Re: [Amel Yacht Owners] Isolated grounding question - solar installation

hanspeter baettig

The solar panels of your previous boat from Riza where , still are fixed on an aluminum frame !

Tamango 2

----Ursprüngliche Nachricht----
Von : amelyachtowners@...
Datum : 26/06/2018 - 18:16 (MS)
An : amelyachtowners@...
Cc : jamescromie@...
Betreff : Re: [Amel Yacht Owners] Isolated grounding question - solar installation



I believe that if you assembled an expert panel to discuss this issue consisting of Nigel Calder, Henri Amel, Joe Dwyer (lightning expert), the best marine surveyors, and others, the shining star on that panel would be Henri Amel. Sure, that belief is personal and could be argued. Maybe what cannot be argued on this issue is that more design, effort, and money is has been but into each Amel Yacht during the last 20 years than any other builder of production pleasure yachts. I personally have had issues with a few Nigel Calder doctrines, but I can understand when he write these as "one-fits-all-boats" he certainly can be a little 'Off" on one design/boat.

From personal experience:
I do not believe that bonding is required on the arch of a SM anymore than its life rail, standing rigging and masts...they are not bonded by Amel, so Henri Amel agrees. My guess is, that as unpredictable as lightning is, it
almost always strikes the masts.
​BTW, ​
I am thankful for the carbon fiber masts...they make excellent lightning rods. I have twice experienced lightning strikes in anchorages where "unpredictable lightning" struck boat
with a carbon fiber mast
, and left all the rest of us mostly untouched.

Little side note: After Henri died, the management of Amel decided to add some things 
to the Amel bonding system
​ ​
like standing rigging and life rail
​. I wonder whose research they used, or maybe they thought it is easier to bond, than to explain? I will never know the answer to that question.​

EARTH to the Arch & Frames:
I do not think that DC Negative is attached to the solar panel frame. How do you know that it is? Home solar installations normally require a "safety ground" a/k/a EARTH attached to the frames, then to EARTH. It is possible that some expert, somewhere, has googled this point and relayed it to you. Remember DC Negative is not EARTH, and your Amel does not have an EARTH circuit for DC Voltage. I believe that the arch is isolated from DC Positive and Negative, and if so, connecting the Arch to Amel bonding is OK, but probably not necessary. Probably more important is dissimilar metal corrosion when using stainless steel and aluminum in the same construction. I know this is probably not the case with your Emek Arch, which is stainless, but, do your panels have aluminum frames?


CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus

Amel School
720 Winnie St
Galveston Island, TX 77550

+1(832) 380-4970

On Tue, Jun 26, 2018 at 7:39 AM Nick Newington ngtnewington@... [amelyachtowners] <amelyachtowners@...> wrote:

Re lightening: this subject opens a can of worms with lots of theories. You should read Nigel Calder’s book. He explains the various ideas. Personally I am not at all convinced of one argument nor another. 

 My view re potential electrolysis is that on balance every metal fitting should be linked to the bonding system, but the important ones are the sea water exposed ones like through hull fittings and sea water pumps. The idea being that there is no potential difference between any one piece of hardware and another. 

Nick (Amelia hull 019 AML 54)
On 26 Jun 2018, at 13:02, James Cromie jamescromie@... [amelyachtowners] <amelyachtowners@...> wrote:

Thank you for your input and experience. I waS also not originally planning to bond the frame. Your points about the other metallic fixtures are good. However, I wonder about how this situation may be different considering the arch is holding a high voltage system. My feeling is it should not matter as long as the solar power circuit “-“ is well insulated from the housing. 

What about the potential risk related to lightening? Is this at all relevant?

Pardon my ignorance!


On Jun 26, 2018, at 3:42 AM, divanz620@... [amelyachtowners] <amelyachtowners@...> wrote:



We have a stainless arch with solar panels and a wind generator on a separate mount, but none of this framework is connected to the bonding system.
I'm not sure that this is necessary.
None of the other stainless structures on the boat are connected to the bonding system.
The masts and rigging aren't, neither are the rails around the boat, nor the bow roller fitments.
I'd be interested to know what others think about this
Olivier ? Bill R ? Bill K?
Elyse SM437

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