Fused / Switched Negative DC, EU vs. US

[batkins61]

Apparently, in Europe, the standard requires that the negative connection to the battery be switched and that the negative to the main panel be fused. However, this is apparently in violation, or at least counter to recommendations to the ABYC standard (this was according to a marine electrician who I had inspect my electrical systems recently).

My 2003 Beneteau, although manufactured in Marion, SC, was build to European standards, and has both the negative cutoff switch and fuse. His recommendation was to eliminate both (and repurpose the negative cutoff switch as a start/house bank parallel switch for emergency starting from the house bank).

I have not read either standard, but since this came up in another recent thread, I wanted to know what the consensus is on the forum before I begin rerouting cables.

Btw, I wanted to thank everyone who responded to my recent thread for information on chargers, etc. It was a great discussion and extremely informative! I really appreciate the wealth of information I'm getting from this forum. You guys are great!

[capn_billl]

Since one of the big items on a boat is corrosion, and the negatives are usually grounded, as are the anode, wouldn't having switched negative affect the anodes?

[senormechanico]

My boat's not fused in any of the negatives (Built in Denmark), but originally there were several places where ALL the negative returns were connected with 1/4" spade lugs.
After replacing all of them with ring connectors and screw terminals, my zinc usage dropped by 90% !

[AnchorageGuy]

Unfortunately all too often a Surveyors "opinion" gets written into a survey and the cost immediately begins to add up. My recommendation would be to not change anything unless you have now been required to as a result of the comments on a survey. There is nothing inherently wrong with your current installation and keep in mind the even ABYC is a "standard", as you have stated, and not a requirement. If the system was designed and built by the manufacturer correctly then a change should be because you want to and have the extra time and money to spend rather than feeling that you HAVE TO. IMO. Chuck

[Blue Stocking]

Not intending to slight your question, but this subject has been discussed so many times, that I have come to believe that Europian atoms are different from American and Canadian atoms.

[capn_billl]

Originally Posted by Blue Stocking

Not intending to slight your question, but this subject has been discussed so many times, that I have come to believe that Europian atoms are different from American and Canadian atoms.

You could be right about that, Ammonia changes from a NON-flamable to a flammable gas as it crosses the US/Canadian border.

It must be nice to be able to legislate laws of physics like that.

[David_Old_Jersey]

Originally Posted by Blue Stocking

Not intending to slight your question, but this subject has been discussed so many times, that I have come to believe that Europian atoms are different from American and Canadian atoms.

One of the useful things that I learnt on CF was that American light switches etc are upside down (off is actually on).....potentially that will mean that I won't be learning the hard way . Potentially .

[goboatingnow]

Originally Posted by batkins61

Apparently, in Europe, the standard requires that the negative connection to the battery be switched and that the negative to the main panel be fused. However, this is apparently in violation, or at least counter to recommendations to the ABYC standard (this was according to a marine electrician who I had inspect my electrical systems recently).

My 2003 Beneteau, although manufactured in Marion, SC, was build to European standards, and has both the negative cutoff switch and fuse. His recommendation was to eliminate both (and repurpose the negative cutoff switch as a start/house bank parallel switch for emergency starting from the house bank).

I have not read either standard, but since this came up in another recent thread, I wanted to know what the consensus is on the forum before I begin rerouting cables.

Btw, I wanted to thank everyone who responded to my recent thread for information on chargers, etc. It was a great discussion and extremely informative! I really appreciate the wealth of information I'm getting from this forum. You guys are great!

No the RCD does not require disconnects or fusing in the negative side, but its a common setup for french built boats. Is a good idea, lets you isolate the batteries completely if you want too. SUch isolation cuts down on unwanted galvanic corrosion.

[goboatingnow]

Originally Posted by capn_billl

Since one of the big items on a boat is corrosion, and the negatives are usually grounded, as are the anode, wouldn't having switched negative affect the anodes?

European boats normally have no connection between AC earth and Dc negative. RCDs take care of the safety issues.

As to switched negatives yes its helps reduced DC galvanic corrosion, as it isolates the batteries when not in use.

Dave

[batkins61]

I found the discussion, strongly against ground isolation, pretty compelling in the SmartGauge article: SmartGauge Electronics - Battery Isolator Switch Positioning

Most of their points are in line with the reasons provided by the ABYC electrician I spoke with.

[senormechanico]

I suppose that's exactly what was happening on my boat as described above in post #3.
Instead of switches, it was just poor spade lug contacts in multiple locations.

[2007.pierre]

I think in the 80's, jeanneau use to ground the negatibe network to the backstay probably beacause an irresponsible engineer would belive that the lightning would go back to sea...to kill the sharks! On a high quality Nordic boat, everything was grounded, included the bronze through hull...Result: electrolysis everywhere. I removed all that crap, made shure that the rigging was not grounded and I made fivety thousand miles with no more problems...In central Florida where lightning is more than frequent, all boat hit where grounded...In France, the monuments are also grounded and almost everytime the lightning strike, his path is not along the copper wire but anywhere. Fusing the negative is useless since each pisitive leg is fused. Whan the boat is not atternded, the master switch is there tio avoid battery kleaks. Personnally, when the boat is not in use, I would put the main switches OFF and no charger, except for a solar panel, certainly not a wind generator that will wear out quicker and fail when youn need it.