I did qualify the statement indicating it should be properly sized. A single 60 amp isolator is cheaper than two 30 amp ones.
Although pricey the 'fail safe' style of isolator do not require remote monitors. I suppose if you didn't care about regulations or certification you might choose to install one without fail safe and without the monitor; or go down the DIY route. Ed On Oct 28, 2015 12:25 PM, "S Thomas via CnC-List" <cnc-list@cnc-list.com> wrote: > Ed, > What you say is true from the perspective of having effective > galvanic isolation, but there are a couple of design issues that come to > mind. In order for galvanic isolation to work, all wiring grounds to the > boat must be interrupted by a galvanic isolator. This means that if there > are two shore power receptacles then both of them would have to have their > wiring grounds taken to the isolator and then out again to the distribution > panel(s). From an engineering perspective, a wiring ground only needs to > have enough capacity to reliably trip a circuit breaker without catching on > fire, but most electrical codes require that they have the same capacity as > the main conductors. In other words, if you care about regulations and some > people on this list have indicated that they do, then the galvanic isolator > would most likely have to have at least the current capacity of the sum of > both shore power receptacles. > According to the instructions that came with a galvanic isolator that > a friend of mine bought last year, a galvanic isolator requires an > (optional and at an additional cost for that particular product) indicator > light to be ABYC compliant. I was shocked at the price tag on the > commercial units. The prices are grossly out of line with what they > actually contain. > If you don't care about the light and just want something that works, > then a big enough bridge rectifier, 30 amps for example, with the DC > terminals connected together will work fine and cost a lot less than > something that says "marine" on it. The voltage rating of the rectifier > does not matter, just the current rating. It will provide about 1.2 volts > of isolation from the mains ground. > > Steve Thomas > Port Stanley, ON > > ----- Original Message ----- > > *From:* ed vanderkruk via CnC-List <cnc-list@cnc-list.com> > *To:* cnc-list@cnc-list.com > *Cc:* ed vanderkruk <primeinter...@gmail.com> > *Sent:* Wednesday, October 28, 2015 11:28 > *Subject:* Re: Stus-List Galvanic isolator - Good idea? > > Although there are other practical reasons to have two devices I don't > think the power source of the receptacles applies. Even if the two power > circuits have a selector switch the ground / earth conductor in not > switched and almost certainly common across both on the boat. Thus your > boat bridges the ground circuit of the two incoming power receptacles but > they would likely share a common ground at or near the dock in any case. As > the isolator is in-line of the grounding conductor one properly sized > device could, where installation is practical, handle both power > receptacles. > > Ed > On Oct 27, 2015 9:31 PM, "Dennis C. via CnC-List" <cnc-list@cnc-list.com> > wrote: > >> Joel, >> >> I have the Newmar GI-30 on Touche'. >> >> I recently installed two GI-30's on an IP35 with separate 30 amp shore >> power inlets. Did some research on combining the two shore power circuits >> on one isolator and, in the end, decided it best the isolate each. Part of >> the logic is you have no gaurantee that two 30 amp receptacles at a marina >> will be wired from the same source. >> >> Dennis C. >> On Oct 27, 2015 12:47 PM, "Joel Aronson via CnC-List" < >> cnc-list@cnc-list.com> wrote: >> >>> And I have 2 30 amp circuits (although I only use one) and the cheap one >>> can handle both. >>> >>> I don't mind the neighbors eating my zinc, it is the Max-Prop that is >>> off the menu! >>> >>> Joel >>> >>> On Tue, Oct 27, 2015 at 1:39 PM, Della Barba, Joe via CnC-List < >>> cnc-list@cnc-list.com> wrote: >>> >>>> My Quicksilver and this one ( >>>> http://www.defender.com/product.jsp?path=-1|328|2290032&id=1118395) >>>> have the ABYC required failsafe capacitors. The cheap one does not appear >>>> to meet this standard. >>>> >>>> Joe >>>> >>>> Coquina >>>> >>>> >>>> >>>> *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of *ed >>>> vanderkruk via CnC-List >>>> *Sent:* Tuesday, October 27, 2015 1:20 PM >>>> *To:* cnc-list@cnc-list.com >>>> *Cc:* ed vanderkruk >>>> *Subject:* Re: Stus-List Galvanic isolator - Good idea? >>>> >>>> >>>> >>>> I put one in when I refurbished my A/C electrical side. >>>> >>>> It isolates you from your neighbors which might slow down the zinc >>>> consumption ... unless of course it is issues on your own boat causing you >>>> problems. >>>> >>>> Many surveyors would recommend one if you are in a marina with shore >>>> power. >>>> >>>> The particular one you have listed doesn't seem to be a 'fail safe' >>>> model as the others in the same catalog category. Which is why they mention >>>> a remote monitor being required. >>>> >>>> Ed >>>> >>>> On Oct 27, 2015 12:48 PM, "Joel Aronson via CnC-List" < >>>> cnc-list@cnc-list.com> wrote: >>>> >>>> Does anyone use one of these: >>>> >>>> >>>> >>>> http://www.defender.com/product3.jsp?path=-1|328|2290032&id=605562 >>>> >>>> >>>> >>>> Does it slow/stop electrolysis? Most of the boats on my dock are >>>> plugged in, and I go through a zinc or two a year. >>>> >>>> >>>> >>>> Will an isolater do anything besides lighten my wallet? >>>> >>>> >>>> >>>> -- >>>> >>>> Joel >>>> 301 541 8551 >>>> >>>> >>>> _______________________________________________ >>>> >>>> Email address: >>>> CnC-List@cnc-list.com >>>> To change your list preferences, including unsubscribing -- go to the >>>> bottom of page at: >>>> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >>>> >>>> >>>> _______________________________________________ >>>> >>>> Email address: >>>> CnC-List@cnc-list.com >>>> To change your list preferences, including unsubscribing -- go to the >>>> bottom of page at: >>>> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >>>> >>>> >>>> >>> >>> >>> -- >>> Joel >>> 301 541 8551 <301%20541%208551> >>> >>> _______________________________________________ >>> >>> Email address: >>> CnC-List@cnc-list.com >>> To change your list preferences, including unsubscribing -- go to the >>> bottom of page at: >>> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >>> >>> >>> >> _______________________________________________ >> >> Email address: >> CnC-List@cnc-list.com >> To change your list preferences, including unsubscribing -- go to the >> bottom of page at: >> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >> >> >> ------------------------------ > > _______________________________________________ > > Email address: > CnC-List@cnc-list.com > To change your list preferences, including unsubscribing -- go to the > bottom of page at: > http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com > > > _______________________________________________ > > Email address: > CnC-List@cnc-list.com > To change your list preferences, including unsubscribing -- go to the > bottom of page at: > http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com > > >
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