your bass and a mic giving you the evil eye- or are wondering
about touching any other piece of electrified equipment and
just want to KNOW that when your lips touch the mic you will
not get bit here is a little something you can do that will
let you know the mic will not bite.

Consider this a last advice as a LAST RESORT if all the other
advice in the thread has been followed and you left your
voltmeter home but are still a little scared.

Let the inside of your forearm or the underside of your biceps
touch your guitar strings. The skin that is tender is the key
and if it is a little moisten even better. . Tender flesh will
be much more sensitive to a shock than say your calloused
finger tips and the moisture will assist the current flow if
it is possible and hence you will be more sensitive to a shock
situation. . Now part one of the connection is done. Now with
the SAME arm lick the back of your hand and touch that to the
mic or other suspect equipment.

This does three things.
1) the moist sensitive moist flesh sets up more ideal
conditions for current to flow if such potential exists. The
same effects are exhibited with wet lips and sweaty hands.

2) the current takes a safer path since it only goes through
your arm not your heart.

3) put your flesh in the path in such a way that if current
flows and you are shocked your body's natural tendency to
clench onto what is shocking you is avoided. Your hand may
make a fist if you do get shocked but touching the mic with
the back of your hand will make you pull away from the
shocking element and prevent you from clenching onto the mic
with one hand and the bass with the other until your internal
resistance gets really high ( you are cooked and smoldering).

No shock. Probably safe till someone changes something
somewhere.

peace
dawg

 

[Dasvid McCall]

I all honesty I have not in 20 years of live sound seen a single"live mic"
I have experiacedproperly grounded mic when a "live" guitar player
touches the properly grounded mic
he get a shock
but its NOT THE MIC that has the juice
its the player
who is"live' AND THE CURRENT FLOWS TO GROUND THROUGH THE MIC
BUT THE mic does not SEND THE SHOCK TO THE PLAYER
gEOGRE

Assuming that the sound system is properly grounded this is true.
The exception is the sound guy that had a ground loop that was
causing the system to hum no matter what he tries tio do, so he
removes the grounding on some items in the system to fix it.
A long as all of the equipment gets tied together by the shields,
and they find ground somewhere in the system, you should be OK.
But it is considered to be a very bad practise these days.

There was a time when nothing had a ground on it, and the AC
connectors weren't even polarized. Engineers doing any decent
sized instalation (radio stations for instance) would actually
design their grounding system and connect a wire to the chasis
of each piece of equipment and run that back to a common
ground that ultimately found it's way to an "earth ground" as in
a long copper clad stake driven into the directly into the dirt.
Everything had ballanced ins and outs and most of the cabling
inside the racks only had grounds connected at the input end to
allow the earth ground from having multiple paths.

When they started putting grounds on power plugs, the engineers
hated it because the additional ground connections screws up their
carefully designed grounding schemes. The first thing they did when
a new piece of equipment came in was gut the ground pin off of it.

I think it may even be illegal to remove the ground pins now.

David

 

[Christian Marg]

Hello Phil,

It is COLOSSALLY DANGEROUS to use a class 2 item after it has become
WET !!!

The Bloggs goon is a TOTAL MORON !!

Would you care to tell us why instead of insulting the original poster
(which, in my opinion, is very unprofessional, as is "SHOUTING" in a
news posting)?

Maybe if you'd explain the danger of using a class 2 item, someone would
listen to you?

bye
Christian

PS: Sorry for X-posting, but I think that it is of no use to set a
"followup-to" after so much X-posting harm is done.

 

[Michael A. Terrell]

Hello Phil,



Would you care to tell us why instead of insulting the original poster
(which, in my opinion, is very unprofessional, as is "SHOUTING" in a
news posting)?

Maybe if you'd explain the danger of using a class 2 item, someone would
listen to you?

bye
Christian

PS: Sorry for X-posting, but I think that it is of no use to set a
"followup-to" after so much X-posting harm is done.

Ignore Phil. He hasn't had his morning bowl of medication for his
mental problems.

--
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

 

[VWWall]

When they started putting grounds on power plugs, the engineers
hated it because the additional ground connections screws up their
carefully designed grounding schemes. The first thing they did when
a new piece of equipment came in was gut the ground pin off of it.

The next thing we did, particularly on a remote, was to "reverse the
plug" to get rid of ground loop hum. Very few of the old units had
"polarized" two blade plugs, and the "adapters" had an unpolarized two
blade plug.

Probably the only reason we didn't kill somebody was that there were few
"musicians" plugged into high power amps!

 

[Dasvid McCall]

The next thing we did, particularly on a remote, was to "reverse the plug"
to get rid of ground loop hum. Very few of the old units had "polarized"
two blade plugs, and the "adapters" had an unpolarized two blade plug.

Probably the only reason we didn't kill somebody was that there were few
"musicians" plugged into high power amps!

Some guitar amps had a switch that allowed you to switch which side
of the line would be referenced to the chasis and shielding. It wasn't a
direct connection though, it went through a capacitor so the current was
limited to a trickle. After you connected everything up, you would try the
switch in both positions to see which side gave you the least hum.

David

 

[Guy Macon]

Consider this a last advice as a LAST RESORT if all the other
advice in the thread has been followed and you left your
voltmeter home but are still a little scared.

Let the inside of your forearm or the underside of your biceps
touch your guitar strings. The skin that is tender is the key
and if it is a little moisten even better. . Tender flesh will
be much more sensitive to a shock than say your calloused
finger tips and the moisture will assist the current flow if
it is possible and hence you will be more sensitive to a shock
situation. . Now part one of the connection is done. Now with
the SAME arm lick the back of your hand and touch that to the
mic or other suspect equipment.

This does three things.
1) the moist sensitive moist flesh sets up more ideal
conditions for current to flow if such potential exists. The
same effects are exhibited with wet lips and sweaty hands.

2) the current takes a safer path since it only goes through
your arm not your heart.

3) put your flesh in the path in such a way that if current
flows and you are shocked your body's natural tendency to
clench onto what is shocking you is avoided. Your hand may
make a fist if you do get shocked but touching the mic with
the back of your hand will make you pull away from the
shocking element and prevent you from clenching onto the mic
with one hand and the bass with the other until your internal
resistance gets really high ( you are cooked and smoldering).

No shock. Probably safe till someone changes something
somewhere.

Before doing the above, touch the guitar strings to the
microphone. A guitarist I know was in the habit of doing
that, and one day a GFCI tripped during sound check.

 

[Scott Dorsey]

The exception is the sound guy that had a ground loop that was
causing the system to hum no matter what he tries tio do, so he
removes the grounding on some items in the system to fix it.

We call these people "idiots" and "unsafe" and I have seen more than
one guy fired on the spot for doing precisely that. This is not
an acceptable behaviour.

We have plenty of iso boxes with 1:1 transformers that allow anyone
to break signal grounds at any point. Anyone that does an outdoor
festival without such things is not competent.

A long as all of the equipment gets tied together by the shields,
and they find ground somewhere in the system, you should be OK.
But it is considered to be a very bad practise these days.

It has ALWAYS been considered to be very bad practice and you can NEVER
count on signal grounds providing a reliable safety earth. This is in
part because signal lines are always being moved around and someone may
briefly disconnect and repatch one. When you see a spark when you repatch
a cable, something very bad is happening and equipment is bound to get
damaged.

There was a time when nothing had a ground on it, and the AC
connectors weren't even polarized. Engineers doing any decent
sized instalation (radio stations for instance) would actually
design their grounding system and connect a wire to the chasis
of each piece of equipment and run that back to a common
ground that ultimately found it's way to an "earth ground" as in
a long copper clad stake driven into the directly into the dirt.
Everything had ballanced ins and outs and most of the cabling
inside the racks only had grounds connected at the input end to
allow the earth ground from having multiple paths.

And this can be a very reasonable configuration for a permanent installation
as long as EVERYONE recognizes the grounding scheme and follows it (and
that may require an orientation for new hires). It is not reasonable or
reliable in field operation, nor has it ever been acceptable in the field.

When they started putting grounds on power plugs, the engineers
hated it because the additional ground connections screws up their
carefully designed grounding schemes. The first thing they did when
a new piece of equipment came in was gut the ground pin off of it.

I think it may even be illegal to remove the ground pins now.

It has been against the NEC here in the US, at least since the early seventies.
--scott

 

[David McCall]

We call these people "idiots" and "unsafe" and I have seen more than
one guy fired on the spot for doing precisely that. This is not
an acceptable behaviour.

I'd agree with that.

We have plenty of iso boxes with 1:1 transformers that allow anyone
to break signal grounds at any point. Anyone that does an outdoor
festival without such things is not competent.

Back when I was doing concert sound in the late 60s these things were
available, but not at all common.

It has ALWAYS been considered to be very bad practice and you can NEVER
count on signal grounds providing a reliable safety earth. This is in
part because signal lines are always being moved around and someone may
briefly disconnect and repatch one. When you see a spark when you repatch
a cable, something very bad is happening and equipment is bound to get
damaged.

I agree with that as well. Sparks and smoke are 2 things we are all better
off without.
Unless you live in GB where you depend on sparks to deal with your lights

And this can be a very reasonable configuration for a permanent
installation
as long as EVERYONE recognizes the grounding scheme and follows it (and
that may require an orientation for new hires). It is not reasonable or
reliable in field operation, nor has it ever been acceptable in the field.

Yes, field equipment gets swapped around too much to use this approach,
but as you say, it is against regulations to remove grounds, which makes
grounding schemes in permanent racks more complicated than it was.

It has been against the NEC here in the US, at least since the early
seventies.

That sounds about right. I don't remember grounded outlets being very common
in the early 60s and don't remember any in the 50s. I still run into quite a
few
outlets with no ground even today. If you are lucky, the box will be
grounded and
you can just use an adapter. If the box isn't grounded, then I guess you
should
start looking for a water pipe.

David

 

[Benj]

I all honesty I have not in 20 years of live sound seen a single"live mic"
I have experiaced properly grounded mic when a "live" guitar player touches
the properly grounded mic
he get a shock
but its NOT THE MIC that has the juice
its the player
who is"live' AND THE CURRENT FLOWS TO GROUND THROUGH THE MIC
BUT THE mic does not SEND THE SHOCK TO THE PLAYER

This may or not be true but can often happen.
Generally speaking as Scott notes the danger from gear on stage comes
from improper grounding. The use of clipped "ground buster" plugs and
the rest is a huge No-No. The whole idea of proper grounds is that IF
rain causes a short to say the mic stand, the fact that it is grounded
will simply blow the fuse rather than kill someone.

BUT the catch is that mics and sound systems are very prone to hum.
And soundmen tend to take a quick and easy approach to hum reduction.
"ground busting" is one such approach. Some gear even has ground-lift
switches built in! All this can work fine if you "bust" signal ground
and not safety ground. But obviously the potential for mistakes can be
great!

As for the above comments, they make sense too. Dig. A singer
typically also plays a guitar. The guitar plugs into an amp (often
"vintage" of unsafe design) on stage. The mic on the other hand is
feeding some professional gear run (presumably) by a pro. The
likelihood of the mic stand being soundly grounded is great. Thus, if
the guitar amp due to rain or other factors develops a voltage with
respect to earth ground, the guitar player touching the mic will
receive current not from the mic but from the faulty amp through his
guitar which flows out through the soundly grounded mic. Since it is
not common practice to run a heavy earth ground to the chassis of the
guitar amp on stage, there is a great potential for such an accident!

 

[Guest]

This may or not be true but can often happen.
Generally speaking as Scott notes the danger from gear on stage comes
from improper grounding. The use of clipped "ground buster" plugs and
the rest is a huge No-No. The whole idea of proper grounds is that IF
rain causes a short to say the mic stand, the fact that it is grounded
will simply blow the fuse rather than kill someone.

BUT the catch is that mics and sound systems are very prone to hum.
And soundmen tend to take a quick and easy approach to hum reduction.
"ground busting" is one such approach. Some gear even has ground-lift
switches built in! All this can work fine if you "bust" signal ground
and not safety ground. But obviously the potential for mistakes can be
great!

Well, one of the first and most strict things I teach the soundguys that
work my shows is electrical saftey
IMO anyone who trys to cure a hum by defeating a saftey groung is simply a
idiot, not a "soundguy" , soundguys KNOW better
idiots dont

So IMO it may be symantics to you
but your not a soundguy unless you understand the job of a soundguy
and one of the most important aspects of that job is saftey
and electrical saftey is lesson one

 

[Scott Dorsey]

Back when I was doing concert sound in the late 60s these things were
available, but not at all common.

Part of that is because in the late 60s, everything was transformer-isolated
and there was already a transformer in the input and the output of the console
and on the input of the amp. So telescoping a ground was all you needed to
do to get transformer isolation.

These days transformers are too expensive and folks often consider them too
much of a source of possible audio degradation for everything to come with
transformer-isolation. So instead we have more iso boxes on the truck.

In the sixties, here in the US, if you knew someone that worked at the phone
company you could get them to bring you "repeat coils" which were used
for long distance circuit isolation and loading, and which were some of the
best audio transformers available at the time.

That sounds about right. I don't remember grounded outlets being very common
in the early 60s and don't remember any in the 50s. I still run into quite a
few
outlets with no ground even today. If you are lucky, the box will be
grounded and
you can just use an adapter. If the box isn't grounded, then I guess you
should
start looking for a water pipe.

In the US, you see a lot of those in homes, but not many left in commercial
locations. They turn up in old churches, though, as do things like DC
outlets...
--scott

 

[[email protected]]

Its not "usually" the sound system that creates the hazard
its the guitarist who has a groud fault or has snipped off the ground lug
from his power plug or is incorrectly using a edison adapter wo creates a
hazard condition
when his improperly grounded rig meets the right condition and a properly
grounded rig the current flows from his source(amp) out his guitar cable
into his guitar
now all he has to do is touch his strings and a mic stsand of a properly
grounded system toallow the current to complete its journey to ground
right through his body

"most" sound companies are accutly aware of proper electriacal protocol
most musicians are not
George

Exactly! I've worked around computers (not here in the USA) where a
ground was not available (a "special" adapter was used to remove the
ground... funny how those adapters are sold in stores), and it *hurts*
when you touch the chassis. 220V, too. We learned very quickly to
shut down the computers before plugging/unplugging devices, to avoid
pain.

Even when plugging my laptop into the mains to charge it, I'd get an
unpleasant shock if I even touched the ground around the microphone
Line Out jack.

Oh, here in the USA, the government really CARES about us! haha

Michael

 

[David McCall]

In the US, you see a lot of those in homes, but not many left in
commercial
locations. They turn up in old churches, though, as do things like DC
outlets...

DC outlets? I've heard tell, but I've never actually seen one.
Do you know if you can you still buy DC and steam in New York?
DC is great for studios and theater because the lamps don't sing.
The problem is, there isn't much other than old resistance dimmers
that will work with DC. Have you seen it in other places?

David

 

[ChairmanOfTheBored]

Snipped drivel...


Use wireless devices. Doh!

 

[UltimatePatriot]

next best bet, if you have to hold a wired mic, do not touch anything
else metal and do not have your feet wet.

Well, that pretty much rules out live stage performances in the rain
with a wired mic, eh?

Jeez!

 

[David McCall]

Exactly! I've worked around computers (not here in the USA) where a
ground was not available (a "special" adapter was used to remove the
ground... funny how those adapters are sold in stores), and it *hurts*
when you touch the chassis. 220V, too. We learned very quickly to
shut down the computers before plugging/unplugging devices, to avoid
pain.

In the US, I've seen 2 types of adapters.

One has a 3 pronged outlet with a 2 prong plug and aw ground wire
that is intended to be connected to the screw that holds the plate on.
Assuming that there is a metal box, and it is grounded (big assumptions).
If everything goes as to plan, the 3 pronged outlet should then be fine.
The advantage of the wire is that you can use one in each outlet.
Some people just cut off the wires and ignore the ground (bad plan).

The other style is the same thing except with a spade attached directly
to the plug in such a position that it can be connected directly to the
screw to provide a ground and it locks the adapter onto the outlet
making it more stable. You can only use one on a duplex outlet.

If used correctly, these are fine tools, but using them to lift the ground
is not allowed.

Even when plugging my laptop into the mains to charge it, I'd get an
unpleasant shock if I even touched the ground around the microphone
Line Out jack.

That isn't a situation that you should have to put up with.
Typically a laptop floats and isn't directly connected to ground.
There is probably something connected to it that isn't wired correctly,
or has some other fault. A while back, the RF cable for the cable TV
had quite a bit of kick when referenced to a water pipe ground.
We have fiber running directly to the side of the house now.
It is no longer an issue

Oh, here in the USA, the government really CARES about us! haha

They try, but you have to remember that some of "us" are retailers and
manufactures may have a different slant on what caring should be.
Sometimes they have more pull than you or I.

David

 

[Phil Allison]

"Christian Marg"

Would you care to tell us why instead of insulting the original poster
(which, in my opinion, is very unprofessional, as is "SHOUTING" in a
news posting)?

Maybe if you'd explain the danger of using a class 2 item, someone would
listen to you?

** You have not read what I wrote & you do not know what an utter PITA
Bloggs is.

Try reading the user instructions and warnings for a class 2 audio
appliance.

Try explaining how a WET class 2 item of sound gear is still safe to
se - go on.





....... Phil

 

[Scott Dorsey]

DC outlets? I've heard tell, but I've never actually seen one.
Do you know if you can you still buy DC and steam in New York?

NYC still had DC mains available until about a decade ago, when Con Edison
finally managed to install rectifier stacks running off three-phase at
the last of the DC customers. Most of them were folks using DC for elevator
service.

However, because of the leftover DC infrastructure, you will still see places
with DC power panels, operated off a rectifier, and with outlets off the DC
panel.

DC is great for studios and theater because the lamps don't sing.
The problem is, there isn't much other than old resistance dimmers
that will work with DC. Have you seen it in other places?

It still turns up in some larger cities with very old infrastructure. Here
you're more likely to see DC elevator motors with a motor-generator set to
provide the DC for them, but up in Richmond, VA. there is a church with a
fancy speed control system on their organ that was originally hooked to DC
mains and today is run off a rectifier stack. There are probably a lot of
those around.
--scott

 

[Paul Hovnanian P.E.]

Its quite dangerous. I think Spinal Tap lost a couple of drummers to
various electrocution incidents.