My work bench is live!

Miscellaneous
1

Hi folks,

I don’t know whether it’s the right expression, but my work bench is live (ger.: steht unter Strom).

It was a normal friday afternoon when I wanted to complete my MBox. I touched a metal plate of my workbench and suddenly… bzzzz :o!

Fortunately I managed to get myself off the plate so I touched it just ca. 2 sec.

I survived.

I took a voltmeter and measured about [glow=red,2,300]225V[/glow] AC (Germany) between GND and the work bench.

And I still don’t know where the 230V come from…

I just wanted to warn you. Always check the voltage between you and your work bench  ;D

p.s.: could this be the reason for jittering AINs?

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:o

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could this be the reason for jittering AINs?

yes, of course! The metal plate is like a huge 50 Hz sender - take care!

In general I would never tinker with electronical gear on a metal workbench, you should put an additional wooden board at the top

Best Regards, Thorsten.

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In general I would never tinker with electronical gear on a metal workbench, you should put an additional wooden board at the top

Best Regards, Thorsten.

It actually has got a kind of wooden board at the top, but the plate doesn’t cover the whole surface. There’s still a ca. 8cm rim. And I touched it.

5

:o Damn that is scary!

I’m just gonna quote myself on the wiki:

Be safe. Don’t F*&% around with safety, tools, your workspace, etc

You were lucky this time… Please be careful!

Be it something trivial, like no taking time to back up files and losing them, or not putting on a grounding strap and frying your motherboard, or something serious, like not taking time to put the tools away and shorting an extremely large capacitor with a metal screwdriver held in your hand while you’re taking a break (that was me), I think many of us will have fallen victim to our impatience, at some time or other in our electronics experience.

I mean… when we ask ourselves “Do I really need to spend $500 on a bench when I’ve got this one here?”, we are so busy thinking “ooh I can’t wait to have my midibox!”, that we rarely also consider, “Well gee, this desk could actually be really dangerous, imagine how sad my Wife would feel if I were dead?”  :'(

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…plus, you’d never get to play with your MIDIBox if you fried yourself  ;D

(Just couldn’t be so serious any longer!)

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I was wondering myself about the bench, because my grand-grandfather has already used it.

I’ve measured the Voltage btw. the gnd-contact in the socket at the wall and the bench. I think my shoes isolated a bit.

I’ve already a theory where the voltage could come from.

There is a kind of a fountain in my garden. The power for it comes from a socket near my bench. But the cable from the pump was too short so I had to use an extension cord. The two cables are connected in the underground. I’ve bought a special box for  this connection, but it seems not to be watertight anymore…

I’ve pulled the plug for the pump out of the socket and It’s safe now.