[Vwdiesel] Re: genset applications

[Area31 Research Facility]

Shawn,

The great reputation that the VW diesel has and the fact of it's smalish
size (for good fuel economy) is exactly why I decided to go with this engine
in my generator.  I agree with you that a stationary engine, well cared for
ought to outlast one on the road.  I wouldn't be surprised if it lasted
twice as many revolutions.  The facts are that a slower running engine will
outlast one spinning faster as long as you aren't lugging it.  It is for
this reason that I decided to go with 1800 RPM.  It is a compromise speed.
This is at the bottom of the useable power band for the VW engine, but will
give it in my expectations, a very long service life in a stationary
application.  Going direct drive gets you the maximum possible efficiency in
your drive coupling to the alternator.  Unfortunately for 60 Hz power you
are stuck with certain widely spaced RPM settings to make mains equivalent
electricity depending on the number of poles in the alternator.  Two pole
alternators require to be spun at 3600 RPM.  Four poles, 1800, six poles
1200, eight poles 900 and sixteen poles get to spin at 450 RPM.  Those are
usually only seen in really big diesel generators.

I wanted a plant that could be run 24/7 as a prime power source.  The only
way you can get decent service life is to go slow.  That is why I'm looking
at even running at 1200-1300 RPM in a low power battery charging mode.  I
want to get at least three years out of a plant before I have to do a major
engine rebuild, more if possible.

I stand by my statement.  If you talk to anyone in the commercial generator
business who deals in stationary built-in plants for industry, farms,
greenhouses, hospitals, telecom, etc.,  what I said is true, 3600 RPM is
like a swear word to them.  I am not talking the same league as portable
generators used by contractors and homeowners during occasional power
outages, not do I have any interest in owning another of those after my last
one committed suicide last December.

Rob

----- Original Message -----
From: "Shawn Wright" <swright at zuiko.sls.bc.ca>
To: <vwdiesel at vwfans.com>
Sent: Thursday, May 19, 2005 11:36 PM
Subject: Re: [Vwdiesel] Re: genset applications


> On 19 May 2005 at 19:18, Area31 Research Facility <stephensrw at stn.net>
wrote:
>
> > BTW, 3600 RPM is like a swear word to serious genset people.  3600 RPM
is good
> > for the folks that sell those crappy consumer generators, not good for
the
> > uneducated people that buy them and have to throw them away after 30
hours use.
>
> Rob,
>
> I don't know much about gensets, but I do know that the VW diesel (and gas
for that
> matter) is just fine at 3600rpm and a long service life. Consider that
those revs are
> typical for a vehicle application at freeway speeds, and many of these
vehicles
> routinely surpass 500k kms without engine problems. I've had 4 of them in
my
> immediate family that have passed this mark on the original engine, 2 gas,
2 diesel,
> and probably another 6-8 that have gone over 300k. Figure on an average
lifetime
> speed of 50km/h (I don't know if this is realistic?), this equals 10,000
hrs. I would
> think the relatively steady state duty of a genset would be favourable for
longevity,
> compared with a vehicle, even at 3600 rpm.
>
> Shawn Wright
> http://zuiko.sls.bc.ca/~swright
> '85 Jetta D
> '88 Westy 2.1L, soon to be 1.6TD 5 speed
>  (see progress at http://members.shaw.ca/vwdiesels)
> '82 Diesel Westy
>
>
> _______________________________________________
> Vwdiesel mailing list
> Vwdiesel at vwfans.com
> http://www.audifans.com/mailman/listinfo/vwdiesel
>