I do not believe there is any Marine situation where the "White, Neutral, Grounded" wire should be connected to the 12V negative. Not sure even about the "Green, safety, GroundING" wire. Checking Norm's comment below, I would note that when on dock power, the dock neutral is grounded at the meter. You will still get electrocuted, if you complete the circuit from hot to a steel boat or to water. The PI circuit isolator is the safe way to go. Lee Haefele ----- Original Message ----- From: <[email protected]> To: <[email protected]> Sent: Wednesday, December 09, 2009 1:44 PM Subject: Re: [Liveaboard] Ground Loop
> > Philip, > > It depends. > > Grounding the neutral side of the ac system will let you get electrocuted > if your body is grounded and you touch a hot ac wire. > > There is a system, used on the ships I sailed on, sometimes know as the > "bath tub" system (I don't know why). All of the ac is above ground. The > neutral line is not grounded. There is no wire connecting the neutral > (whites) terminal strip to the grounding (greens or bares) terminal strip. > Only the equipment housings (the green or bare wire in shoreside systems) > are grounded. > > This way if you are standing on wet, salty, decks and touch an hot ac > conductor you will not have any current flow through you. The ships often > used 440 vac for their heavy duty equipment so this was a big deal. 440 > is > much more deadly than 120. > > The downside is that this system depends on having flawless insulation. > There were indicators (light bulbs from each phase to ground, and/or > meters, for example) to show leakage and an electrician who works > constantly to clear these "ground faults". > > I fixed the hum in my stereo by installing a DC pi style (two capacitors > and one inductor) filter in the DC line. I originally bought the filter > from Radio Shack but they don't carry them any more. Recently I bought > some after a short search on line. > > > Norm > S/V Bandersnatch > Lying Julington Creek FL > > >> [Original Message] >> From: Philip <[email protected]> >> To: <[email protected]> >> Date: 12/9/2009 10:12:12 AM >> Subject: [Liveaboard] Ground Loop >> >> I have discovered the cause of the 60 cycle humm in my DC powered sound >> system when connected to my AC powered computer. Seems like I have a >> ground loop. I corrected the situation by running a ground wire from my >> AC ground to my Battery negative. Am I going to create any problems by >> doing this? >> >> Thanks for the help. >> >> -- >> Philip Lange AE4OV > > > _______________________________________________ > Liveaboard mailing list > [email protected] > To adjust your membership settings over the web > http://www.liveaboardnow.org/mailman/listinfo/liveaboard > To subscribe send an email to [email protected] > > To unsubscribe send an email to [email protected] > The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ > > To search the archives > http://www.mail-archive.com/[email protected] > > The Mailman Users Guide can be found here > http://www.gnu.org/software/mailman/mailman-member/index.html -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.426 / Virus Database: 270.14.100/2554 - Release Date: 12/09/09 07:32:00 _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
