Originally Posted by Honey Ryder
Does anybody have a generator
which runs off their main large engine
that works sufficiently well so that electronic equipment
can be powered by AC?
set-up is a 130hp normally aspirated diesel
to drive the prop shaft, and a separate small diesel
to produce AC.
Is it possible to hook up and run a generator head
off the 130hp and get rid of the small engined generator? And does it make sense?
I've read that generators need to be run at a constant 3600rpm to maintain voltage and amperage...which means that there is a problem if the rpm
on the large engine
is not held constant...is there a solution?
Replying to the OP's ?:
I have belt driven a 8KW 3600RPM generator off the "front" end of my Perkins
4.236 for 26 years. The 4.236 was designed as an industrial type engine that could deliver the same load off either end, so I built a frame to hold the generator, (my boat has a Vee drive, so the engine sets backward, i.e. the gear
is attached to the aft end of the engine, which is pointed toward the bow of my boat). I had had the boat several years so I knew my most efficient motoring speed/RPM's was 6.2 knots at 1,550 RPM
= 1.1 gallon per hour. So, I attached pulleys twin belt of the proper ratio to drive the generator at 3,600 RPM's when I was motoring at 1,550 RPM's . I set exact RPM's using a AC voltmeter @ 117 volts and a hertzmeter at 60 hz.
Theoretically, in smooth seas, clean boat bottom, my Cal 46
only requires 18HP to maintain 6.2 knots, so the extra load on the engine is negligable. Whenever we are motoring or motor
sailing, we have the generator working and usually running our 120 volt AC, 20 GPH RO watermaker
. When we reached our anchorage, we had a full 200 gallons of pure water
and no indication of additional fuel
usage. I have a 50 gallon day tank in the engine room with a marked sight gauge, so I closely monitor fuel consumption
. I have an additional 350 gallons in amidships tanks
. Yes, I am a motorsailer
since there are places where the wind
does not blow.
This simple system has worked well for me, 26 years, 3,600 engine hours, nine years full time cruising. It was great!
Anyone desiring more technical info, PM.
Keep It Simple