which galvanic Isolator advice

[jon and michie]

Hi - I am about to take ownership of a sea ray 315 which would appear to have never had a galvanic isolator fitted - As this is my first boat how do I determine which one is suitable for my boat.

All opinions/recommendations are welcomed

Jon

 

[VicS]

Hi - I am about to take ownership of a sea ray 315 which would appear to have never had a galvanic isolator fitted - As this is my first boat how do I determine which one is suitable for my boat.

All opinions/recommendations are welcomed

Jon

I take it you want to fit one because you will be plugged into a shorepower supply for prolonged periods and that the shorepower earth is bonded to the DC system negative and/or the anodes.

Take your pick of what is available I think........ be sure to buy one with an adequate current rating to cover the max fault current it may have to withstand before the circuit trips. They come in various sizes from 16amps upwards.


There is a lot of useful info on the Safeshore website http://www.safeshoremarine.com/ but its not the most coherent of websites IMO.

You might be interested in Safeshore's quick fitting idea although wiring in a GI permanently is no great deal.

 

[Anthony]

Hi - I am about to take ownership of a sea ray 315 which would appear to have never had a galvanic isolator fitted
Jon

Are you sure, Sea Ray generally fitted them as standard, how old is the boat? If you have the manual (or get it from their website), they have a wiring diagram in that will show if one is connected, they are sometimes fitted in hard to find places, on the 315 it is normally behind the panel the shore power plugs into in the aft locker.

Ants

 

[jon and michie]

Thank you for the replies so far

VicS - it will be in the shore power for prolonged periods roughly 3 weeks while I am away - so basically looking at one what is adequate as a newbie to owning a boat if there is any recommendations - I am pretty good with my hands but at the same time a plug and play would be an advantage.

Anthony - I will check this out if there is one fitted - however after my recent trip to the boat after a survey the leg casing had quite severe corrosion and the anodes where doing their job as they are about 50% used.

thanks again
Jon

 

[Tranona]

16A will be fine. Available from a variety of sources, but probably easiest from Fore 4. Cost £70 and easy to install. However, agree with Anthony, probably already fitted.

 

[Scubadoo]

I have just fitted one myself and I can recommend Sterling Power from MDS: http://www.mdsbattery.co.uk/shop/productprofile.asp?ProductGroupID=8924

If the boat is out of the water you can check with a meter if the marina has a slight "leak" on their earth. From memory, with the shorepower connected, set the meter to mv and put one probe on the anode and the other to the ground (wet the ground with some water), if you get no reading you will probably find the GI is doing it's job, if you get something like 20mv (which was in my case) then I would say you don't have a GI.

 

[steve930]

It should already have one fitted Jon. My last boat ( 1990 220da sundancer ) had one fitted from the factory & worked on a friends 240da sundancer which also had one.

Obviously double check yourself though. The Americans are pretty advanced when it comes to boat electrics

 

[michael fesler]

I am also looking for some advice. Seems there are two types of product, (i) fail safe - 200 quid and (ii) non fail safe about 100 quid. My research indicated that whilst non fail safe probably "never go wrong" if they did they may expose boat users to electrocution because the earth link is broken. My heart says go for the cheaper version and check them every six months or so for function, my head says, why take the chance, pay the extra 100 quid and get the fail safe version [ if this malfunctions it maintains the earth link]. Any advice from those more experienced than I.

 

[kashurst]

As long as you have an RCD (residual current detector) in the mains switch panel you are very unlikely to have a problem in the unlikely event the galvanic isolator failed.

 

[michael fesler]

As long as you have an RCD (residual current detector) in the mains switch panel you are very unlikely to have a problem in the unlikely event the galvanic isolator failed.

how about the observation that over reliance on a marina's ability and desire to regularly check its RCB's adds further substance to the having a fail safe GI

 

[kashurst]

sorry should have explained more carefully - make sure you have an RCD on your BOAT control/switch panel - don't rely on the marina stuff.

 

[jon and michie]

Right as I am now in ownership of the boat I have had a good look and I have found the galvanic isolator however one of the earth wires was a tad loose which I tightened up. I also found that 2 of the adapter pugs (euro to English) which the previous owner left has corrosion on the pins ( may have something to do with the electrics )
What I have found on the main switch panel is when the shore power is connected there are 2 lights 1 green and 1 red - the red light is for reversed polarity which isn't lit fortunately and the green light to say the electricity is on and ok - this doesn't light could my galvanic isolator be faulty ??
I am thinking of buying a new isolator with led warning lights on more as a peace of mind than anything.

I have also found that 1 of the previous owners seemed to like the art of butchery when it came to electrics as the stereo power wires have been cut and badly connected with the odd live wire exposed behind the main switch panel same with the t.v and dvd player.

going back to the boat this Friday armed with tools etc

Jon

 

[kashurst]

Unlikely to be a damaged galvanic isolator, you can test it with a multimeter that has a diode test. Put the probes either side of the terminals an you should see approx 1.5v ish. Swap probes over and measure again should give a similar reading. Your neon light indicators will not becbothered by the presence of a GI. But they may well not becworking if a few years old. If not sure get a sparky to have a look. Wiring butchery is a common ailment, lots of muppets out there. Good luck with new boat

 

[GSL]

I have a Sea Ray 460 that was a European spec (220 volt) boat from new. The red and green reverse polarity lights on the distribution board do not seem very reliable to me.

My previous Sea Ray 400DA (US Spec 100 volts) also had slightly intermittent reverse polarity lights.

Graham