The existing electrical installation was entirely 240v
based, excepting the engine electrics and starter which were 24v. As Janna was
used essentially as a houseboat, and then latterly as a holiday home, the
assumption had been that she would always be plugged into a shore line. There
was (still is) an air-cooled 5kW Honda 240v generator in the engine room, as
yet untried by us. Going on what the previous owner said and on my own
experience with such a generator, the adjective I would imagine that would be
used to describe its running characteristics would be
Noisy!
I decided, basically to reduce the amount of
rewiring and installation work, to keep Janna essentially a 240v supplied
vessel. The fridge/freezer, the existing lighting, the bilge pumps and the
shower sump pump were 240v, so no point financially in replacing those with 12
or 24v units.
The engine starter of course was, and still is, 24v based,
as was the alternator - which had been used solely for charging the starter
batteries. The starter remains at 24v with, initially a DC-DC 12/24 converter
to charge the starter batteries. This however proved unsuitable to maintain the
starter batteries and has since been replaced with a 240v/24v battery charger.
The alternator was replaced with a 12v/150A unit.
As the system required
a shore line to be connected and as I had already decided to maintain the main
systems at 240v, then a decent sized 12v battery and inverter was required. Why
12v some people have asked - the answer is because it is what I am used to, and
perhaps more importantly, equipment for 12v is often more easily obtained than
for 24v. Consequently a bank of 8 x 6V/ 225Ah batteries were installed feeding
a Victron Multiplus 3kW inverter/140A battery charger. This has proved capable
of powering all the equipment and lighting currently in use.
The Honda
generator I have still yet to test, but I feel that it may well be replaced
with something more modern and quieter! - time will tell...
| The 8 x 6v battery bank | The Sterling Alternator controller |
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| The new 240v consumer unit and RCD | The shore line isolating transformer |
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| The Victron Inverter, 12v distribution board, battery isolation switch and the DC-DC 12v/24v converter | |
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