Saturday, January 3, 2015

Re: [Electric Boats] running the motor on genset

 

That is great news !! 
 
I had been told that the charging needed to be done with the dc motor off, and a battery pack in the system as a buffer.  Now the decision can be to carry a small genset, instead of a second pack.  I don't like the idea of the genset running while cruising, but maybe one of the newer ones would work quietly enough.  Harbor Freight budget here, but they do show a couple at a comparable cost/weight comparison to my best price for a set of batteries, at about $ 300. for four 27 size.   Generator maybe a bit less than pack weight, and definitely easier to shift for balance in a 17 ft. cabin cruiser.
 
Thanks Larry,  Cal
 
 
 
 
 
 
Sent: Friday, January 02, 2015 5:14 PM
Subject: Re: [Electric Boats] running the motor on genset
 
 

In the late 60's, I was stationed on a sub tender in San Diego who's propulsion system was diesel/electric.  A diesel powered generator powering a DC motor directly, no batteries.  The reason for using this system was to eliminate the reduction gear set that would normally have been installed.  I was always told that the Navy did not buy ship reduction gear sets as they were extremely expensive.  And instead, they leased them.
Using the DC motor eliminated the need for any reduction gears.
 
Sent: Friday, January 02, 2015 5:00 PM
Subject: RE: [Electric Boats] running the motor on genset
 
 

This is what I wanted to confirm.
 
Martin

To: electricboats@yahoogroups.com
From: electricboats@yahoogroups.com
Date: Fri, 2 Jan 2015 16:56:00 -0500
Subject: RE: [Electric Boats] running the motor on genset

 
 

In an earlier post, you (or someone else?) said that motors are known to draw more than their rated horsepower on start-up.  That is true if applying full voltage when the motor is at a dead stop.  For example, the blower in your furnace is powered up by applying full power via a relay.  In your case, however, you will be slowly throttling up.  You can easily keep the power below what the generator can provide as the poster below suggests.

 

From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com]
Sent: Friday, January 02, 2015 4:01 PM
To: electricboats@yahoogroups.com
Subject: RE: [Electric Boats] running the motor on genset

 

I understand that, but what about starting on genset only(without batteries)??

 

Martin

From: no_reply@yahoogroups.com
To: electricboats@yahoogroups.com
Date: Sun, 28 Dec 2014 12:29:10 -0800
Subject: RE: [Electric Boats] running the motor on genset

 

Just don't run them up over 8kw each and it will work.

 

__._,_.___
Posted by: "cal" <h20dragon@centurytel.net>
Reply via web post • Reply to sender • Reply to group • Start a New Topic • Messages in this topic (20)

.

__,_._,___
Posted by at

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)