Jules,
Without the basics it's hard to deturmine what you need but as far as in general here's my input
> it seems better to use a diesel generator to produce DC with a large enough capacity to power the electric drive motor(s) directly for the times when i need cruising speed.
> this will let me get away from the "usual" AC output genset that has to be converted to DC before being sent to the motor controllers(s).
Direct DC is preferred; it eliminates inverters to DC and simplifies the system. I have a AC genset and would much prefer a DC for simplicity however it really depends on the size of the system and whether the cost is justified for the more expensive DC genset. My genset has a manual variable output to manage the charging of the batteries. Something I have to pay attention to, the new gensets have an automatic start/stop which I'm a little leery of.
> add a battery bank of the same DC voltage as the generators output and the motor controllers input.
Correct.
> add a single phase battery charger for shore power top up.
I'm not sure why you would want to go to single phase, a 240V will give you more amperage, a quicker charge and smaller wires. Depending on the battery type you also want a multistage charger.
> add a 230 VAC output inverter to run the onboard appliances.
Correct. I'm assuming this is a European boat. 120v for US system.
> if i can get my hot water from the genset that about finishes the system?
A genset with a heat exchanger is what I have and works great. I also have a 10 gal. HWH for the storage and heating during shore hookup.
> if i am heading in the right direction, i will bore you with the boat details, but i thought i would get the theory right before moving on to the practice.
Also plan on several switches so that you can't operate the genset and shore power at the same time as well as the inverter only when operating the genset.
> thanking everyone in advance
Hope it helped.
Steve in Solomons MD
Lagoon 410 SE
Tuesday, May 1, 2012
RE: [Electric Boats] Re: new system from scratch, am i on the right track please?
[Electric Boats] HELLO
Monday, April 30, 2012
[Electric Boats] Re: Hello
The statement that it takes 750W to displace 1tone is true but will bring you to hull speed in no wind conditions
--- In electricboats@yahoogroups.com, "hardy71uk" <p0054107@...> wrote:
>
> boats are different to airplanes because although the formulas are the same there are different practical limits . For example in boats the larger the prop the more efficient ( that is at slow and medium speed ; the normal electric range) thats why , as I understand it, Larry recommends beginning with the biggest propellor that has adequate clearance .Find the power needed for the desired performance and then select pitch ,gear ratio and motor to match.
>
> Chris S
>
> --- In electricboats@yahoogroups.com, Daniel Michaels <nov32394@> wrote:
> >
> > Thanks for the input Larry.
> >
> >
> >
> > I am more familiar with airplanes and props but I think they work about the same.
> >
> >
> >
> > We first take the max rpm we are running plug that into the chart to
> > find out how fast the plane will go with each pitch. Shorten or lengthen
> > the prop to let the engine run at max rpm. The pitch tells you how fast
> > the plane will travel.
> >
> >
> >
> > I am not sure the Triton was designed around an Atomic 4. I think an
> > Atomic 4 fit into the general usage for the Triton. The Atomic 4 went as
> > high as 20 hp. When only 10 to 12 could really be used. Running the rpm
> > only to 1500 gave you 11.9 BHP. It has a 13 inch 2 blade prop. So if I
> > had 12 hp available at 1500 rpm it would do the same thing. If I found
> > out what hp the electric motor had at 1500 rpm I should know if it will
> > turn the prop. Alternatively I could shorten the prop and turn a higher
> > rpm. I could also go with a 3 bladed prop. The electric motor I am going
> > to use is 13 hp @ 48v same as the Atomic 4. Only this will far
> > outperform the Atomic 4.
> >
> >
> >
> > This is what I have so far. this is from limited knowledge but I am learning every day.
> >
> >
> >
> > It takes 1 Kw per ton of displacement.
> >
> > 750w = 1 hp
> >
> >
> >
> > 36 v 140 amps 1400 rpm 3500 watts E Teck motor.
> >
> > comes to 3500/750=4.7 hp * 2.5 conversion factor to compare it to the
> > Atomic 4 = 11.75 hp. @ 1500 rpm the Atomic 4 is 11.9 Very close.
> >
> >
> >
> > 48 v 180 amps 4800 rpm 9800 watts E Teck motor.
> >
> > comes to 9800/750=13 hp * 2.5 conversion factor = 32.5 hp but at 4800 rpm if I cut the rpm in half I am at 16.25 The Atomic 4 is 16.2 @ 2000.
> >
> >
> >
> > At 36v 3500 watts the 1 kw per ton works out very close to a Triton at 4 ton.
> >
> > At 48v 9800 watts /2 = 4900 it comes out in my favor with a half ton to
> > spare and that is at half throttle. If I use a reduction drive on the
> > 48v of 2 to 1 I am out performing the Atomic 4 at every level.
> >
> >
> >
> > 36v at 140 amps run wide open
> > 6 * 260 Ah batteries / 50% = 780 usable Ah. 780 / 140 amps = 5.5 hrs.
> > run at half throttle or less and you will go much farther same as if you
> > throttled back on the Atomic 4.
> >
> >
> >
> > 48v at 180 amps 8 * 260 Ah batteries / 50% = 1040 usable Ah. 1040 / 90
> > (180/2) amps = 11.5 hrs throttle back even more and even I need some
> > sleep.
> >
> >
> >
> > Is any of my math correct. I gave it my best shot.
> >
> >
> >
> > Dan
> >
>
Re: [Electric Boats] Electric Boats messages being cloned to a blogsite
This is a test post. Please accept apologies and ignore.
-Moderator
Re: [Electric Boats] Sail Boat project
Dovetail Designs
1889 US Rt. 9 #43
Toms River, NJ
732-244-8640
To: electricboats@yahoogroups.com
Sent: Monday, April 30, 2012 7:02 PM
Subject: Re: [Electric Boats] Sail Boat project
--- In electricboats@yahoogroups.com, Jeffrey Gascho <dovetailnj@...> wrote:
>
> Nick,
> Â
> In a Macgregor?
> Seems kinda like putting a Ferrari engine in a mid 80's Chrysler sedan, no?
>
>
> ________________________________
> From: Nick <nstoika@...>
> To: electricboats@yahoogroups.com
> Sent: Saturday, April 28, 2012 4:15 PM
> Subject: [Electric Boats] Sail Boat project
>
>
> Â
> I'm selling a 25 feet McGregor that has been a "project" for an electrical boat......due to personal issues I moved to Europe so the Boat is still in "project" stage in Lake Tahoe California.
> nstoika@...
>
[Electric Boats] Hello
Kindly help me view this Property Click Here
Let me know what you think about it.
William
Re: [Electric Boats] Sail Boat project
It's about hull speed not about fast......sail boat have a very good hull speed.
--- In electricboats@yahoogroups.com, Jeffrey Gascho <dovetailnj@...> wrote:
>
> Nick,
> Â
> In a Macgregor?
> Seems kinda like putting a Ferrari engine in a mid 80's Chrysler sedan, no?
>
>
> ________________________________
> From: Nick <nstoika@...>
> To: electricboats@yahoogroups.com
> Sent: Saturday, April 28, 2012 4:15 PM
> Subject: [Electric Boats] Sail Boat project
>
>
> Â
> I'm selling a 25 feet McGregor that has been a "project" for an electrical boat......due to personal issues I moved to Europe so the Boat is still in "project" stage in Lake Tahoe California.
> nstoika@...
>