>If you cross-connect your ham & AC power grounds, any such fault currents
will flow in your ground system too, for better or worse.
AFAIK, every piece of ham gear that uses a three prong AC cord has the
safety (green) wire securely attached to the chassis. If you attach a
ground strip from the chassis to the ham system ground, does this meet your
definition of "cross connect"?
Keith NM5G
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Martin AA6E
Sent: Friday, February 25, 2005 3:11 PM
To: keith@dutson.net; towertalk@contesting.com
Subject: Re: [TowerTalk] Ground system design, RF vs AC
Keith,
I believe "fault" is the general electrical term for power going where it
shouldn't. That's why we have protective system grounds in AC systems. If
there is a short circuit in an appliance connecting the hot side to the
chassis, a fault current flows in the ground lead and the user is protected.
A GFCI detects even tiny fault currents and shuts off the circuit asap.
(It detects a difference between hot & neutral current, as you
suggest.) That's a good thing, but old-fashioned fault protection involves
blowing the upstream fuse or breaker with an overload current.
That's one reason why your branch circuit wiring has to be matched to your
breaker - to be sure it will trip quickly if there is a short.
If you cross-connect your ham & AC power grounds, any such fault currents
will flow in your ground system too, for better or worse.
-Martin (who is not an electrician)
--- Keith Dutson <kjdutson@earthlink.net> wrote:
> You wrote:
> >The problem with connecting the AC green wire to the radio room
> ground and
> then connecting my bulkhead "SPG" to a new ground rod or even a
> perimeter ground connection is that my radio installation becomes part
> of the AC protective ground system for the house. That is, any house
> fault or other current will partly be routed through my radio ground
> system. Is that what we want?
>
> When you say "house fault" I assume you are referencing a ground
>fault circuit interrupter (GFCI) system. Such a system interacts with
>the white neutral ground, not the green safety ground. So the answer
>is yes, we do want the safety ground connected.
>...
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Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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