John Sayers' Recording Studio Design Forum Archive

Hi!

I'm often getting electrical shocks in my studio - they don't seem to be statical.

Some Examples:

• Lips on Mic - Ouch!
  One hand on audio cable mass, the other hand on the Rack
  Hand on Computer Mass, Arm on Subwoofer's Metal Back

A phase-checker screwdriver lightens up on the Power Jack's mass (but that could also be inductive).

Here is an electrical plan of my Homestudio:
(blue=audio, black=220V ~ )



Are the cascaded Multi Power Plugs perhaps a reason for this problem?

Thanks!

PS: Sorry for the bad english, i hope you understand everything

http://en.wikipedia.org/wiki/Domestic_A ... nd_sockets

I believe your power connections are typically type F in this page (scroll down to verify this) it sounds to me like your ground system isn't working properly, or maybe you have some cables that don't continue the ground all the way through?

The "side clip" ground on this type plug can get bent so it doesn't make good contact. If you have access to an actual multi-meter, you should check to see that ALL your power plugs' ground clips are a good connection to your ACTUAL ground (usually a metal water pipe can be used for a ground reference for this test).

Let us know if this helps, getting shocked isn't fun and can be DEADLY.

Your English is at least as good as mine, and I write technical manuals as part of my job; no apologies necessary... Steve

Hi,
i finally found the time to answer this.

In Germany we use the plugs described in the document as Typ F, also Type E/F hyprid as well as the Europlug Type C for devices with isolated cases.

The important thing is that we use three wire connection with Phase (L), Neutral (N) and Ground (PE Potentialerder). Normally in a three wire system (as described) there is a connection between Neutral and Ground (Earth), so that in case of shortcut or connection to the devices case the fuse will be blown or the residual-current device (Fehlerstromschutzschalter FI in german) will open.

Now it is important to know how old your house is. In old installation the bridge between Neutral and Ground (N and PE) was done in the wall socket (klassische Nullung), in new installation (70s?) it is done at the mainfuse in the basement and the installation is done with three wire cables all over the house.

So the problem can be: Wrong connection in the house or socket, or a problem with your extension/multiplugs. Most problems i had with shocks was comming from faulty cables or extensions. (most in live PA systems, with rain etc.)

So please do this:

If you have someone who is a learned electrician (gelernter Elektriker), ask him.

Disconnect the first plug from the wall socket and get the wall socket ground checked with your phasechecker, but better with a volt-meter or duspol (Two-wire-phase-meter). If you have a voltmeter, check if you get 230 Volts from Phase to Neutral, and also from Phase to Ground. If you do not get the 230 Volts from Phase to Ground, the grounding is wrong. Attention: If you do this with the duspol instead of a volt-meter, the FI will open!

Again: If you have someone who is a learned electrician (gelernter Elektriker), ask him.

If you detect a problem with wall socket, get someone to repair it, don't try that alone!

If the wall socket is ok, connect the first multiplug alone without any device and check it (Phase-meter or volt meter). Do that with all your multiplugs.

Reinstall everything step by step and check after every cable individually.

The best would be to think about the complete cabling, change to less multiplugs and buy some new ones (not for 2.99 Euro but some with a decent qualtity. Find some where the ground pin can not be bend).

Again: If you have someone who is a learned electrician (gelernter Elektriker), ask him.

Or sent me a mail,

Best wishes and take care

Harald

Harald, thanks for that; my electrical licenses/experience is US-based, with VERY limited Euro stuff - there is nothing like first-hand experience, and I really appreciate your thoughtful and helpful post... Steve