Rehearsal room/stage electrical safety gear

[Beedster]

There's a current thread re some small shocks a singer is getting from a mic and it prompted me to think a bit more about safety. Although I think I'm careful around this stuff, I'm probably not as careful as I could/should be - especially looking at the state of sockets and cables in some venues - so I'm keen to know what devices folks use to reduce the chances of electricity going where we don't want it? 

[Franticsmurf]

If I don't know the venue, if I'm playing outside or if anything looks dodgy I use an RCD circuit breaker on my main power block. I went wireless years ago to give me some isolation from my backline. In my current band we have two working electricians, so they are always on the case regarding venue electrics.

[dudewheresmybass]

Part of the reason why I'm totally wireless. 

I've played enough venues with dodgy electrics to protect myself.

These days - fortunately - there seem to be less iffy venues (at least around the south east)

But I always carry an RCD as well JIC

[Burns-bass]

We always take plug testers to gigs after a dodgy connection.

 

Cost £15 or so and easy to stick in the gig box. 
 

https://www.screwfix.com/c/tools/socket-testers/cat7910008

[ossyrocks]

11 minutes ago, Burns-bass said:

We always take plug testers to gigs after a dodgy connection.

 

Cost £15 or so and easy to stick in the gig box. 
 

https://www.screwfix.com/c/tools/socket-testers/cat7910008

There's a socket tester in that link for £5.00. Is that the kind of thing you mean, if so, I'll get one?

 

[Burns-bass]

33 minutes ago, ossyrocks said:

There's a socket tester in that link for £5.00. Is that the kind of thing you mean, if so, I'll get one?

 

 

Yes, that's what I have. It provides a check of each plug and tells you if it's correctly wired and grounded or not. 

 

I'm no electrician (and the guys who put in the cabling also have an RCD) but I do it every venue I go to now to ensure me and my equipment will be OK.

 

One of the singers in my band got a shock one gig and we ended it early as we had no faith in the safety of the venue. After that, I didn't want to take any risks.

 

 

[casapete]

Think I’ve mentioned this before but when a venue asks to see any PAT certificates for your gear,

then you also have the right to see their up to date EIC (Electrical Installation Certificate).

If it’s a temporary event then the organiser should have evidence of the electrical supply 

completed to BS7909 standards. 

[42Hz]

Aren't residual current breakers required for any legal installation ?

(General question)

Do they exist as simple carry along / plugin devices ?

[godathunder]

15 minutes ago, 42Hz said:

Aren't residual current breakers required for any legal installation ?

(General question)

Do they exist as simple carry along / plugin devices ?

Yes, and cars arent allowed to run you over on a zebra crossing but it's still wise to look left and right before you cross.............. (less snarkily, yes, theyve been required for over 20 years but you'll still encounter the odd legacy system out there so its a good idea to carry your own. Be prepared and all that dib dib dib)

 

Yes, 13a plug in rcds exist - they cost about the same as a couple of pints

https://www.screwfix.com/p/masterplug-13a-fused-plug-in-active-rcd-plug/44855

[Huge Hands]

In my experience as a former sound engineer, these shocks are caused by potential differences in the earths between your mixer and your PA, backline amps etc.   If it is a small system, and everything is plugged into the same socket, it is usually fine.

 

The problem comes when you have your on-stage gear plugged into one socket/ring main, and your mixer out front in another and they don't have a fully shared resistance free common earth.  Any potential difference then takes the fastest route to earth via you and your mouth when you get close enough to the mic, especially if you're holding a guitar.

 

The best way is to take a marked up XLR cable for the mic with the ground (pin 1) disconnected at one end. This will act as a ground lift (like the switch on a DI box) and should stop the belts in the mouth.   Obviously this may cause the mic feed to be noisier in certain venues as you've removed the ground, but that could be the better of the two evils. 

 

I remember doing this about 25 years ago with the band Nine Below Zero at the venue I worked at.  The venue was desperate to open but the lead singer was still soundchecking, strumming his guitar and getting shocks.  I got one of the crew to open up his XLR, cut the connection to pin one, tape it up and put it back together in front of him.   He stood there and watched in disbelief thinking we were idiots.

 

He put the lead back together just as the venue manager decided to close the curtains and let everyone in.   As the crowd ran in to get their positions, the lead singer strummed behind the curtains with just the monitors on (that were still loud in the venue) and went "Hey mate - either that was lucky guess or you're a f***ing genius!" 

 

We kept that lead but hardly ever had complaints that would mean we needed to use it again - I assume it may have been something to do with his amp, perhaps earthing him faster through the mic, rather than the other way round.

Edited 9 hours ago by Huge Hands

[TimR]

4 hours ago, Huge Hands said:

In my experience as a former sound engineer, these shocks are caused by potential differences in the earths between your mixer and your PA, backline amps etc.   If it is a small system, and everything is plugged into the same socket, it is usually fine.

 

The shocks I've recieved are where someone has removed an earth to prevent a ground loop hum. 

 

Eg. Guitar amp (hand)  to Microphone (mouth) where the Pa Earth has been removed to prevent hum from Keys. 

 

 

Edited 4 hours ago by TimR

[Huge Hands]

Hi Tim,

 

The point of what I suggested is that you isolate the ground to the mic itself.    I assume in the example you quoted, someone has lifted the ground elsewhere, so the mic is still connected to the PA ground via the cable shield, and therefore any potential in the PA earth plane is earthed through your mouth and guitar/amp.  I think this is more likely than it travelling from your guitar earth to the PA earth if you're saying the ground was removed? 

 

If you remove the shield from the mic, the casing of the mic should not be connected to earth and therefore stop you getting belts. 

 

Maybe I have misunderstood what you meant.

[TimR]

8 hours ago, Huge Hands said:

I assume it may have been something to do with his amp, perhaps earthing him faster through the mic, rather than the other way round.

 

Or a compelte lack of earth. 

 

If a venue has different ring voltages on the earth, that's not good and implies a problem with the ring earth somewhere. The earths in a building should be common.