galvanic isolater

[dreadnought]

hi all, i`m thinking of fitting a galvanic isolater to my shore line connection, i`ve seen one for about £99 can you tell me if its worth the expense do they work, has anyone some experience with them ,many thanks

[Graham.m]

hi all, i`m thinking of fitting a galvanic isolater to my shore line connection, i`ve seen one for about £99 can you tell me if its worth the expense do they work, has anyone some experience with them ,many thanks

 

Yes they work

Is it worth the exspense? Depends to an extent if you spend time moored up in a marine with other boats on shoreline nearby. If you do there is a chance of the hull being eaten away by electrolysis and the costs ot repairing it.

 

Have a look at this might it explain it better http://www.canalboat.co.uk/canal-boats/maintenance/why_do_i_need_a_galvanic_isolator_1_3930242

[b0atman]

there is someone called watts advertises on Canal market place GI's for £50.

[Taslim]

hi all, i`m thinking of fitting a galvanic isolater to my shore line connection, i`ve seen one for about £99 can you tell me if its worth the expense do they work, has anyone some experience with them ,many thanks

Fit one if you are among outher boats and have land line. For about twice that price you could fit an isolation transformer. They are a better option (my opinion) 'cause, baring traumatic breakdown, they last forever.

[nicknorman]

There is quite a variation in quality of GIs, not so much in how well they work normally, but how well they work during and following a major electrical "event". I would check that the GI is compliant with the ABYC standard. Under fault conditions you can have a huge current flowing through the diodes and what you want to avoid is the GI going open circuit. This might not be too apparent but it means that the boat no longer has an earth connection.

 

Best to get a GI with some sort of status monitoring and check the GI with a meter or battery/bulb any time there has been a breaker trip.

[Tony Brooks]

There is quite a variation in quality of GIs, not so much in how well they work normally, but how well they work during and following a major electrical "event". I would check that the GI is compliant with the ABYC standard. Under fault conditions you can have a huge current flowing through the diodes and what you want to avoid is the GI going open circuit. This might not be too apparent but it means that the boat no longer has an earth connection.

 

Best to get a GI with some sort of status monitoring and check the GI with a meter or battery/bulb any time there has been a breaker trip.

 

Amen to that.

 

I would also be worried that a GI might fail short circuit and if it does the earth circuits and RCDs will still work but the hull will have no protection.

[Graham.m]

 

Amen to that.

 

I would also be worried that a GI might fail short circuit and if it does the earth circuits and RCDs will still work but the hull will have no protection.

Buying one that has an indicator of current flows could help. But maybe it is not a bad idea to test it monthly.

Edited December 13, 2015 by Graham.m

[by'eck]

 

Amen to that.

 

I would also be worried that a GI might fail short circuit and if it does the earth circuits and RCDs will still work but the hull will have no protection.

 

Surely better that than have an open circuit failure with the protective earth effectively removed.

 

GI's with short circuit failure by design are now available, Sterling offer the ABYC compliant Pro Save FS. I suspect though that an event that caused up to 5000 amps to flow for a full cycle and so failing the GI, might not go unnoticed but agree with you both that some sort of integrity monitoring would be ideal.

[Keeping Up]

The ones with LED status indicators such as the Safeshore are usually better because the extra diodes, that have to be included to raise the voltage-drop enough to operate the LEDs, give you better protection against the stray earth currents from other boats or onshore equipment. Plus of course you get the instant indication from the monitor, and they do a plug-in version that needs no expertise to fit.

[raymondh]

Fit one if you are among outher boats and have land line. For about twice that price you could fit an isolation transformer. They are a better option (my opinion) 'cause, baring traumatic breakdown, they last forever.

Hi,

Can you please advise details of where I can get an isolation transformer for £200 ish? I have been looking and 3kw ones are around £1000!!!! (Victron) the less expensive all seem to be 3000VA peak 1600VA continuous

I am sure they must be out there but I can't find any

Regards Ray

[nicknorman]

Hi,

Can you please advise details of where I can get an isolation transformer for £200 ish? I have been looking and 3kw ones are around £1000!!!! (Victron) the less expensive all seem to be 3000VA peak 1600VA continuous

I am sure they must be out there but I can't find any

Regards Ray

Have a look for Airlink. By the way, I would get one that can take the full 16A of a standard shore connection, that being about 3600va. The Airlink one seems to be about £400 but you might find it cheaper.

[Graham.m]

 

Surely better that than have an open circuit failure with the protective earth effectively removed.

 

GI's with short circuit failure by design are now available, Sterling offer the ABYC compliant Pro Save FS. I suspect though that an event that caused up to 5000 amps to flow for a full cycle and so failing the GI, might not go unnoticed but agree with you both that some sort of integrity monitoring would be ideal.

 

Any failure is better that open circuit. As you say you lose the protective earth

[GUMPY]

Hi,

Can you please advise details of where I can get an isolation transformer for £200 ish? I have been looking and 3kw ones are around £1000!!!! (Victron) the less expensive all seem to be 3000VA peak 1600VA continuous

I am sure they must be out there but I can't find any

Regards Ray

http://www.airlinktransformers.com/boating_transformers/BT3231/

3.6kva continuous

[Loafer]

Another useful thing to do if you live in a marina, is to dangle another anode over the side, connected by a single conductive wire to part of your hull, maybe one or two along the length of your boat.

 

A friend of mine did this in Falmouth marina, and you could see it visibly bubbling underwater. This is salt water mind, and could be different in fresh water for all I know.

[Graham.m]

Another useful thing to do if you live in a marina, is to dangle another anode over the side, connected by a single conductive wire to part of your hull, maybe one or two along the length of your boat.

 

A friend of mine did this in Falmouth marina, and you could see it visibly bubbling underwater. This is salt water mind, and could be different in fresh water for all I know.

 

Was it a zinc or manganese anode?

[Markinaboat]

A good example here. My 70ft trad is in a compact narrow residential cut with 30 boats in. It came out last week for blacking (overdue) and a hull survey. It had been moored up and permanently connected (as were my neighbours) for more than 4 yrs and the anodes were just 20% worn if that much. The hull thickness was still 10mm bottom and 6 mm sides so no change in over 4 yrs. And on a 24 yr old boat too!

 

Testimony to a galvanic isolator being a no brainer! (Safeshore Marine GI70). Our new (used) boat that we live on has a Mastervolt Isolation Transformer already installed.

Edited December 13, 2015 by Markinaboat

[raymondh]

http://www.airlinktransformers.com/boating_transformers/BT3231/

3.6kva continuous

Many thanks a lot less cash and simple to connect

 

Regards Ray

[Loafer]

 

Was it a zinc or manganese anode?

 

Zinc.

 

Although I don't think I'd ever use a manganese anode. Maybe magnesium at a push, in fresh water only!

[blackrose]

Some sort of isolation is a good idea of you're hooked up to shore power for long periods. Have a look at the Safeshore website for an explanation.

 

http://www.safeshoremarine.com

Edited December 13, 2015 by blackrose

[Graham.m]

 

Zinc.

 

Although I don't think I'd ever use a manganese anode. Maybe magnesium at a push, in fresh water only!

 

I asked because this is an inland water forum and what you described is the sort of reaction a magnesium gives in salt water.

Edited December 14, 2015 by Graham.m

[Loafer]

 

I asked because this is an inland water forum and what you described is the sort of reaction a magnesium gives in salt water.

 

Yes but you asked me if it was a manganese anode, and I've never heard of those. At sea, we always used zinc.

 

[Chewbacka]

 

Yes but you asked me if it was a manganese anode, and I've never heard of those. At sea, we always used zinc.

 

Screen Shot 2015-12-14 at 10.21.42.jpg

Zinc is not very effective in fresh water and so just about all canal boats will use Magnesium. However it is very unwise to use Mg in salty water as it's 'voltage' is too high and they will not last long.

 

If you are interested in anodes and cathodic protection, this is interesting.

http://www.mgduff.co.uk/leisure-craft/cathodic-protection.html

[by'eck]

 

Was it a zinc or manganese anode?

 

Zinc is the preferred sacificial anode for use in salt water and Magnesium (Mg) in fresh water with Aluminium a good half way house if your boat is regularly used in both or brackish water. In fact Magnesium comes at the top of the galvanic table and being least noble proves ideal material for sacrificial anodes on canal boats. Zinc being a little way down but not erroding so quickly in more active salt water.

 

To the best of my knowledge Manganese (Mn) although often confused with Magnesium is a different element and never used as sacificial anode material although it is used in alloys such as manganese bronze for propellors.

[Graham.m]

 

Yes but you asked me if it was a manganese anode, and I've never heard of those. At sea, we always used zinc.

 

Screen Shot 2015-12-14 at 10.21.42.jpg

 

I suspect that Chewbacka has made the point zinc - salt water, Ali - salt or brackish water, Mag - fresh water

 

From what you described earlier I suspect your friend had accidentally bought a Mag anode; because the reaction described is how I would expect a Mag anode to react in high salt water.

[Graham.m]

 

To the best of my knowledge Manganese (Mn) although often confused with Magnesium is a different element and never used as sacificial anode material although it is used in alloys such as manganese bronze for propellors.

 

Thanks, so long since I did my atomic tables, easy to mix the two. Although suspect talking anode people would read correctly.