The HS executive do a leaflet on electrical safety for entertainers. You can download it here as PDF file:

HSE executive PDF on electrical safety for entertainers

Note sure it adds much to the discussion, but it's a useful reminder.

Thanks all
Turns out she had three layers of nylon on under that dress!... hang on... make that four

valentine's day is coming... buy her some silk!

Hugh

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Technical Editor, Sound On Sound

Off Topic, Off Topic ...pheeeeep!



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planet nine
lincoln, uk.

Yerst... it all needs takihng off...

one layer at a time...

slowly...


video please!!!!

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[url=http://www.facebook.com/pages/hifi-studios/117322741632389[/url]

Quote Grim Audière:

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The HS executive do a leaflet on electrical safety for entertainers. You can download it here as PDF file:

HSE executive PDF on electrical safety for entertainers

Note sure it adds much to the discussion, but it's a useful reminder.

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Good man.
Definately ON topic!

Quote seablade:

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Quote Matt P:

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I know it's been said a million times before, but surely we can all agree that this topic warrants being made a sticky.

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Yea at this rate, I gotta agree, something needs to be done to keep this perfectly visible, not sure if a sticky thread is the right answer or not. Maybe an FAQ section along the lines of Martin's computer FAQs? Ah well up for the mods/admins to decide not me.

Anyways to answer your other question I bought this kit for basic electrical analysis that I carry with me.

http://www.lowes.com/lowes/lkn?action=productDetail&productId=205783-7 2068-TK-30&lpage=none

I believe the socket tester in it wil check for a live/neutral reverse, but I will double check tomorrow. At the moment I need to get some sleep and don't feel like getting dressed to go out to the car to check.

Seablade

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For the record, yes mine does do a Hot/Neutral Reverse check. Cheap 20 buck kit got me a cheap multimeter, a socket tester, and voltage detector, not a bad deal to me.

Seablade

Good link here;

http://professional-sound.com/soundadvice/datadirectory/viewnews.cgi?id=11 91436814

I really do love my wireless setup as it puts several feet of air between me and electrocution

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Crazy guitar beating - www.myspace.com/dalecampbell

There is something to be said for that...

Hugh

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Technical Editor, Sound On Sound

For the new BS7909 code of practice (in draft now) it is recommended that (for small systems from 13A outlets etc) you check the sockets using at least a socket test device that includes an Earth loop indicator and you should not use any socket that has an earth loop above 500 ohms, something like this http://www.martindale-electric.co.uk/sockets.htm#ez150

You should also have an RCD, and you may need to bring this with you as some places still do not have them fitted.
see also the HSE publications: INDG247 - Electrical safety for entertainers http://www.hse.gov.uk/pubns/indg247.pdf
and GS50 Electrical safety at places of entertainment which is is for the venue.

Now (referring to a post up the page a bit, where Hugh seemed to be suggesting that mics and stands are earthed for safety reasons) that would be a first for me - did you really mean that mic. stands should/must be earthed? I don't think I've ever seen that. Mics, yes. But stands? How would you do that?

Edited by revbobuk (01/04/08 05:24 PM)

Quote revbobuk:

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Hugh seemed to be suggesting that mics and stands are earthed for safety reasons) that would be a first for me - did you really mean that mic. stands should/must be earthed? I don't think I've ever seen that. Mics, yes. But stands? How would you do that?

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I didn't mean to suggest that stands should or must be earthed. The metal body of mics are through the cable screen, obviosuly. Stands can become earthed because of contact with other earthed metalwork.

Performers usually get shocked becasue they are holding the guitars strings in one hand (which might be floating at half mains voltage or worse of the amp is missing it's protective earth), and then touch the mic (the body of which is earthed through the mic cable and mixer).

hugh

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Technical Editor, Sound On Sound

The venue must test socket outlets as a licence requirement in most cases. This is done formaly be electrical contractors or competent in house electrictians.

If sockets are not safe don't use them, walk away and if anyone hassels you remind them that electrical systems have to be safe as a requirement of the Electricity at work regulations 1989 under the HASAW act.

The IEE wiring regulations BS7671:2008 which now include temorary stuff for shows refer you to BS7909, which is being updated and is available in the 1998 form or as a draft 2008 version.

Both BS7671:2008 and the draft of BS7909:2008 recomend that the socket outlets are tested before use, for saftey particularly to check that the protective earth is continuious and that the resistence to ground is low enough to be effective in enableing the effective operating of protective devices.

I would as a minimum invest in a decent socket check plug with an indication of earth fault loop impedence.

More information about these things can be found at these links:

www.hse.gov.uk/electricity/socket1.htm
www.hse.gov.uk/pubns/indg247.pdf

http://www.martindale-electric.co.uk/sockets.htm#ez150

I am going to try to get permission to use section 5 of the proposed BS7909:2008 available as part of a free or low cost information sheet for lay electrical users.

well from my personal exprience,as a singer/guitar player
i found when getting a shock from a mic,usually come from a bad ground,due to plugs being in different wall sockets
and man it can hurt sometimes,my easy fix is,put my guitar
mixer and power amp all on the same wall socket,problem fixed
but this is really isn't a long term fix

there is bigger problem with the electrical in the house or building,some people call it dirty power,and could result
in a fire cause by an electrical problem,meaning the place could burn to the ground and you lose everything
and it might be good to have an electrical inspector
come in and check everything out

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Just a Musician

Did the venue have three phase power and if so was ALL the audio equipment plugged into the correct (ie. same ) phase?

Quote Roidster:

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well from my personal exprience,as a singer/guitar player
i found when getting a shock from a mic,usually come from a bad ground,due to plugs being in different wall sockets
and man it can hurt sometimes,my easy fix is,put my guitar
mixer and power amp all on the same wall socket,problem fixed
but this is really isn't a long term fix

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It is important to note, that if that socket has a faulty ground, this will not fix the real problem. Good grunds are important.

Quote:

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there is bigger problem with the electrical in the house or building,some people call it dirty power,and could result
in a fire cause by an electrical problem,meaning the place could burn to the ground and you lose everything
and it might be good to have an electrical inspector
come in and check everything out

---

What most people call "Dirty power" is actually a bit different. It ranges in definition, but in general it tends to fall into the category of under or over-voltage power coming from a bad source, or overly taxed distribution. I have also seen it refer to poorly isolated power, leading to similar problems as above, for instance an elevator motor starting up causing the sound system to get an under-voltage as it draws power.

Seablade

Many thanks for the info and links. This is something that's been on my mind recently, ever since I got a nasty shock from a standard lamp of all things - although I am very gratefull that it wasn't anything more than nasty, and that it was me not one of my customers. It was a lamp we move round quite often, and poor design meant that every time it got moved it rubbed a little more insulation off the live cable... (I know that's meandering a bit off topic but bear with me)

I run a small independent venue and regularly have the electrics checked out. However this incident has brought it home to me that something could go wrong 5 seconds after the electrician walks out of the door, and he may not be back for 6 months to check it out again.

This line was an eye opener for me:

Stewart Newlands Quote:

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If your socket tester cannot display the Earth Fault Loop Impedance, it should not be used to check whether a socket is adequately earthed and safe to use.

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I guess I'll have to upgrade to a more expensive tester - the cost is easily justified as you can't put a price on peoples lives.

Sadly, in my experience, this line isn't right:

Quote Stewart Newlands:

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The venue must test socket outlets as a licence requirement in most cases. This is done formaly be electrical contractors or competent in house electrictians.

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Unfortunatley I've never seen or heard of this being an actual licence requirement. For example, my own licence has several conditions pertaining to safety such as all fire routes must be kept clear and spills must be mopped up imediately, but naff all about electrics. There is a legal obligation that eveything must be safe, but too many operators look at their licence as being the be all and end all of their obligations. Also, since the changeover to the new licencing laws, I've had 2 "taskforce" visits, which basically means that police, licensing, environmental health and fire officers all turn up together to make sure you're within the letter of the law, but they've never even looked at the electrics! And I know that's the case in various friends venues as well.

Quote Stewart Newlands:

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If sockets are not safe don't use them, walk away and if anyone hassels you remind them that electrical systems have to be safe as a requirement of the Electricity at work regulations 1989 under the HASAW act.

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To be honest I'd recommend going one further than that and notifying the EHO (Environmental Health Officer) of the situation. There are a small minority of operators who don't give a damn, but if something goes wrong we all get tarred with the same brush.

Remember, YOU may have the chutzpah to walk away and cancel your gig, but there will be a lot of up'n'coming bands who will happily take that risk for a bit of exposure. That said, please speak to the management first, it could be a new problem and most of us are decent folk who really don't want to see a performer get electrocuted on stage!

Rant over!

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One is too many, two is about right, but three can never, ever, be enough

You can find more information about Electrical Saftey at www.7909.org.uk which will be listing all sorts of stuff regarding BS7909:2008 and BS7671:2008 and entertainment.

There may be some NVQs in this area at some point starting with a level 2, but it is some way off just now.

Quote Mattmvb:

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Many thanks for the info and links. This is something that's been on my mind recently, ever since I got a nasty shock from a standard lamp of all things - although I am very gratefull that it wasn't anything more than nasty, and that it was me not one of my customers. It was a lamp we move round quite often, and poor design meant that every time it got moved it rubbed a little more insulation off the live cable... (I know that's meandering a bit off topic but bear with me)

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this guy i knew,was living in a house,but it wasn't the lamp he was getting shocks from
everytime he used any light switch in the house,he would get a nasty shock
it had gotten to a point were he would use a stick to turn on and off the lights,in his house
finally they had gotten an electrical inspector in
he shut the hydro off at the pole and told them
every electical wire that ran through out the walls
floor and ceiling had to be replaced,before they would hook
the power back up
he said to them they were lucky there was never a electrical fire
this was an older house with original wiring,so over time the wires had deteriorated

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Just a Musician

If your under pressure to get your sound-check done you can try sticking a D.I. box between your guitar and the amp and plug the XLR cable from the D.I. into a stage box. This should solve the problem on the night and the show can go on.

Quote jbk:

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If your under pressure to get your sound-check done you can try sticking a D.I. box between your guitar and the amp and plug the XLR cable from the D.I. into a stage box.

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Um. Not convinced about that. The pass through output that goes from the DI to the amp doesn't usually offer any isolation so it won't electrically separate the guitar and (potentially dodgy) amp. Also, most guitar amps are mic'ed which doesn't present any electrical problems so I can't see why you'd want a DI feed instead...
Personally, if there's dangerous electrics on stage, the gig can wait until it's sorted. The show doesn't have to go on if it means putting lives at risk.

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There's nothing we can't face... Except for bunnies

This is if your getting shocks from the mic because the guitar is not properly grounded. you ground it with the XLR into the stage box. It's not a channel your going to use , so it's got nothing to do with the guitar being miced. It works, and always has done. It's not a permanent and far from ideal solution but as I pointed out the show must go on!

Quote jbk:

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...as I pointed out the show must go on!

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It takes me about 5 minutes to wire a new edison onto a plug over here. The show must go on, but not at a dangerous cost.

I will admit to being a bit sleep deprived, but at first glance your solution may work, by providing a path to ground with a lower potential, but it is addressing the symptom instead of the problem. Add this onto the fact that removing the shield in an audio cable is not an uncommon occurance to prevent ground loops in a safer way, and you are left with no path to ground except through the performer.

Fix the problem, not the symptom. Especially when it takes a couple of minutes at most, and ensures someone's safety.

Seablade

Wigi brought the matter up but can I reinforce his statement regarding phases please?

It might be very tempting if you run out of outlets to just run another extension to another room. There is NO guarantee that the room is on the same phase and thus the voltage stress on the equipment is greatly increased. Futhermore the earth path resistance will almost certainly be increased.

In older building that have been "knocked about" it is even possible that a socket at one end of the room has been "pinched" thru' a wall from another phase. AFAIK there is no easy, safe, cheap way to test for this so as Hugh says, run eveything from one outlet or those as close together as possible. You can pull nearly six kW from a 13A double, enough for any SOUND system surely!

Dave.

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#They did not listen, they are not listening still...Perhaps they never will?#

Quote ef37a:

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You can pull nearly six kW from a 13A double, enough for any SOUND system surely!

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No you can't! You're likely to start a fire if you try. With most twin outlets, the most you can draw is around 20A; they're not designed to be able to supply 13A from both outlets simultaneously. There are some designs out there that can do so safely but these are the exception rather than the rule.

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There's nothing we can't face... Except for bunnies

Thank you Sheriton. I was basing my figures on a ring I have just put in using 32A trips.

Are you saying the OUTLETS will burn, because the cable can surely stand 32A?

Dave.

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#They did not listen, they are not listening still...Perhaps they never will?#

The sockets themselves can overheat as they're not designed to be able to supply that much current. I believe it's the point where the cables are connected at the back that is the weakest link.

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There's nothing we can't face... Except for bunnies

Well, I was not suggesting a pair of 3kW heaters!

Shall we meet at a 5kW but not a continous load? 20A is not 5k I admit at 230V but we always get 240+ here and that is pretty close.

Our new premises run 250 most of the time and has hit 254 now and again!

Dave.

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#They did not listen, they are not listening still...Perhaps they never will?#

On the phase thing, I would note that running systems across multiple phases is actually NOT a problem (And is done routinely on largish gigs (32A TP+N is a much smaller and lighter cable then 63A SP)), there is 400 odd volts phase to phase sure, but as a minimum of 4 faults are required to end up with two bits of exposed metalwork being live to different phases (Two earth faults and two phase->case faults) this should be a completely negligible risk if your electrical maintenance regime is even halfways competent.

The large earth loop that can result from plugging into multiple locations can cause circulating currents in the screen connections, but as long as nothing has a pin one problem, and everything is balanced, that rarely causes hum (And if it does, just fix the gear already).

One thing to watch with ring mains is that you never know what else is connected to them (Think Ice makers!), but for a general bar gig I would probably be quite happy to run a PA off one, sound requires remarkably little RMS current (and it is that, not smallish short term peaks that causes problems). Lighting is of course another matter.

I would second the advice to get a good socket tester, and getting the local theatre sparks to PAT your gear for you occasionally is never a bad thing (Normally costs a few pints). Hell just opening up the plugs and tightening all the screws once a year goes a long way.

Regards, Dan.

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Audiophiles use phono leads because they are unbalanced people!

Ok Dan,

I take you point about phases. I based my warning on an experience at a factory where I was a general handyman. The power on one wall in the refrectory failed one hot afternoon and there were 3 snack chillers in there. I quickly ran in a couple of mains leads from the testroom outlets about 15mtr away the other side of a breezeblock wall.

I was roundly castigated the next day by the visiting sparks re phase dangers. I did think at the time that you would have to be bloody unlucky.....

Dave.

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#They did not listen, they are not listening still...Perhaps they never will?#

A long time ago there was a requirement in the 'wiring regulations' (BS 7671) to separate all sockets on different phases by 2M, but that was removed many years ago.

There are however still many site electricians that seem to be wedded to following this practise to the point of insisting on it.

I just had some 200 channels of lighting dimmer installed at work we did try to keep it to one phase per bar (not always successfully) on the grounds that it doesn't hurt and there is an outside chance that it may help some day, but it is not something to get overly worried about.

I do however try to keep all the backline on one phase as in my experience this tends to be where the really dodgy stuff turns up (And the venue often does not have easily applied control over it).

FWIW My amp racks (and fixed signal processing) are fed from a three phase supply locally broken down to give the required single phase feeds, are installed right next to the main dimmer racks (the location was convenient), and the whole thing is totally silent.

An awful lot of the time you get moans from sound types about buzz from dimmers it is more a reflection on the sound companies engineering then it is venue or lighting companies...

Regards, Dan.

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Audiophiles use phono leads because they are unbalanced people!

Just to breathe life into this sticky again, we nearly lost 3 more to electric shock at the weekend.

Kim Rew, Lee Cave Berry & Ted Koehurst were playing a gig with a dodgy 3 phase installation & lost all 3 amplifiers, plus Ted got well and truly zapped.
No dead bodies, but how close do you need to get?
The worrying thing is that the amps worked for one set before frying (and predictably in at least one case shorting to the input jack, which was earthed to the chassis)
Ths was not a bad earth, this was incorrect voltage (440)which makes it even scarier.
I don`t have all the details yet but will try to post once I get in touch with one of them.

RDF`s don`t always get everything folks - especially if you are playing outdoor events/festivals, it pays to carry a good mains tester as well as your own individual RDF device.
Cheap life insurance.

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Me? But I`m such a loveable old bugger!

Hi, I've just been reading through this thread and despite not understnading anything, it worries me.

I've had a few gigs where I have been getting painful shocks off the mic when I touch it to sing (I play guitar and sing).

I don't know anything about electronics so would anyone be able to explain to me (in simpler terms) what I would have to do/buy to ensure that both me and my bandmates are safe both at gigs and at practice?

Thanks very much
Adam

The first thing I'd suggest is to get someone electrically competent to have a look at your guitar amp. The main cause of experiencing a potential difference between your mouth and the mic is that the earth in the guitar amp isn't doing its job which causes the guitar strings to float up to 110v. You won't notice this until you touch something earthed like a microphone.
1st thing to check is inside the mains plug - make sure the earth wire is well & truly connected to the earth pin.

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There's nothing we can't face... Except for bunnies

a socket tester is also a useful tool,
check every socket you plug your gear into to make sure its wired properly and is earthed

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Live Sound and Studio Engineer

on the second night of our most recent tour, the singer/guitarist got a nasty zap off her mic during soundcheck.

turned out it was the 4-way at fault (the earth lead had come loose from the plug), but anyway the next day i went and bought a simple £10 mains tester. we used it before every show for the remainder of the tour, and found several instances of missing earth and live/neutral reversed, but in all cases it was extension leads that were at fault - the wall sockets themselves were all fine.

so the moral is, i guess, test all the extensions as well, especially if it's venue-owned gear and not your own.

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Statick Audio

Thanks for the advice, I've got a couple of mates who are sparkies so I'll get one of them over to check my gear out.
Can someone link me to a good socket tester that will test for everything and is easy to use?

I tried google but I don't really know what to look for..

Cheers

This one should be a good starting point.

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There's nothing we can't face... Except for bunnies

Cheers mate