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it sounds frm donald's thread below that this wonderful boat may have come to grief, very sad, tho at least nobody injured as far as i know.


<A target="_blank" HREF=http://www.qei.co.uk/spark.html>http://www.qei.co.uk/spark.html</A>


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Sadly I think you are right....

<A target="_blank" HREF=http://www.mcga.gov.uk/c4mca/mcga-dops_pr_newsroom-press-releases-release.htm?mcga_news_id=2588&month=7&year=2004>http://www.mcga.gov.uk/c4mca/mcga-dops_pr_newsroom-press-releases-release.htm?mcga_news_id=2588&month=7&year=2004</A>

A beautiful and innovative boat. I hope he builds another!

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If it is the same boat then it is a real pity as it was a work of art and a joy following its build on the internet site.

I trust all those putting small portable generators on their boats (a current thread on MoBo again) will take note and also remember that apart from the petrol and CO risks, those generators normally have floating neutrals, and also be aware that RCD's do not always reliably break in floating neutral systems. I would not have one on any boat I was on.

John

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Ok, Now i am concerned.
I don't know all that much about these generators, hence the post on MoBo. So what is a 'Floating Neutral System', And if i was to buy a RCD unit from B&Q, will it not make any difference?



<hr width=100% size=1><A target="_blank" HREF=http://arweb.co.uk/argallery/alistair?&page=1> My Pictures, Please take a Look.</A>
 
Normally, the neutral is tied to earth at the source (ie power station). This makes the neutral safe and the live dangerous, which is why in the UK we switch the live wire in any appliance. In many portable generators, the neutral floats and I believe the answer is to connect it to earth <font color=red>but first check that this will not damage the generator</font color=red>.

RCD cutouts work by measuring any imbalance between the current flowing in the live and neutral wires. Any imbalance is caused by a fault or leakage to earth, which could include a person receiving a shock. If the imbalance exceeds about 20 milli Amps the RCD trips open to protect the downstream electrics from faulty conditions.

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Alistair

I think that most of the small ones are all floating neutral, but certainly the 1000EU, 2000EU Honda ones are.

With a floating neutral the neutral conductor is not grounded. That means that the neutral has voltage on it all the time when the generator is running, whereas in the normal 3 wire phase line only live system in your normal shorepower or house the neutral is earthed and at near enough to zero potential. That is not too much of a safety problem when the generator is used to power a single appliance but can be when it is plugged into a distribution system such as on a boat, caravan, etc. For example, any appliance plugged into a bulkhead outlet, for example, will still be live (but not operable) when the bulkhead outlet switch is off.

The normal requirement on a boat (and everything else) is when you have shore power connected your neutral is grounded back in the marina's supply on shore and not on the boat. When the shore power is disconnected then your neutral is supposed to be grounded on the boat if there is an ac source on the boat such as an invertor or generator - this is normally done automatically by the shore/ship switch on the boat or some invertors do it automatically. Obviously this arrangement is not easily possible when using a portable generator whether floating neutral or not if it is plugged into the boat's shore power connection.

There have been tests with RCD's put on the outlets of floating neutral generators (the ones I saw the results of were from Canada) and for reasons that were not explained, the RCD's did not always work reliably. I have been told by people in a number of different countries that they are banned on many construction sites, especially if used to power more than one appliance eg a drill.

They are also a carbon monoxide hazard and I have seen reports of deaths in the USA from their use on boats.

After alot of hard words above, we all know that many are used on boats and there are actually not alot of accidents in practice. In the end it is personal choice, as long as that choice is made with some knowledge that there may be some extra risk. In my own case, after alot of temptation as they are very convenient, I would not have one on board.

John

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Thankyou and Tome very much for your honest replies.

I think we all learn by our own or each others mistakes. But unfortunately this has been a massive and terrible mistake when it came to refuelling.
Refuelling i can control, But regarding the earthing of the machine, i need to make sure i get right, or else i simple won't use it. The shore power was fitted by the dealer not a factory fit, and wether its earthed to the boat, ijust don't know.
The actual generator has an earth point on the front of it, so i can certainly earth it that way, But earth it to where??? I did read an old post on PBO a few week ago before buying it, and someone said connect a wire and earth it into the water!! Is that right, sounds odd to me.



<hr width=100% size=1><A target="_blank" HREF=http://arweb.co.uk/argallery/alistair?&page=1> My Pictures, Please take a Look.</A>
 
Hi Alistair

Grounding the frame of the generator, while desirable, will not normally make much difference as the generator will be grounded anyway through the earth conductor in the cable from it to the boat's inlet socket - but obviously not if the generator is running but the boat is not plugged into it.

However, that does not correct the neutral not being bonded to ground matter and for a portable generator it is not easy to fix it. At <A target="_blank" HREF=http://www.schneider-electric.ca/www/en/products/stab-lok/Gen_Panels_Appl_Note_EN.pdf>http://www.schneider-electric.ca/www/en/products/stab-lok/Gen_Panels_Appl_Note_EN.pdf</A> is a very good Schneider Electric Application Note for panels for stand by generators - it is American but from a quick read appears to be generally correct for other places with the mains supply being grounded neutral as in UK. It talks about both floating neutral and bonded neutral systems for standby genertors for houses, but I think one can see that the same applies on a boat with the service point being the marina supply. From it, it can be seen that the complications with handling a floating neutral generator correctly make it impractical to implement the requirements for just a small portable generator on a boat and if such a generator is used it would be run without going to all the trouble described.

Again, in the end, I am not saying lots of people are going to be electrocuted or burnt - just that their use reduces the level of safety on the boat by, in my opinion, an amount worth mulling over. Probably a big thing in improving the safety of them when used on a boat is just being aware of that risk and then taking care.

John

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Sad to hear the loss of such an attractive boat, but the loss reinforces the primary safety rule of any petrol engined boat: NO NAKED FLAME on board when fuel tanks are to be opened, and for at least 10 minutes after.

Thank goodness the crew got away safely: petrol fires by their nature are explosive.

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