[sdiy] ESD grounding in USA

[Seb Francis]

  On 18/10/2010 14:48, Tom Corbitt wrote:
> An important note. The wire doesn't connect directly to the wall earth
> connection, it passed through a large ohm resistor (most of the ones
> I've seen are 10 Meg) Connecting a wire straight from your wrist to
> earth is a BAD thing.

Yes, absolutely!

The coiled wristband cords all seem to have at least 1Meg built in, and the UK and Euro plug adapters have an additional 1Meg between the earth pin and each banana socket.

> There are a lot of companies that make a plug with the resistor that
> connects to your standard banana jack. I also have seen a disposable
> strap system packaged in some computer equipment before; they were
> cloth and intended to be connected to the metal chassis of the server
> while you installed the upgrade you had just purchased. Packaged a lot
> like a band-aid. I remember they had 3M all over them.
>
> Here's a pic of one of the plugs, you can probably find a cheap
> version with some searching.
> http://www.grainger.com/Grainger/IDEAL-Replacement-Grounding-Plug-3T891?BaseItem=3T890

Ah ok, just found a similar looking device on evil-bay for $2.98 each ( http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&Item=180547018176 ).  Not sure if I can squeeze a banana socket (&1Meg resistor) into one of these - I guess I will order one and find out.  Alternatively, mounting a 10mm or 4mm snap stud might be a solution.

I'm really surprised no-one makes an off the shelf Earth Grounding Plug for US type outlet.  Perhaps historically mains grounding has been less reliable in US?

Thanks,
Seb