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SM 316 with 8 100Ah battery ...
Le 30/10/2020 à 06:42, eric freedman a
Hi Jean Luc,
What model Amel do you have?
Sm 376 Kimberite
On October 30, 2020 at 1:21 AM
"jlm@..." <jlm@...> wrote:
On CottonBay I messured in the past the bow thruster curent :
Le 29/10/2020 à 21:46, Karen Smith
via groups.io a écrit :
Our SM#160 bow thruster draws about 485
Amps when it is running. The exact power calculation is
complicated because the voltage is not steady at 24 volts, but
drops quickly, and significantly, under this load. The reason
the wire looks undersized by standard calculations is that it
operates on a very short duty cycle, so heating of the wire is
minimal. If you were to try to push 500 Amps through that
wire for an hour, you'd have a real problem.
At least on our boat, the "bow thruster" cable carries all the
24V power to everything forward of the forward saloon
bulkhead. Mast and genoa furlers, cabin lights, nav lights,
We have fused our battery bank in two different ways, and both
worked well. Keep in mind we have a bank of 4 pairs of
batteries, smaller than yours which I believe is 6 pairs.
Our batteries were first fused with four 125 Amp rated battery
terminal fuses, one on each 24V positive, for a total of 500
Amps. With 6 pairs of batteries you'd end up in the about
same place with 80 or 90 Amp rated fuses. When we changed
battery brands, the terminal fuse holders no longer fit under
the battery box lid, so we switched to a singe 500 AMP
ANL-style fuse. Never have any of these tripped.
We have also reworked the whole 24 volt distribution system so
EACH of the wires leaving the battery box has a fuse
appropriate to its ampacity, and the switches now interrupt
current to everything except the bilge pump circuit. To me
this is a really basic safety issue. If there was ever to be
an electrical fire on the boat, or a piece of runaway
equipment, I need to know I can shut off the power to everything
On the boats I have seen, Amel was very inconsistent about
what wires they connected to which side of the main switches.
On our boat, only the battery charger, bilge pump, and "always
on 12V converter" were connected to the unswitched side. I
think on later boats they just ran out of space on the stud on
the switched side, so were forced to move wires to the