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On Aug 1, 2014, at 6:21, "Hannu Venermo gcode.fi@gmail.com [electricboats]" <electricboats@yahoogroups.com> wrote:
Not true.
Isolation transformers are supposed to be used on boats - which negates
the matter.
Partly true however -- .. if 2 things go wrong at once, an ungrounded
boat may be a danger.
Every single electrical installation in the world is also dangerous, is
2 things go wrong at once.
This cannot be protected for with grounding.
Water itself is not particularly dangerous .. nor is 120VAC, nor 240 V ac.
A live 240 line is not actually physically dangerous to people, in general.
GFIs, required everywhere, will safely trip before harm can come to
people (30 ms is typical).
I have had 240 VAC shocks many times (maybe 7), one of which was my own
fault.
None was more than unpleasant.
You mentioned "great risk" with 120VAC. This implies imminent, common,
deadly harm, and I dont think so, not with 120VAC.
Medium power, ie 480V 3-phase and substation transfer lines at 20.000 V
and up, are a totally different manner.
None are commonly installed near boats.
Hollywood and media portraials of electricity simply dont work that way
with common, low power, 240V.
Note we are referring to *accepted and legal practices* according to
ABYC and worldwide installation codes.
On 01/08/2014 16:04, Chris Hudson clh5_98@yahoo.com [electricboats] wrote:
> Considering you are in fresh water you are putting people at great
> risk with your 120VAC ground left floating at the dock. If for some
> reason you lose your ground connection to the dock, any person could
> become that connection in the event of a fault.
>
> Chris
>
> Sent from myPhone
--
-hanermo (cnc designs)
Posted by: Chris Hudson <clh5_98@yahoo.com>
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