SMALL BOATS ELECTRICAL INSTALLATIONS

Well you can't connect to any metalwork if the craft is not made of metal can you.

Z.

electrical.theiet.org/.../marinas-and-similar-locations.pdf

The metal kettle in the boat would qualify.

But in general the cases of shore power and generated on board are very different. Only the shortest of voyages will be made while plugged in, and I suspect it is almost never the dno who makes any such connection.

It will be the small/ medium boatyards dealing with narrow boats and so on that are most likely to fall foul of this rule and maybe private moorngs at the ends of gardens on inland waterways. And probably most likely for the saturday lad  to throw the extension lead much as you would a mooring rope when a boat pulls in and occasionally miss and splosh it  into the water.

Oddly only last summer we hired a boat on the Caledonian canal and the number of caravan style hookup leads flapping about  in the elements and drooping into the water mid span was something to behold. Lots of RCDs in clear plastic boxes, so there is ADS, but it still feels more continental than I am used to in the UK.

Mike.

Mike

Are you sure Mike? In that case use a plastic bodied auto jug kettle.

"A risk associated with an electrical supply to a craft at a marina includes the possibility of an open circuit fault of the PEN conductor were a PME supply to be used. This would raise the potential of all metalwork (including that of the craft, if connected) to a dangerous level above true earth and hence the connection of a neutral conductor to the metal body of a boat or caravan is specifically prohibited in legislation (Electricity Safety, Quality and Continuity Regulations (ESQCR) Regulation 9(4))."

Z.

And the "Distributor" will not be connecting his combined earth and neutral to the kettle anyway.

rotective multiple earthing

9.—(1) This regulation applies to distributors' low voltage networks in which the neutral and protective functions are combined.

(2) In addition to the neutral with earth connection required under regulation 8(3)(b) a distributor shall ensure that the supply neutral conductor is connected with earth at—

(a)a point no closer to the distributor’s source of voltage (as measured along the distributing main) than the junction between that distributing main and the service line which is most remote from the source; and

(b)such other points as may be necessary to prevent, so far as is reasonably practicable, the risk of danger arising from the supply neutral conductor becoming open circuit.

(3) Paragraph (2)(a) shall only apply where the supply neutral conductor of the service line referred to in paragraph (2)(a) is connected to the protective conductor of a consumer’s installation.

"(4) The distributor shall not connect his combined neutral and protective conductor to any metalwork in a caravan or boat."

Z.

Most small boats that I have been involved with have gas stoves to boil water, not electric kettles. Or larger craft may have a sold fuel stove.

Z.

Yachts have sacrificial anodes to prevent corrosion of props and structural nuts and bolts.

I was told its not a good idea to attach the negative side if the 12V system to the metalwork of a yacht.

Good chance of damaging the on board navigation equipment and other electronics.

The prevention of corrosion on boats is a complex subject and there are many differing views.  A search on a  web site like https://forums.ybw.com/index.php?forums/practical-boat-owners-reader-to-reader.13/ is a good place to start.

The hull anode on my 36 foot yacht is (as most) connected to the negative of the dc system.  It generally has to be as it is protecting the stern gear (bronze prop on a stainless steel shaft which in turn is in metal to metal contact with the engine.  The battery system negative connects to the engine block for the starter motor to work! 

A common cause of corrosion in marinas is from the shore supply.  At worst if the supply is illegally connected to a TN-C-S supply corrosion can be rapid and extreme.  Such a connection is also dangerous.

One of the standards I quoted ISO 13297 (or EN ISO depending on which version are reading) used to allow you to keep the boat dc system electrically separate from the ac shore supply.  This was so in the 2000 standard.  However, it changed in 2012 and as far as I know it is still the same, so you now have to interconnect the two systems at the earth bar - I and many others don't like this so my boat still has separated systems

Zoomup  mind your propeller doesn't fall off.

Why would it? In my small GRP hulled boat, or my wooden hulled boat there will be no connection to metal and any mains at all. The outboard motor is always tilted so that the prop is out of the water when I am not using my boat. Do you think that the rain may rot the prop?

Z.