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Brent,
I have a question about the information you
provided.
Was the tank isolated from ground? Meaning....was
there a path for power to reach earth? If there wasn't....the fish would never
get shocked. Electrical potential isn't what kills you....its the movement of
current that causes harm.
You said you got shocked....meaning
you were the path to ground (earth).......hence why
you got shocked.
So.......just because the water ( in the tank) had
potential.....isn't the same in the ocean. The ocean isn't isolated from
earth....it set's right on it.
James Long
Owner/Designer
Lil Brother LLC (Instrument Division)
----- Original Message -----
Sent: Monday, August 06, 2007 11:27
PM
Subject: RE: [PSUBS-MAILIST] Battery
Safety Issues
James,
Fish and
A/C electricity. Now this I have some personal experience, not professional
experience mind you, but experience none the less. I grow up with tons of
aquariums, did I say tons, I meant tons and tons, both fresh and
saltwater. I could of filled a large pet store with fish, and I did once. Any
who not all electrical aquarium accessories were built well, for being used on
aquariums, in the 70's and 80's. Needless to say I got shocked and felt
tingles many times while working on the tanks. From what I could tell the fish
never died from it. Not to say that it wasn't bad for them, or that if the
load was higher it would. I read a few articles in fish magazines about it as
well, and they said it wasn't good for the fish. I got juiced pretty good more
then once and the fish just looked entertained, not dead. ;
)'
Thanks for
the data James.
Regards,
Brent
Hartwig
From: lil_brother_llc@bellsouth.net
To:
personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Battery
Safety Issues
Date: Mon, 6 Aug 2007 22:31:09 -0500
Brent,
The problem with an A/C system in a sub is actually
two fold. Let me explain:
A/C is used for electrical lines because of the use of
ground (earth). Most A/C components have an external grounding point incase
something goes wrong inside and causes the whole component to become "live".
With a system in a submersible.....you would not only have to provide the
two wires to run the equipment, you would also have to provide the extra
ground fault system to ensure no power is being leaked into the water or the
hull. The electrical design could get pretty complex.
This is not the same as driving a three phased
brushless DC motor....this is much more complex.
Also you have to consider the ramifications to the
marine life if something does go wrong.....you could kill quite a few
fish/animals if your power were to get into the water.
I don't think you could ever totally isolate the
interior (from electrical inclusion from flooding) to prevent power
absorption, it would be nearly impossible. It would be much easier to place
a ground fault system in place to kill the power if it detected the
situation.
The problem with A/C....you don't know which way the
current will go. It will take the path of least resistance.....which may not
be the direction you plan for it to go. An A/C power system requires very
careful planning......if you want to use it in a psub.
Also.....as in a previous message....you do not want
your hull to have any electrical potential for it
causes electrolytic problems.
James Long
Owner/Designer
Lil Brother LLC (Instrument
Division)
----- Original Message -----
Sent: Monday, August 06, 2007 8:02
PM
Subject: RE: [PSUBS-MAILIST] Battery
Safety Issues
James,
You
bring up a point I was thinking about with regards to grounding
the batteries to the sub. Most paints don't have much if any
electrical insulating properties, so the electrical charge, if it's AC
power, would just migrate through the hull and then out to the
surrounding water, and then into the ground, right? If it's DC power then
it's just going to keep mostly to it's self between the negative and
positive points or leads? So what I'm getting at is that if a
sub is built with syntactic foam and/or a heavy coating of Rhino liner
type coating, (of which one or both are likely to be
good electrical insulators) on the interior of the sub,
wouldn't the AC power then have a harder time getting out of the sub,
unless the power systems were grounded to the sub, so the power can get
out easier? I was just thinking that if the power has to leave
through the area where the leak is, and/or through the open hatch, or
which your trying to leave through, you would get a real nasty or deadly
shock. Especially since allot of leaks are jumped on by the operator(s) of
the sub, to fix them.
Regards,
Brent
Hartwig
> From:
lil_brother_llc@bellsouth.net
> To:
personal_submersibles@psubs.org
> Subject: Re: [PSUBS-MAILIST]
Battery Safety Issues
> Date: Mon, 6 Aug 2007 14:07:56 -0500
>
> Joe,
>
> I think that is a somewhat different type
of issue. Remember that AC doesn't
> require much to shock you.
Just providing a path to ground (earth) will get
> you shocked. On
the other hand DC will only shock you when you provide a
> path to
it's opposing pole.
>
> I can see why you wouldn't want your
shore power energized when cleaning the
> bottom on your boat. A/C
is sometimes "leaky"(motor cases, pump cases, etc.)
> and the leak
would be finding it's shortest path to ground(earth). If you
> got
it that path.......it would be a bad thing(depending on the current
> present). I refrain from working with A/C as much as
possible.....but there
> are cases A/C is the best method.
>
> Being in a psub filled with water (with submerged batteries)
wouldn't be a
> joy ride, but I don't think it would be much more
than a tingling sensation.
> I don't think you would be worried
much about the tingling sensation anyway..
> You would have more
important things on your mind. But I also would try to
> have my
power leads pretty close to each other.....not separated on each
>
side of the hull. But the design requirements for most electrical systems
> will have the lead close anyway.......wouldn't be much use if
they were not
> connected to the same system. Also...I wouldn't
connect my hull to the
> negative side (as most craft are...like
cars).......could present a problem.
>
>
> James
Long
> Owner/Designer
> Lil Brother LLC (Instrument
Division)
> ----- Original Message -----
> From: "Joseph
Perkel" <joeperkel@hotmail.com>
> To:
<personal_submersibles@psubs.org>
> Sent: Monday, August 06,
2007 1:36 PM
> Subject: Re: [PSUBS-MAILIST] Battery Safety
Issues
>
>
>
> James,
>
> Thank
you for the info. I remember reading an article once with respect to
a
> "zone" while cleaning your boat bottom dockside. I cannot
remember the
> details, or why it was an issue, something regarding
stray shore power
> currents.
>
> In any case, I will
look over the electrical details from a safety
> perspective in
great detail.
>
> Joe
>
> >From: "Lil Brother
LLC" <lil_brother_llc@bellsouth.net>
> >Reply-To:
personal_submersibles@psubs.org
> >To:
<personal_submersibles@psubs.org>
> >Subject: Re:
[PSUBS-MAILIST] Battery Safety Issues
> >Date: Mon, 6 Aug 2007
12:27:37 -0500
> >
> >Joe/Brent,
> >
>
>Yes...you will get some shocking effect, but it will not be severe.
The
> >kill
> >zone with the battery submerged (or
breaker box) will be in-between the
> >positive and negative
poles of the battery/connection.
> >
> >Remember there
are underwater welders that deal with this all the time. It
> >is
an uncomfortable thing to do....but is not life threatening, until
you
> >enter the kill zone.
> >
> >James
Long
> >Owner/Designer
> >Lil Brother LLC (Instrument
Division)
> >----- Original Message -----
> >From:
"Joseph Perkel" <joeperkel@hotmail.com>
> >To:
<personal_submersibles@psubs.org>
> >Sent: Monday, August
06, 2007 7:03 AM
> >Subject: RE: [PSUBS-MAILIST] Battery Safety
Issues
> >
> >
> >Brent,
> >
>
>This is one of those issues in the "back of my mind" as well. I
figured to
> >delve in further at the proper time but, perhaps
someone can elaborate.
> >
> >Joe
> >
>
>
> > >From: Brent Hartwig
<brenthartwig@hotmail.com>
> > >Reply-To:
personal_submersibles@psubs.org
> > >To: PSUBSorg
<personal_submersibles@psubs.org>
> > >Subject:
[PSUBS-MAILIST] Battery Safety Issues
> > >Date: Sun, 5 Aug
2007 21:22:09 -0700
> > >
> > >
> >
>
> > >If you have one or more batteries in the pressure
hull with you, and not
> >in
> > >a sealed off area,
how do you keep from being electrocuted, if the inner
> >
>hull floods? Will not the batteries short out in fresh water, and
even
> >more
> > >so in saltwater? I would love to be
enlightened. ; )' Perhaps someone
> > >else wants and/or needs
to know as well.
> > >
> > >Even if the batteries
are in pods, or another hull section, will not the
> >
>breaker box cause and other wire cause your trouble?
> >
>
> > >
> > >Regards,
> > >Brent
Hartwig
> > >
> > > " I kind of like doing the
impossible. "
> > >
> > > ~ Walt Disney
>
>
> >
> >
> >
> >
>
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