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Gig Safety - RCD, Residual Current Devices.


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I have some village fete type gigs over the summer and no doubt the power supply will be shocking (ahem) at some of them.

 

Can anyone recommend a good RCD?

 

(I've already got EMG pickups - so no ground wire to the bridge, and I'm thinking about taking my wireless as well even though the stage sizes won't need it)

 

ta

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45 minutes ago, Rich said:

 

 

Noted.

 

I've ordered a couple of those, thank you. There's only me and an electric piano plugged in (rest is drums and a lot of horns and reeds) so hopefully that will do the job.

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Can I ask an idiot question here... I know there is the risk of shock, but what does it come from (electricity, obviously but in what circumstances?). I'm all for not being killed playing at a sh!tty charity festival or what have you so keen to know where the risk is and if one of these plug ins can help then I'll buy as many as we need for the band. Ta

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1 hour ago, uk_lefty said:

Can I ask an idiot question here... I know there is the risk of shock, but what does it come from (electricity, obviously but in what circumstances?). I'm all for not being killed playing at a sh!tty charity festival or what have you so keen to know where the risk is and if one of these plug ins can help then I'll buy as many as we need for the band. Ta

 

Electricity is supposed to come down one wire (the 'Live'...) and go back up the return wire (the 'Neutral'...). All is well with the world. Then comes the Incident, whereby a Fault somewhere allows the electricity to get to something other than the Neutral wire (a short-circuit, a breakdown in insulation, ingress of liquids, dog chewed a cable... The list is long...). In such a case, the sum of electricity going down the Neutral wire will be less than that arriving from the Live wire, the difference going, perhaps, through the body of a poor unsuspecting Musician, thanks to the Fault. This situation is what the 'Plug Thingy' (a technical term...) detects. Any imbalance above a certain 'safe' level between Live and Neutral is deemed to be potentially life-threatening (indeed, it is...), and the Thingy cuts the juice until the Fault is located and corrected. B|
There, that's the 'simple' explanation. Is it sufficient..? :friends:

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Good thread - I read it and had ordered from the link before I'd finished it! RCD is now waiting at the local Screwfix ready for me to collect.

 

Remembering to use it, though, is a different matter!

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2 hours ago, FinnDave said:

Remembering to use it, though, is a different matter!

This might help - round the back of a wedding venue several years ago. I needed some air after setting up and found the power supply for the whole marquee with the grey cloth wrapped around the connection. My RCD was already plugged in. 😲

P1040482-2.jpg.3d7983561b859f70a4b263d1185efa7d.jpg

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I always carry a ring main tester (a few quid from you local ToolFix ScrewStation). Plug it into a socket and if all 3 lights come on you’re golden. Anything else indicates a fault, most commonly live and neutral reversed (be afraid) or no earth (be very afraid). In those (rare) situations the venue should be made aware as it their potentially lethal problem to fix.

Edited by JapanAxe
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4 minutes ago, JapanAxe said:

I always carry a ring main tester (a few quid from you local ToolFix ScrewStation). Plug it into a socket and if all 3 lights come on you’re golden. Anything else indicates a fault, most commonly live and neutral reversed (be afraid) or no earth (be very afraid). In those (rare) situations the venue should be made aware as it their potentially lethal problem to fix.

 

Good idea!

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2 hours ago, JapanAxe said:

I always carry a ring main tester (a few quid from you local ToolFix ScrewStation). Plug it into a socket and if all 3 lights come on you’re golden. Anything else indicates a fault, most commonly live and neutral reversed (be afraid) or no earth (be very afraid). In those (rare) situations the venue should be made aware as it their potentially lethal problem to fix.

I have had one of these in my plugboard for decades and so far it's not detected any faults. I do check it fairly regularly by plugging in at home just to be sure it's working ok.

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2 hours ago, jazzyvee said:

I have had one of these in my plugboard for decades and so far it's not detected any faults. I do check it fairly regularly by plugging in at home just to be sure it's working ok.

 

In 30 years of using it I have come across a no-earth situations 3 times. In 2 of these the solution was to run an extension from a good socket. In the last it was an outdoor stage so I got the organisers to create an earth by running a wire form an earth pin plugged into one of our socket strips, to a lamp iron driven into moistened ground next to the stage. It worked and the show went on.

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Picked up my RCD from screw fix this morning. I told my wife to look after the receipt so that if I am electrocuted on stage she can get the £7.95 back. She wasn't amused!

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11 minutes ago, FinnDave said:

Picked up my RCD from screw fix this morning. I told my wife to look after the receipt so that if I am electrocuted on stage she can get the £7.95 back. She wasn't amused!

See Dave thats why your so popular, always thinking of others :D

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Electrician here...

 

RCDs are very useful @Dad3353's explanantion was on the money.

 

However, check to see if the circuit you are using already has an RCD built in to the fuseboard/consumer unit.  Two RCDs in the same circuit can cause nuisance tripping so only use the plug in RCDs when there is no pre existing RCD or RCBO (google that) at the fuseboard

 

The plug in socket testers are useful.  I use them as a guide to inform me whether anything is wrong.  Left and middle light glowing green and the 3rd/right hand light off means all is hunky dory (probably).  Anything else and the circuit needs to be investigated.

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It is also possible that for a small generator connected to a 13A distribution board for you to plug into,  it may have no terminal to connect it to earth. Similarly, if your gig is under a gazebo in a tarmac carpark, or on a concrete slab, you will not be able to hammer an earth spike into the ground.

Provided that the generator is local, and not feeding any other areas, it is a floating mains system, and will require two simultaneous faults to become dangerous - the first to earth it, and the second to give you a live part to touch, allowing current to flow through you to earth.

'Simple' circuits like that will not work with some plugtop RCDs since they will not switch on unless they detect a connection between neutral and earth, which is the norm in most houses.

As others have said, a generator feeding multiple areas should be earthed, and/or may have been earthed at any of those areas, and therefore only needs one fault to allow current to flow through you to earth. That is where the RCD is helpful.

David

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4 hours ago, BillyBass said:

Two RCDs in the same circuit can cause nuisance tripping

That may well be the reason why the supply in the pub I was playing a few years ago kept cutting out. The whole pub, three times. 😀 I figured out it was something to do with my extension (with and RCD attached) and used another but I was Mr Popular with the staff that night.  

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1 hour ago, Franticsmurf said:

That may well be the reason why the supply in the pub I was playing a few years ago kept cutting out. The whole pub, three times. 😀 I figured out it was something to do with my extension (with and RCD attached) and used another but I was Mr Popular with the staff that night.  

You may have got the blame that night but if the whole pub went then that means they have an RCD as the main switch on their fuseboard.  Asking for trouble!

RCDs are sensitive, consequently it is not advised to have one as the main switch of the board of somewhere like a pub or a house, there should be at least 2 RCDs,  or, preferably, an individual RCD for each circuit (called RCBOs).

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