[Amel Yacht Owners] electrolysis on jib furling gearbox? [1 Attachment]


Mohammad Shirloo
 

Hello and welcome to the group;
 
Sorry to not address you by your name but I did not see your name in the e-mail.
 
I cannot comment on the source of your particular issue. However if you are connected to shore power in a marina or harbor without a galvanic isolator, you are exposing the boat to a high risk of electrolysis depending on your particular location, wiring and boats surrounding you.
 
I would highly recommend the installation of a galvanic isolator to prevent creating an unintended electrical circuit. Olivier recommended the install on our 54 during the survey. The installation is fairly straight forward and it took us a couple of hours to get done.
 
Respectfully;
Mohammad and Aty
B&B Kokomo
Amel 54 #099


From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Tuesday, January 09, 2018 8:11 PM
To: amelyachtowners@...
Subject: [Amel Yacht Owners] electrolysis on jib furling gearbox? [1 Attachment]

 

Greetings and Happy New Year,

I’m new to the group having purchased “Liebling” SM hull #207 In June 2017.  Now she is “La Querida” berthed in Moss Landing, California.

Over the last several months I noticed something like grease dripping out from the jib furling gearbox and finally dismantled it last weekend.  In general it was in reasonable shape for a 20 year old gearbox.  However the aluminum  disc on the out put shaft showed considerable pitting which I interpret as electrolysis.  On my particular box, the aluminum is in contact with a bronze or brass bushing.  I did some reading on line and was quite alarmed to learn that neighboring boats and poor grounding of the marina shore power apparently can accelerate electrolysis on a well designed and maintained boat such as our Amels.  So two questions:

  1. Has anyone else experienced this electrolysis on the aluminum disc on top of the gearbox?  (or is mine indicative of a bigger problem)
  2. I briefly investigated galvanic isolators as protection for poorly grounded shore power.  Is this worthwhile?

Thanks in advance.

BTW our plans are to cruise to Mexicos west coast after retirement in about 3 years.  Saludos a todas!


Scott SV Tengah
 

Mohammad,

Hope you're doing well and staying healthy. I saw this old post that you had a galvanic isolator installed on your 54? Which one did you use and more importantly, where was it installed? Thanks!

-Scott


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Arno Luijten
 

Hi Scott,

Sorry to barge into your question to Mohammad.
But just as some addition information for you. I have installed a Galvanic Isolator as well last year because of the poor electrical system here in the marina.
I’ve installed a Mastervolt GI7 that is basically a double GI 3.5 in a single enclosure. This is an isolator based on HF-switching technology making it far less heavy then a conventional one. It works well although I do think Mastervolt missed big time on an opportunity to make it much more clever. Actually the device is not made by Mastervolt but by a Dutch OEM that also produces the Mass line of devices sold by Mastervolt.
For one they could have made it fairly easy into a frequency conversion device as well (50<=>60 Hz). Also the regulation of the output voltage is not possible (out voltage is in voltage plus a few %). Finally they also offer a version of the Isolator that can convert 110 to 220 that is not available (?), at least not when I was shopping.
I had some conversation with tech support at the time but their Customer Relation skills are well below par.
So all in all the thing does what it’s supposed to do but Product Management has been sleeping with this thing. For me the main point aside from isolation is the weight as the thing lives in the rear lazarette (see picture). As the 54 is already very much tail-heavy I don’t want to put too much additional weight that I can avoid on the back.


Regards,

Arno Luijten
SV Luna,
A54-121





Scott SV Tengah
 

Arno,

No need to apologize - I am happy to get advice from anyone. I agree that the 54s are far too tail heavy as is.

I am looking at getting a galvanic isolator and it seems the device you installed is an isolation transformer? I know the I.T. is superior but given that I plan to spend relatively short periods in marinas, I thought the slightly inferior but far lighter/cheaper galvanic isolator would be sufficient.

Thoughts?

PS - wow your lazarette looks amazingly clean and dry! I think I need to replace the seal on the lid.

On Sun, Feb 14, 2021 at 2:58 PM Arno Luijten <arno.luijten@...> wrote:
Hi Scott,

Sorry to barge into your question to Mohammad.
But just as some addition information for you. I have installed a Galvanic Isolator as well last year because of the poor electrical system here in the marina.
I’ve installed a Mastervolt GI7 that is basically a double GI 3.5 in a single enclosure. This is an isolator based on HF-switching technology making it far less heavy then a conventional one. It works well although I do think Mastervolt missed big time on an opportunity to make it much more clever. Actually the device is not made by Mastervolt but by a Dutch OEM that also produces the Mass line of devices sold by Mastervolt.
For one they could have made it fairly easy into a frequency conversion device as well (50<=>60 Hz). Also the regulation of the output voltage is not possible (out voltage is in voltage plus a few %). Finally they also offer a version of the Isolator that can convert 110 to 220 that is not available (?), at least not when I was shopping.
I had some conversation with tech support at the time but their Customer Relation skills are well below par.
So all in all the thing does what it’s supposed to do but Product Management has been sleeping with this thing. For me the main point aside from isolation is the weight as the thing lives in the rear lazarette (see picture). As the 54 is already very much tail-heavy I don’t want to put too much additional weight that I can avoid on the back.


Regards,

Arno Luijten
SV Luna,
A54-121





--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Dominique Sery
 

Hello Scott,
I'm in the same situation as you, I rarely go to marinas so I chose to install a Victron galvanic isolator.
It's lighter, smaller, much cheaper and very easy to install.
It works perfectly.
I noticed, in Greece, in some ports a potential difference of 500 mV on the ground between the shore and the boat which seemed enormous to me.
The Victron isolator cuts 600 mVc, which is perfectly in line with my expectations.
My anodes are deteriorating very little since the installation of this insulator 2 years ago.
Sincerely
Dominique
A54#16


Scott SV Tengah
 

Dominique, 

I was looking at that model also. Did you install it in the lazarette in the same place where Arno installed his Mastervolt isolation transformer? 

I was wondering if you could install it in the engine after the lazarette circuit breaker but before it enters the automatic transfer switch (the victron quattro in my case)? It seems far more likely to stay dry in that case. 

If you do as I suggested, it should be isolated from the bonding / ground, no? 

On Sun, Feb 14, 2021, 17:26 Dominique Sery via groups.io <dominiquesery=me.com@groups.io> wrote:
Hello Scott,
I'm in the same situation as you, I rarely go to marinas so I chose to install a Victron galvanic isolator.
It's lighter, smaller, much cheaper and very easy to install.
It works perfectly.
I noticed, in Greece, in some ports a potential difference of 500 mV on the ground between the shore and the boat which seemed enormous to me.
The Victron isolator cuts 600 mVc, which is perfectly in line with my expectations.
My anodes are deteriorating very little since the installation of this insulator 2 years ago.
Sincerely
Dominique
A54#16


--
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com


Dominique Sery
 

Scott,
I made it as simple as possible.
As it has to be installed first after shore power socket and before all devices, circuit-breakers...
I installed the galvanic isolator in the aft trunk, port side, near the dock socket, in a waterproof box on the small shelf.
It is thus installed before the residual current circuit breaker and before the transfer switch. 
Note that the unit is "waterproof" IP 67.
It is simply two diodes mounted in opposite directions embedded in the resin. It is not very sensitive to possible humidity.
Very easy and fast to install, there is only the ground wire to be connected.
Dominique


Arno Luijten
 

Hi Scott,

There are a number of things that can cause galvanic corrosion. Typically a poor grounding system in the marina can be a cause. But there can also be a DC component on the AC power. That is exceptional though.

Amels bonding system is connected to the shore power earth wire via the A/C systems and the watermaker 230V motor so there is that.
There are quite a few marinas that use these steel plates at one more sides of the marina. Quite often these are protected with a galvanic potential to save them from corrosion. This can lead to problems on a boat. I’m not so sure if the threshold voltage of the Victron device will offer enough protection. Also there can be boats next to you with poorly designed shore power systems. Again, I’m not sure if the threshold voltage is sufficient.

So in short, I don’t know if the Victron device will provide enough protection. It may be a good solution for some cases. For sure it is much cheaper and easier to install.
When I read about the device I was not convinced and because of that I did go for the full separation of the shore power. Also because the shore power in this marina is a mess. We are most of the time in this marina as we are residents of St Maarten.
Maybe just for fun I should measure the difference between the shore power earth and the boat’s earth.

To the lazarette: Ours was leaking badly as well, but this was because of the poorly fitted twistlocks as well as worn out O-rings inside the twist locks. Another cause was the pot where the middle stanchion normally resides. Amel made a poor choice here to simply drill a hole and put the pot in with some bolts and caulking. However the core of the deck at that place is balsa. That and the forces exhibited by the stanchion makes that after a while you will get water ingress. In my case the balsa core was rotting in a ring around the hole. So I removed the wet core for the biggest part. Then I left it drying in the hot sun we have here for a few days. Finally I filled the cavity with epoxy and redrilled the bolt holes. Since then the lazarette is dry, even with extensive green water over deck. 

Regards,
Arno
SV Luna,
A54-121


rossirossix4
 

We use the Shoresafe galvanic insulator and it is mounted in the engine room just before the automatic shorepower/generator switch (do not connect after this point because the ground connection of that switch is connected to everything that is 220 and it is not switched.

The Shoresafe product is 1)relatively inexpensive  2)has extra reserve amperage capacity and high quality 3)has an external monitor that indicates both AC and DC leakage and 4)the company will respond quickly and thoroughly to issues or questions.  If you read their material you will see that it is well thought out.  Once we started using the product our zinc usage decline dramatically.

The external monitor can be mounted on the side of the "white 220v box" so you can immediately check for a leak when connecting to shore power (vs having to go into the engine room).

https://www.safeshoremarine.com/products/

Bob,  KAIMI SM429