Actually, once you get past the 50V range, the ABYC TE-30 considers the safety issues to be that same: "This technical information report addresses AC and DC electrical systems used on boats alternating current (AC) systems operating at more than 300 VAC, but less than 1000 VAC, and direct current (DC) systems operating at more than 50 VDC but less than 1000 VDC, including battery banks, motors, and controllers for the purpose of propulsion."
Some have asked "why 50V (or less)?". ABYC states this as a definition for "Potentially Hazardous Voltage - Voltage levels that can harm humans through electric shock (see UL 2231 Personnel Protection Systems for Electric Vehicle (EV) Supply Circuits: General Requirements and UL 2202 Electric Vehicle (EV) Charging System Equipment). DC voltages over 50 V and all AC voltages are considered potentially hazardous."
So there's really not a reason to stop at 144V, though ABYC does suggest that it should be possible to break battery banks down into groups of no more that 48V banks (nominal) for servicing. If you can find the appropriate motor, controler and charger, then going to higher voltages reduces the amperage for the same current. In the EV world, 144V, 156V, 192V and even 288V components are fairly available. Net Gain, evnetics and Zilla all make DC controllers that handle 300V+ with peaks greater than 1000A.
For a big boat like the Hatteras, I would be looking into DC motors like the Warp-9 ('cuz I have one in my garage) or the Warp 11 or even a Warp 13. The regular Warp motors max at 170V, but the Warp 11 in available in HV with interpoles that is rated to 288V, though the max torque is actually lower for the HV model. The Warp 13 puts out 100 ft-lbs of torque at 300A and 440 ft-lbs at 1000A. Of course the 1000A is not a continuous rating, but I doubt that the IC engines that are coming out produced anything near those numbers. Anyway, these components are well proven with 100's of thousands of highway miles of EV usage, so the reliability is there. Installing them is straight forward, they're just bigger versions of the DC motors that have been used by members here. This could be just off the shelf stuff with very little fabrication or re-engineering. Easy to get parts or spares, why reinvent the wheel (so to speak).
The AC motors in use by EVs tend to be lower voltage systems, the Curtis AC controllers max out around 120V and they tend to rate the controllers in 2 minute ratings rather than continuous, so I don't think that the typical "heavy duty" AC-50 is up to the kind of loads that you should expect.
Anyway, that's how I would start digging into the project. Your results may vary.
Good luck and keep us posted.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@yahoogroups.com, brucekroll@... wrote:
>
> LOL Not what we have in mind!
>
> On Mar 6, 2012, at 3:51 PM, "Tom" <boat_works@...> wrote:
>
> > How about 480V? Yowsa!
> > http://www.lightstream.at/hightTech.html
> >
> > -Tom
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