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Hugh RobjohnsAdministrator
SOS Technical Editor


Reged: 25/07/03
Posts: 21689
Loc: Worcestershire
Re: Well, yeah, again, electric shocks from mics !!
      17/10/09 11:32 AM
Yes, you need to be very logical and thorough when trying to track down a potential satefty earth problem like this.

There are lots of earth interconnections between the wall socket and the guitar, and every single one has to be good to be safe... so work through carefully and logically fromt he wall socket.

Start with a mains plug tester, as recommended above to check the wall socket(s) and do that at every single venue you use every single time you use it. I lost count years ago of how many tims I've found duff, unsafe sockets in public venues.

If the socket is safe and properly earth bonded, then work through all your mains extension boards and extension cables. The first check -- and one you should do everytime you pack and unpack you gear is a visual one, looking for cracks, cuts or crushes to the cable or any damage to the plugs of sockets -- any sign of physical damage requires careful investigation before use.

You can test the extension cables and boards with a multimeter but a quick and easy way is to use the mains socket tester again by plugging the extension cable of distribution board into the wall socket and then plugging the tester into each socket on the board or cable to check they are all okay. It is possible for individual sockets in extension boards to fail too...

If all the mains distribution stuff tests fine, then you'll need to move on to the IEC mains cables or the equipment itself if it uses captive mains leads. This is where you'll need to use a multimeter with a resistance or continuity mode. Don't plug the IEC leads into the mains -- instead put one probe onto the large mains plug earth pin and the other into the offset central earth receptacle on the IEC socket. You should get a reading of zero ohms or 100% continuity.

If it's a captive cable, then check between the mains plug earth pin and the metalwork on the equipment -- unless the label has the double-insulated symbol (a box within a box), in which case you won't get any continuity at all, by design.

Static shocks can be unsettling but are rarely any real problem and perversly do indicate that the system is probably properly earthed!

One way to determine whether you have a serious safety earth problem or just static shocks is to find out if the shock happens constantly or just briefly now and again.

A safety earth problem will mean that every single time someone bridges between something properly earthed (usually the mic) and the faulty part of the system (usually the guitar amp), they will get a shock (or, hopefully, trip the RCD!) and that the shock continues for as long as they are in contact (or until the RCD trips).

If it's a static shock, the first time they touch anything earthed they will discharge themselves and feel the brief moment of shock but thereafter they won't feel anything while they remain in contact. And if they touch it again a few moments later they won't feel a second shock either.

Only after they've shuffled around on the carpet or danced about to recharge their clothes will they build up their own static potential enough to feel a shock when discharging again through something earthed.

Hugh

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* Well, yeah, again, electric shocks from mics !! ghc 06/02/08 06:21 AM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   13/08/13 07:24 PM
. * Re: Well, yeah, again, electric shocks from mics !! Bass Growler   05/05/13 01:34 PM
. * Re: Well, yeah, again, electric shocks from mics !! ef37a   05/05/13 06:07 AM
. * Re: Well, yeah, again, electric shocks from mics !! Bass Growler   04/05/13 08:04 PM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   04/05/13 09:39 PM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   30/04/13 07:59 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   30/04/13 09:05 PM
. * Re: Well, yeah, again, electric shocks from mics !! witzendoz   29/04/13 07:12 AM
. * Re: Well, yeah, again, electric shocks from mics !! JonSSH   14/04/13 01:52 PM
. * Re: Well, yeah, again, electric shocks from mics !! dubbmann   02/08/12 08:54 PM
. * Re: Well, yeah, again, electric shocks from mics !! Raphbass   02/08/12 05:08 PM
. * Re: Well, yeah, again, electric shocks from mics !! dubbmann   31/07/12 05:15 PM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   31/07/12 10:56 PM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   02/08/12 11:50 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   02/08/12 12:46 PM
. * Re: Well, yeah, again, electric shocks from mics !! dubbmann   02/08/12 08:58 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   31/07/12 06:12 PM
. * Re: Well, yeah, again, electric shocks from mics !! Raphbass   31/07/12 11:51 AM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   31/07/12 12:34 PM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   31/07/12 12:30 PM
. * Re: Well, yeah, again, electric shocks from mics !! Raphbass   31/07/12 09:40 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   31/07/12 11:18 AM
. * Re: Well, yeah, again, electric shocks from mics !! Raphbass   30/07/12 06:44 PM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   30/07/12 10:45 PM
. * Re: Well, yeah, again, electric shocks from mics !! Raphbass   29/07/12 11:30 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   30/07/12 09:37 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   30/07/12 01:27 AM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   11/07/12 10:30 PM
. * Re: Well, yeah, again, electric shocks from mics !! Raphbass   11/07/12 11:08 AM
. * Re: Well, yeah, again, electric shocks from mics !! Dave Gate   11/07/12 12:08 PM
. * Re: Well, yeah, again, electric shocks from mics !! Raphbass   11/07/12 10:58 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   11/07/12 11:18 AM
. * Re: Well, yeah, again, electric shocks from mics !! Raphbass   16/07/12 05:28 PM
. * Re: Well, yeah, again, electric shocks from mics !! Dave Gate   21/06/12 09:47 AM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   21/06/12 11:08 AM
. * Re: Well, yeah, again, electric shocks from mics !! Dave Gate   21/06/12 11:13 AM
. * Re: Well, yeah, again, electric shocks from mics !! Dave Gate   20/06/12 03:24 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   21/06/12 09:21 AM
. * Re: Well, yeah, again, electric shocks from mics !! Jorge   20/06/12 02:17 PM
. * Re: Well, yeah, again, electric shocks from mics !! Dave Gate   20/06/12 09:32 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   20/06/12 02:19 PM
. * Re: Well, yeah, again, electric shocks from mics !! Jorge   20/06/12 07:45 AM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   20/06/12 08:39 AM
. * Re: Well, yeah, again, electric shocks from mics !! Gary_W   20/06/12 06:33 AM
. * Re: Well, yeah, again, electric shocks from mics !! Gary_W   19/06/12 12:20 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   19/06/12 02:36 PM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   19/06/12 01:07 PM
. * Re: Well, yeah, again, electric shocks from mics !! Gary_W   19/06/12 07:40 AM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   19/06/12 09:05 AM
. * Re: Well, yeah, again, electric shocks from mics !! Gary_W   18/06/12 07:23 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   18/06/12 08:59 PM
. * Re: Well, yeah, again, electric shocks from mics !! Gary_W   18/06/12 01:34 PM
. * Re: Well, yeah, again, electric shocks from mics !! TSH-Tim   30/10/11 09:37 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   31/10/11 01:20 PM
. * Re: Well, yeah, again, electric shocks from mics !! martin randle   30/10/11 09:19 PM
. * Re: Well, yeah, again, electric shocks from mics !! Lalala Music   26/07/10 08:42 AM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   27/07/10 07:24 AM
. * Re: Well, yeah, again, electric shocks from mics !! plodsmeade   20/05/10 03:49 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   21/05/10 08:15 AM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   23/05/10 10:10 AM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   20/05/10 09:24 PM
. * Re: Well, yeah, again, electric shocks from mics !! adamb1026   13/01/10 01:36 PM
. * Re: Well, yeah, again, electric shocks from mics !! chris...   02/01/10 05:06 PM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   02/01/10 06:20 PM
. * Re: Well, yeah, again, electric shocks from mics !! chris...   02/01/10 06:42 PM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   02/01/10 06:56 PM
. * Re: Well, yeah, again, electric shocks from mics !! chris...   02/01/10 07:13 PM
. * Re: Well, yeah, again, electric shocks from mics !! adamb1026   13/10/09 06:52 PM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   17/10/09 10:36 AM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   17/10/09 11:32 AM
. * Re: Well, yeah, again, electric shocks from mics !! the muppet   14/12/09 03:27 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   14/12/09 10:59 PM
. * Re: Well, yeah, again, electric shocks from mics !! feline1   15/12/09 11:37 AM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   14/12/09 05:31 PM
. * Re: Well, yeah, again, electric shocks from mics !! the muppet   14/12/09 10:46 PM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   06/10/09 09:13 PM
. * Re: Well, yeah, again, electric shocks from mics !! Mike Stranks   06/10/09 01:17 PM
. * Re: Well, yeah, again, electric shocks from mics !! TheChorltonWheelie   14/12/09 06:05 PM
. * Re: Well, yeah, again, electric shocks from mics !! adamb1026   08/10/09 12:19 PM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   09/10/09 11:30 PM
. * Re: Well, yeah, again, electric shocks from mics !! adamb1026   06/10/09 11:24 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   06/10/09 12:59 PM
. * Re: Well, yeah, again, electric shocks from mics !! adamb1026   05/10/09 09:54 PM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   06/10/09 09:35 AM
. * Re: Well, yeah, again, electric shocks from mics !! adamb1026   06/10/09 10:55 AM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   06/10/09 11:14 AM
. * Re: Well, yeah, again, electric shocks from mics !! Mike Stranks   06/10/09 08:44 AM
. * Re: Well, yeah, again, electric shocks from mics !! turbodave   02/08/09 09:07 AM
. * Re: Well, yeah, again, electric shocks from mics !! IvanSC   02/08/09 07:33 AM
. * Re: Well, yeah, again, electric shocks from mics !! Stewart Newlands   01/08/09 05:51 PM
. * Re: Well, yeah, again, electric shocks from mics !! Ian Savage   11/05/09 10:46 PM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   09/07/09 07:43 AM
. * Re: Well, yeah, again, electric shocks from mics !! eggle5   27/07/09 11:34 PM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   11/05/09 07:06 PM
. * Re: Well, yeah, again, electric shocks from mics !! Eon   11/05/09 04:41 PM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   11/05/09 04:54 PM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   11/05/09 05:12 PM
. * Re: Well, yeah, again, electric shocks from mics !! Steven Montgomery (Monty)   02/11/08 09:53 PM
. * Re: Well, yeah, again, electric shocks from mics !! Mattmvb   05/10/08 10:37 PM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   08/10/08 04:48 AM
. * Re: Well, yeah, again, electric shocks from mics !! Mattmvb   10/10/08 12:24 AM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   10/10/08 08:29 AM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   12/10/08 10:04 AM
. * Re: Well, yeah, again, electric shocks from mics !! thatsrightmynameisjohn   05/10/08 09:45 PM
. * Re: Well, yeah, again, electric shocks from mics !! thatsrightmynameisjohn   05/10/08 08:12 PM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   05/10/08 09:09 PM
. * Re: Well, yeah, again, electric shocks from mics !! Statick   05/10/08 05:41 PM
. * Re: Well, yeah, again, electric shocks from mics !! damoore   24/08/10 01:03 AM
. * Re: Well, yeah, again, electric shocks from mics !! Paul Soundscape   05/10/08 02:43 PM
. * Re: Well, yeah, again, electric shocks from mics !! thatsrightmynameisjohn   05/10/08 01:10 PM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   05/10/08 02:09 PM
. * Re: Well, yeah, again, electric shocks from mics !! IvanSC   08/09/08 07:10 AM
. * Re: Well, yeah, again, electric shocks from mics !! ef37a   26/07/08 01:31 PM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   26/07/08 03:06 PM
. * Re: Well, yeah, again, electric shocks from mics !! ef37a   26/07/08 12:58 PM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   26/07/08 01:18 PM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   26/07/08 12:31 PM
. * Re: Well, yeah, again, electric shocks from mics !! ef37a   26/07/08 11:41 AM
. * Re: Well, yeah, again, electric shocks from mics !! ef37a   26/07/08 05:12 AM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   26/07/08 10:29 AM
. * Re: Well, yeah, again, electric shocks from mics !! jbk   07/05/08 09:21 AM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   07/05/08 09:30 PM
. * Re: Well, yeah, again, electric shocks from mics !! jbk   08/05/08 06:51 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   08/05/08 07:05 AM
. * Re: Well, yeah, again, electric shocks from mics !! Stewart Newlands   16/04/08 11:27 PM
. * Re: Well, yeah, again, electric shocks from mics !! wigli   14/04/08 11:36 PM
. * Re: Well, yeah, again, electric shocks from mics !! Stewart Newlands   13/04/08 12:38 PM
. * Re: Well, yeah, again, electric shocks from mics !! Mattmvb   16/04/08 04:20 AM
. * Re: Well, yeah, again, electric shocks from mics !! Roidster   17/04/08 05:28 AM
. * Re: Well, yeah, again, electric shocks from mics !! Roidster   14/04/08 11:11 PM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   15/04/08 04:54 AM
. * Re: Well, yeah, again, electric shocks from mics !! Stewart Newlands   27/03/08 07:55 PM
. * Re: Well, yeah, again, electric shocks from mics !! Dale Campbell   11/02/08 08:29 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   12/02/08 10:58 AM
. * Re: Well, yeah, again, electric shocks from mics !! The muso   11/02/08 04:11 PM
. * Re: Well, yeah, again, electric shocks from mics !! PeteJ   11/02/08 10:57 AM
. * Re: Well, yeah, again, electric shocks from mics !! hifistud2   11/02/08 02:11 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   11/02/08 11:24 AM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   11/02/08 12:51 PM
. * Re: Well, yeah, again, electric shocks from mics !! Grim Audière   09/02/08 05:06 PM
. * Re: Well, yeah, again, electric shocks from mics !! The muso   11/02/08 03:14 PM
. * Re: Well, yeah, again, electric shocks from mics !! PeteJ   08/02/08 07:23 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   09/02/08 10:48 AM
. * Re: Well, yeah, again, electric shocks from mics !! revbobuk   01/04/08 05:22 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   01/04/08 07:32 PM
. * Re: Well, yeah, again, electric shocks from mics !! hifistud2   09/02/08 12:31 PM
. * Re: Well, yeah, again, electric shocks from mics !! The muso   09/02/08 11:19 AM
. * Re: Well, yeah, again, electric shocks from mics !! PeteJ   08/02/08 05:15 PM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   08/02/08 03:29 PM
. * Re: Well, yeah, again, electric shocks from mics !! The muso   08/02/08 03:54 PM
. * Re: Well, yeah, again, electric shocks from mics !! Sylle   08/02/08 11:14 AM
. * Re: Well, yeah, again, electric shocks from mics !! mpostor   08/02/08 01:39 PM
. * Re: Well, yeah, again, electric shocks from mics !! PeteJ   08/02/08 11:05 AM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   08/02/08 05:25 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   08/02/08 10:16 AM
. * Re: Well, yeah, again, electric shocks from mics !! The muso   08/02/08 10:19 AM
. * Re: Well, yeah, again, electric shocks from mics !! feline1   07/02/08 10:56 AM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   07/02/08 11:12 AM
. * Re: Well, yeah, again, electric shocks from mics !! feline1   07/02/08 11:59 AM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   07/02/08 12:01 PM
. * Re: Well, yeah, again, electric shocks from mics !! Paul Soundscape   07/02/08 11:23 AM
. * Re: Well, yeah, again, electric shocks from mics !! Matt P   07/02/08 02:45 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   07/02/08 06:15 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   11/02/08 03:28 PM
. * Re: Well, yeah, again, electric shocks from mics !! Nathan   07/02/08 10:44 AM
. * Re: Well, yeah, again, electric shocks from mics !! chris...   08/02/08 01:07 AM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   07/02/08 01:44 AM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   07/02/08 06:13 AM
. * Re: Well, yeah, again, electric shocks from mics !! Paul Soundscape   06/02/08 10:06 PM
. * Re: Well, yeah, again, electric shocks from mics !! DingoDave   06/02/08 09:36 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   07/02/08 02:05 AM
. * Re: Well, yeah, again, electric shocks from mics !! Paul Soundscape   06/02/08 07:14 PM
. * Re: Well, yeah, again, electric shocks from mics !! seablade   07/02/08 01:18 AM
. * Re: Well, yeah, again, electric shocks from mics !! jamaicanDave   06/02/08 04:41 PM
. * Re: Well, yeah, again, electric shocks from mics !! Paul Soundscape   06/02/08 02:14 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   06/02/08 03:47 PM
. * Re: Well, yeah, again, electric shocks from mics !! CS70   06/04/13 08:59 AM
. * Re: Well, yeah, again, electric shocks from mics !! plodsmeade   19/05/10 05:19 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   19/05/10 08:39 PM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   19/05/10 06:03 PM
. * Re: Well, yeah, again, electric shocks from mics !! Paul Soundscape   06/02/08 12:57 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   06/02/08 01:24 PM
. * Re: Well, yeah, again, electric shocks from mics !! Paul Soundscape   06/02/08 10:10 AM
. * Re: Well, yeah, again, electric shocks from mics !! dmills   06/02/08 06:40 PM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   06/02/08 10:41 AM
. * Re: Well, yeah, again, electric shocks from mics !! Sheriton   06/02/08 10:07 AM
. * Re: Well, yeah, again, electric shocks from mics !! Hugh RobjohnsAdministrator   06/02/08 09:24 AM

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