Re: [Amel Yacht Owners] Main furler motor issue
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No parts or diagrams from the yard or its supplier (Leroy Somer) so far. Amel do recommend changing the top seal to avoid water intrusion but so far we haven't found a description on how to do that, except that it is possible to do without removing the end caps, which are "glued and near impossible to remove without damaging the casing" as per Amel.
Anyway, we gave up trying to remove the top end cap.
At the bottom end of the block there is an electromagnetic shaft break, controlled by a separate solenoid. When not energised, a spring mounted ferrous metal disc presses on a plastic disc fixed to the shaft. When energised, the magnet pulls the metal disc away and frees the shaft. There is a distinctive click noise when that happens. I think this is the first point of failure when corrosion strikes, as the corroded springs between the magnet and the ferrous disc seem to lose flex.
In the event of failure of the overall system, absence of that mechanical click coming from inside the casing maybe a tell tale.
We researched the part (ERD 500 from Warner Electric) and its maintenance and the constructor suggests the gap may need to be adjusted later in life to allow operation.
This part is easy to remove, 3 Allen screws. 1 of ours was corroded in and broke, though. I think those screws also control the amount of default pressure on the plastic disc, so it maybe useful to make a note of their position before removing them.
Next is the motor itself. 4 screws to remove 2 top plates, circlip, gear, wedge (?, clavette in french) and then 2 nuts that screw onto bolts the length of the motor to maintain the brushes element wedged in place onto the collector/commutator. Brushes are indeed spring loaded and a pain to put back.
Around the rotor, there is a metallic tube with the permanent stator magnets glued on the inside. On ours half of the magnets were unglued and all over the place. Hence the motor failure. Did they become unstuck because the failed shaft break prevented rotation and the rotor magnetic field snapped the permanent magnets off? Or is it just direct failure? I don't know.
So we epoxy-glued them back, cleaned all the dust away, remounted everything but the break, tested on a pair of car batteries and it rotated happily. The break wouldn't snap, though, so had to change the springs, adjust the gap, and remount it with the right amount of pressure to let it do its job.
We intend to change the break part altogether for a new one, as a better solution. We also intend to carry a spare complete system bought from Amel for peace of mind, when we can source/afford it ($3k?).
We knew next to nothing about DC motors when we started, so we would be very happy to hear comments about what we found/did. For instance I don't understand why the break is controlled by a different relay/solenoid. They seem to be on at the same time/voltage.
We got help of a local guy in Morocco. He was fantastically helpful if not 100% orthodox in his methods.
We'll try to annotate pictures and make a document in the files section. We'll carry on researching the changing of the top seal. Stay tuned.
Amel 54 #122
Porto Santo, Madeira, Portugal
On Tue, 17 Oct 2017 at 16:03, 'Mohammad Shirloo' mshirloo@... [amelyachtowners] <amelyachtowners@...> wrote: