Author Topic: HOUSE BOAT  (Read 3762 times)

WHITEOX3

  • Newbie
  • *
  • Posts: 9
    • View Profile
HOUSE BOAT
« on: January 21, 2007, 12:49:01 PM »
Hi I am installing a Changfa 3.5 hp water cooled diesel in a house boat if I can ever get the motor and gearbox to alline up . But what I want to know is it possable to run the same type motor to a auto alternator then to a inverter for electrice in the boat. Have worked out the watts I need around 900 at full peak, but most around the 400 mark and will run less then 6 hr a day Thanks Don

ZackaryMac

  • Nova Scotia, Canada
  • Jr. Member
  • **
  • Posts: 86
    • View Profile
Re: HOUSE BOAT
« Reply #1 on: January 21, 2007, 03:37:31 PM »
WHITEOX3
 I have an alternator setup with my Kubota, and overloaded it running a block heater on my truck (the Kubota is set up as a portable(!) generator). I have a 1200w inverter hooked to the car battery the alternator is charging.
The failure was caused by overheating the rectifier (diodes). I asked a local starter/alternator Guru about why the 60 amp alternator failed,and he told me that most alternators are rated for their peak output, and cannot hold that 100% of the time without overheating. He said about a 50% steady draw would be safe.
 If I wanted a higher steady outputl, then put at least a 100 amp alternator on it.

To make a long story a bit longer, be sure if you are going to have a higher steady load on the alternator, then over-rate the alternator quite a bit. Down side of this is if there is a big draw on the alt., it could stall the motor.
Kubota EL300A-R 4hp 12v Generator
Kubota B6100 HST Compact Tractor
Onan RDJA 8hp
1994 Chev S10 w/Isuzu C223
All are diesel.

MeanListerGreen

  • Sr. Member
  • ****
  • Posts: 305
    • View Profile
Re: HOUSE BOAT
« Reply #2 on: January 21, 2007, 03:43:06 PM »
Would a alternator off of heavy equiptment work?
MLG Gib Key Pullers

hotater

  • Hero Member
  • *****
  • Posts: 1557
    • View Profile
Re: HOUSE BOAT
« Reply #3 on: January 25, 2007, 03:03:05 PM »
There are a LOT of post on this subject in the generator section.  The semi-trucks use one that's highly reccommended and usually available on sale somewherer.
7200 hrs on 6-1/5Kw, FuKing Listeroid,
Currently running PS-Kit 6-1/5Kw...and some MPs and Chanfas and diesel snowplows and trucks and stuff.

biobill

  • Sr. Member
  • ****
  • Posts: 408
  • 'riods make good houseguests if fed right
    • View Profile
Re: HOUSE BOAT
« Reply #4 on: January 26, 2007, 12:28:36 AM »
White ox
  Is the 3.5 hp going to propel the houseboat? No watersking I guess ;D. Got any pics? this sounds right up my alley.
                                     Bill
Off grid since 1990
6/1 Metro DI living in basement, cogen
6/1 Metro IDI running barn & biodiesel processer
VW 1.6 diesels all over the place
Isuzu Boxtruck, Ford Backhoe, all running on biodiesel
Needs diesel lawnmower & chainsaw

okiezeke

  • Hero Member
  • *****
  • Posts: 642
    • View Profile
Re: HOUSE BOAT
« Reply #5 on: January 26, 2007, 01:08:43 AM »
I had a similar setup on my sailboat.  4hp kubota diesel engine belt driven to a 60 amp alternator. The alternor wouldnt carry my load, so I put a 150amp on.  Then the belt slipped all the time, so I went for bigger pullys/belt.  Then at full load the engine slowed down and stopped.  I know now that a little planning could have saved me years of trouble.

4hp will actually produce about 2kw

V-belts are called "fractional hp belts" for a good reason.

the system has to be built to handle PEAK draw, no matter what average need is

Your 3 1/2 hp engine will produce a total of about 1 3/4 kw.  900w is doable, but you need a 1800w alternator to avoid overheating the smaller alternator at peak power.  1800w divided by13v is about a 140amp alternator, and they dont usually come in 140a,. so you'll need a 150a.

 A 1/2" V-belt wont pull this much load.  You need to go to extra wide industrial V-belt, or better by far, a serpentine ribbed belt.  Of course, pullys must also be upgraded.

Now the system works good, except if you exceed your anticipated peak draw.  If you ask 2.0kw from the system the engine will overheat, stall, and/or find other ways to express unhappiness.

General rule for boating #33451:  You will ALWAYS need more power than you think you will.  Usually double or triple.

Probably wouldnt hurt to think in terms of what will produce 4kw.

In 5 years living aboard our Catalina 36 I know I've made every mistake possible in building marine power systems.  The above suggestions will cost more, but figure what a cheaper system that doesnt work is worth.

Zeke

Changfa type 25hp with 15kw ST head
Lovson 20-2 in blueprinting/rebuild
International TD-15 B  1962 dozer
Changfa 8 hp., 280 A battery charger