Carianne
Active Member
We have our boat moored on the River Hamble... I have been doing a lot or reading about Galvanic Isolators, is it worth having one fitted? Would be grateful for any thoughts,,,,
Galvanic Isolator......thoughts?
- Thread starter Carianne
- Start date
Alpha22
Well-Known Member
If you spend anytime hooked up to shore power it is a good idea to have one. If you never use shore power then you don't need one.
If the question is......."I think I should get one, but things are OK at the moment, could that change and disolve my props?" Then you need one......
The problem is of course, it may never do anything..... the danger is, if you ever need one, you wont find out until it's way too late..... and expensive.
Weigh the costs up..... new props/legs v's a little box and half an hour to fit it.
If the question is......."I think I should get one, but things are OK at the moment, could that change and disolve my props?" Then you need one......
The problem is of course, it may never do anything..... the danger is, if you ever need one, you wont find out until it's way too late..... and expensive.
Weigh the costs up..... new props/legs v's a little box and half an hour to fit it.
Tranona
Well-Known Member
Does not need much thought. If you regularly hook up to shorepower - irrespective of location it is wise to fit one.
paul salliss
Well-Known Member
Am moored in the same area as you, just had one fitted and pleased I did, feel free to PM me any time,
BruceK
Well-Known Member
If I may expand on this thread. I do not use shore power but on rare occasion use a genny that I sit on the pontoon and use the shore power lead. I replaced all anodes in August. In January when I was against the drying wall the annodes were completely shot. And I mean all but gone. Total genny use during that time was about 5 hours, hooked up to shorepower in a visiting port for 12 hours. Annodes correct for salt water. Yachties nearby say their annodes good for a couple of years. So what is my likely issue?
edit
The most annode wear was on the lower leg just forward of the props and the annodes in the prop hubs. Wear lessens towards transom. Props are stainless steel if that makes much difference here.
edit
The most annode wear was on the lower leg just forward of the props and the annodes in the prop hubs. Wear lessens towards transom. Props are stainless steel if that makes much difference here.
Last edited:
Sandyman
Well-Known Member
This might be of interest................http://www.yachting-life.net/new index/frames3/electrol_frame.htm
Tranona
Well-Known Member
Using the generator is not the same as using shorepower. The purpose of the galvanic isolator is to isolate from the marina electric system, so if you are not plugging in then the galvanic isolator will not reduce your anode erosion.
paul salliss
Well-Known Member
PM just sent. Taranona is not wrong in his post, it only ap
Lies if you use a fair bit of shore power, if you do get one fitted
Lon nan Gruagach
Well-Known Member
To add to Alpha22's list:
If you have a metal hull and onboard genny or inverter, you need one.
Also, a genny on the pontoon really ought to have an earth stake, in which case, you need a GI
If you have a metal hull and onboard genny or inverter, you need one.
Also, a genny on the pontoon really ought to have an earth stake, in which case, you need a GI
Spi D
...
I got one (Sterling) for peace of mind and noticed that anodes doesn't need annual replacement anymore
Sterling has a pretty good explanation on the site (below product image)
http://sterling-power.com/collections/zinc-savers/products/zinc-savers-galvanic-isolators
Sterling has a pretty good explanation on the site (below product image)
http://sterling-power.com/collections/zinc-savers/products/zinc-savers-galvanic-isolators
Steruth1
Well-Known Member
I also have just had my boat fitted with these, not cheap but better than your props being eaten ?
Blue Sunray
Well-Known Member
I have a suspicion that the previous owner fitted one to my boat, but where would I look to find it/check?
rafiki_
Well-Known Member
If you have one, it should be as near to the shorepower socket a sensible. So try and follow the cable from the socket.
Lon nan Gruagach
Well-Known Member
Follow the incoming shore power earth. My first guess would be between the panel mount plug where the shore cable connects and the 240V distribution panel.
You can test to check operation and presence:
Turn off any generator or inverter.
Plug shore power cable into boat but not shore.
Plug in a piece of domestic equipment with metal case to 240V socket.
With multi-meter set to diode test connect probes to shore power earth pin and equipment case. Swap probes around.
Results:
No reading: bad earth or equipments case is not earthed.
0V both readings: no GI
0.7V(700) or 1.4V(1400) both ways: functioning GI.
mixture of above: malfunctioning GI
Blue Sunray
Well-Known Member
Thank you I'll have a dig around,
superheat6k
Well-Known Member
Five hours on shorepower is not going to eat your anodes. So something else at play here, and either you are sitting in a stray current path that is routing through your bonding circuit, in which case a GI will have no affect whatsoever, or you have a leakage from your 12v DC.
Most likely culprit is bilge pump flappy switches.
Simple check - with all normal services off (I assume you do turn the batteries off when moored), disconnect the +VE from the battery driving the bilge pumps or any other 'Maintained' (on all the time) services.
Then set your VM to DC volts and measure the voltage between the +VE connection and the +VE battery connection. This should be 0 volts. Any voltage mean something is trying to draw battery current, and even a small voltage will easily dissolve zincs over a season. Mine was my flappy bilge pump switch, but could also be any wire at +VE running through bilge water with a dodgy insulation.
Nigel Calder is your friend when it comes to Galvanic and Electrolytic corrosion, and these two are not quite the same thing.
Baseplate
Active Member
............or something simple such as being tied up near a steel-hulled boat.
NoviceRod
Well-Known Member
My first boat did not have a GI, and the anodes were gone after 12 months.
The current boat has a GI, and the anodes are about 50% worn after 12 months.
I hook up to shore power for the winter to run heaters/dehumidifier, but generally do not hook up in summer.
The current boat has a GI, and the anodes are about 50% worn after 12 months.
I hook up to shore power for the winter to run heaters/dehumidifier, but generally do not hook up in summer.
BruceK
Well-Known Member
Thank you for the detailed response Superheat6k :encouragement: I will look into that and see what readings I get. I think you may well have hit the nail on the head there. There is one loom that runs under the engines on the bilge floor and invariably lies in the last 1/2 inch of water the pump doest pick up. I'm guessing that is where I will find the culprit. ta 
Carianne
Active Member
Thanks all for your input, it seems silly not to fit one , that will be next on the list...... After working water..... Not a great start to being a boat owner:-(
