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Glenn Ashmore Glenn Ashmore is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 329
Default Can an alternator be to big?

This thing uses a J-180 mount same as the Leece Neville so it will basically
be a drop in. Also supposed to generate less heat so the duct work I
installed for the LN should be more than adequate.

The weird thing about this alternator is that the primary magnetic field is
from the permanent magnets on the rotor so as long as it is turning it is
generating power. The way you turn it off is to run the field current in
reverse to cancel out the magnets. That greatly increase the efficiency but
means it can't use a normal external regulator.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"GBM" wrote in message
...
There used to be a manual alternator regulator called an Automac, sold by
Weems & Plath - This allowed the alternator output to be manually
adjusted.
These are no longer sold, but perhaps someone else sells something like
that? Or perhaps drive it through a clutch that can be disengaged and
keep
a smaller alternator in service?

I can understand that the price is attractive, but I would be careful with
that beast! Unless of course, if you plan on doing some welding
Usually
better to have multiple smaller units. Ventilation and cooling may need
to
be addressed - will you get enough cooling in your engine room as compared
with the intended installation for those units?

BUT, if you have the HP to drive it, it does sound like an interesting
unit - especially the low speed output.

GBM

"Glenn Ashmore" wrote in message
news:ulwug.165$ok5.148@dukeread01...


No real problem there. Because if the higher efficiency the HP charts
say
it will take less power than the 200A Leese Neville that is in there now.

I
have 4/0 to the 850AH bank and the inverter and 2/0 to the breaker panel.
At idle speed it will theoretically put out up to 240 amps which will

cover
the 225A the battery bank needs in bulk mode with a little left over for
house loads.

The alternator is an Eco Tech 305. Apparently they are becoming popular
with the commercial fishing boats in the NW. The regulator is set for

14.4
volts so while it may take a little longer in bulk mode it will be just
right for absorption. I just need to figure a way to turn it off when
motoring through a couple of days of no wind. Not a good idea to hold a
fully charged battery at 14.4V for very long.

Go2Marine has them on their site listed at $2K. The city is asking $375.

I
think I am going to take them up on it. :-)


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com