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240v Wiring

All wiring of marine 240 volt systems in UK, must be examined and
certified by an AC-qualified, licensed marine electrician to UK Institute of
Electricians standard. I am not qualified to do this. If this certification is
not completed then you and your crew could be at risk, and you will have
almost certainly nullified your insurance, and your boat will be at risk of
fire started by electrical faults. You could also be charged with criminal
negligence or manslaughter with subsequent litigation for damages. You
could even be arrested and held pending further action. Here endeth the
Lesson.
My friend’s S110 “Sirocco” had an appalling 240 volt system installed by
some amateur, before they purchased. It consisted of a fixed input socket
for attachment of the shore power, connected to an extension type lead
with four 13 amp sockets screwed to a bulkhead in the aft cabin. At this
point there were a number of wires with 13 amp plugs on them, so that
one or more of the following could be plugged in. 1. A further extension
lead with four sockets fixed to a bulkhead in the saloon. 2. The immersion
heater. 3. A cheap battery charger.
The system was unsafe because it did not comply, it did not have an RCD
or any MCBs and further, if the battery charger was in operation, then the
shore power earth was connected to the ships 12 volt negative and thus
to the anodes and stern gear. This type of wiring apart from the risk to
life, and legal implications, greatly increases the possibility of rapid de-
zincification (Electrolytic Corrosion) of the anodes and external metal
stern gear, while connected to the mains afloat.
So we have installed a protected system with Galvanic Isolator, RCD and
MCBs. See below for clarifications of these terms. The design of this was
created with reference to the diagrams and information on the Safeshore
Marine UK website as detailed here http://safeshoremarine.com/ this was
very helpful.
Safeshore Marine also supplied the Galvanic Isolator with Indicator, we
used Model GI 70 sm, at a delivered cost of £95.94, see here http://
safeshoremarine.com/buyitnow.htm

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