Re: A54 bow thruster directly to battery or through main switches?

James Alton


   This is very interesting since the service disconnect switch looks very similar to the Ecans Soderep S190 installed on my Maramu.  I recently ordered  a replacement from Amel for my original engine disconnect switch that looks identical to my original switch.  I was having engine starting problems that I traced to an excessive voltage drop at the engine disconnect switch.  Not having a spare aboard at the time, I opened up the switch expecting to find burned contacts but actually they are in almost perfect shape.  The problem stemmed from the phenolic breaking around the bearing surface supporting the handle shaft which caused the contacts to sometimes not line up properly.  Some epoxy restored the function of the switch and we used it without trouble for the rest of last season.  I am mentioning this because I have read that others have had problems from these switches at times and at least in my case the issue was repairable and the switch is not hard to open.  I will of course now install the new switch and keep the old one as a spare.  It would be great if I could install a third switch like this for just the bow thruster loads.

     Would you by chance know the exact model of the switch shown in your photo?  I would also be interested to know either the wattage/horsepower rating of the Amel 54 bow thruster to estimate the amperage draw to compare to mine.  My Maramu has the bow thruster wired directly to the batteries which means that regardless of the switch position the circuit is hot.  I would very much like to install a reliable service disconnect switch along with a fuse to better protect this circuit.  I considered the S190 but was concerned about the 250-300 Amp continuous rating shown by the manufacturer.  The peak load of this switch is however 10X higher so maybe it is sufficient due to the short duration of use?  Would anyone know if this model switch would be sufficient for the approximate 4-500 amps that my bow thruster should draw at 12V? I am bringing a clamp meter to the boat soon to get a more accurate measurement.



On Feb 7, 2020, at 5:32 PM, CW Bill Rouse <brouse@...> wrote:


Yes, in other 54s there is are 24v cables +/- coming from the main switch. In this photo of an unmodified Amel 54 the positive cable from the switch to the Bow Thruster box in the bow is a black cable. You can barely see it. It is under the 110 A Alternator red cable. I believe that some of the 54 switches are wired differently. Please let me know if the photo below agrees with yours.

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
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On Fri, Feb 7, 2020 at 3:59 PM Scott SV Tengah <Scott.nguyen@...> wrote:
As the title suggests, does the a54, wired as amel intended, place the bow thruster power wires directly to the battery or are those cables connected through the main battery switches? 

We're having some intermittent issues with ours and trying to rule everything out. Thanks .
2007 A54 #69
SV Tengah

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