[Elecraft] I need some grounding-strap guidance, if'n you please

Ron D'Eau Claire ron at cobi.biz
Tue Sep 1 16:31:31 EDT 2009


Good story Pete, and a reminder that it doesn't take too many mA of current
to send you flying across the room (or into your grave). Even a bad ground
provides plenty of lethal current at mains voltage.

When I have a shop setup in a basement, garage or anywhere with a floor like
that I make sure the outlets are GFI protected. It's cheap insurance.

Over the past 30 years  we've moved back to the electrical equipment designs
of the 1940's and 50's in which safety is accomplished through insulation
rather than through a grounded enclosure. The fact that few modern tools or
appliances have 3 wire plugs testifies to this approach. Such equipment is
(apparently) very safe. (Safer than many of the old AC/DC radios, etc., of
the 40's and 50's  - especially after us young Hams unknowingly compromised
the insulation by taking a knob off exposing a bare control shaft or leaving
insulators out from under the chassis). 

But the reliance on insulation rather than grounding for safety seems to be
bringing us back many unsafely grounded outlets. It's now very common to
have even brand new construction, signed off by all the appropriate
inspectors, turn up reversed wired outlets and missing grounds. 

Ron AC7AC



-----Original Message-----
> 
>snip<

Many thanks to all! My original question was prompted by an experience
I had as a teenager visiting my uncle in the mid 1960s (oops, the gray
hairs are showing). I was working in his garage, using a metal-housed
electric drill in bare feet on a dry concrete floor. (No cracks about
natural selection at work, please!).

I got a jolt about 2 volts shy of a hairstyle by Boston Edison!
(Although this was in a St. Louis suburb.) So that's what led me to
wonder if an anchor bolt embedded in concrete would constitute a
sufficient ground. It sure seemed to for that drill!

Thanks again for the helpful advice!

With best regards,

Pete




More information about the Elecraft mailing list