Low voltage out of Genset

[one_dusty_hoot]

John, excellent point, "assume" can get one
into a lot of trouble. And yes, I was assuming
that both leg voltages were nearly equal.

But...Suppose leg 1 had a normal voltage reading
of 120 VAC and leg 2 read the 95 VAC. Then it
is possible because of heavy load on leg 2, maybe
a hi-amp charge rate, or, dragging AC motor, the
additional current requirement has decreased the
voltage to 95 VAC and the genset is fine.

The only assumption that can safely be made is
that it did operate properly at one time.

Alan, give us some more infomation on the voltage
using a multimeter. Could be a defective gage as
well?

Bob Janes '87FC35 Greenville, SC


--- In WanderlodgeForum@yahoogroups.com, John Suter
wrote:
>
> Alan, we (the group) are assuming the low voltage you
> report is equally low for both legs. If not, advise
> the as we might have to modify the advice.
>
> John Suter
>
>
> --- one_dusty_hoot wrote:
>
> > Alan, the genset puts out 2 cycles per revolution,it
> > should run at 1800 rpm, govenor controlled. This
> > would
> > output 1800 X 2=60 cycles per second. As load is
> > increased, the speed decreases, then more fuel is
> > given by the govenor to maintain speed.
> >
> > Look at the governor next on the motor, there is an
> > arm that goes against a stop when the generator is
> > started. There at the stop point is the speed
> > adjustment.
> >
> > Before you start adjusting the stop you need to know
> > what speed your motor is turning. You can buy a
> > vibration tachometer at small motor repair shops.
> > You can move the wand in and out by turning the
> > knob. When the harmonic frequency is reached, the
> > extended arm will begin vibrating rapidly. Mayve
> > $20?
> >
> > Do not attempt to adjust speed without something as
> > a reference.
> >
> > Your problem may be that the motor is running sour,
> > could be the air filter is clogged, and possibly not
> > enough diesel by a dirty filter?
> >
> > Bob Janes 87FC35 Greenville, SC
> >
> >
> >
> >
> > --- In WanderlodgeForum@yahoogroups.com, Curt
> > Sprenger
> > wrote:
> > >
> > > I'm not an expert but found this on the Internet.
> > For an
> > oscillating or
> > > varying current, frequency is the number of
> > complete cycles per
> > second
> > > in alternating current direction. The standard
> > unit of frequency is
> > the
> > > hertz, abbreviated Hz. If a current completes one
> > cycle per second,
> > then
> > > the frequency is 1 Hz; 60 cycles per second equals
> > 60 Hz (the
> > standard
> > > alternating-current utility frequency in the
> > United States).
> > >
> > > I recall the Onan guy adjusting rpms on our
> > previous gen. set to
> > get the
> > > frequency to 60 and to increase voltage.
> > >
> > > Sounds to me you are on the right track. If you
> > can, turn up the
> > rpms
> > > and watch for voltage increase. Good luck. Please
> > keep us posted.
> > >
> > > Curt Sprenger 1987 PT38, Anaheim Hills, Calif.
> > >
> > >
> > >
> > > Alan wrote:
> > >
> > > > My 87FC35 has a 8.0 kW genset. I am getting low
> > voltage out of it
> > > > (around 95 volts). On my last onan genset (77
> > GMC - carbed gas),
> > > > this was a common problem and was simply
> > corrected by increasing
> > > > RPMs. (If this is the fix, how do I adjust idle
> > speed? This fuel
> > > > injection isn't as intuitive for me as I've been
> > a carburetor
> > guy.)
> > > >
> > > > I found an installation manual for the genset
> > and it says to
> > adjust
> > > > some "taps" on a transformer regulator. It also
> > says "output
> > > > frequency is determined by engine speed and
> > normally does not
> > > > require adjustment." I'm not exactly sure what
> > it means by "output
> > > > frequency". Is that voltage??
> > > >
> > > > Is this problem more complicated than adjusting
> > the RPMs? Maybe I
> > > > don't have one of the Onan manuals..?? I have a
> > parts manual and
> > an
> > > > installation manual.
> > > >
> > > > I have searched the forums and did not find a
> > post that seemed to
> > > > address my situation. Let me know if I missed
> > it.
> > > >
> > > > Thanks in advance,
> > > > Alan Johnson
> > > > 87FC35
> > > >
> > > >
> > >
> >
> >
> >
> >
> >
>
>
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