Owner`s manual
17 18
Q: Once the generator is started, should it continue to run for a
certain length of time?
A: Ideally
, Cummins Onan generators should run for a minimum of 30 minutes to
give them a chance to warm up. Once warmed up, running your generator for
fi ve-minute intervals should be fi ne. But remember to turn on some appliances
so the generator works while it’s running. Running it for more than 30 minutes
at no load only burns fuel unnecessarily and adds costly maintenance.
Q: How are “will-fi t” generator replacement parts different from
Green Label Parts
™
?
A: Cummins Onan genuine Gr
een Label Parts
™
are tested and designed
specifi cally for RV applications. Will-fi t parts and gaskets can be the correct
shape, but because of inadequate design, the wrong material, or poor quality,
they could cause premature failure, leakage or performance problems. Use
of some non-Cummins Onan replacement engine parts may affect the unit’s
emissions certifi cation, and damage caused by use of oil and air fi lters other
than Green Label Parts is not covered under your generator warranty.
Q: How often should I perform maintenance on my generator? Will
doing it myself affect my warranty?
A: The Operator’
s Manual that accompanies each generator outlines proper
maintenance procedures and intervals. If you follow the procedures correctly,
warranty coverage remains intact. However, proper maintenance will obviously
affect warranty coverage. For more information, see the Maintenance Intervals
charts on page 23.
Q: How frequently should I change oil if I won’t be using the
generator for several months?
A: T
ypically just like a car, change oil for seasonal temperature changes. For long
storage, see your Operator’s Manual for extended out-of-service protection.
Q: Should I use straight 30-weight oil or is the multi-viscosity oil I
use in my vehicle okay?
A: For best generator performance, we r
ecommend you use Onamax,
™
the Green
Label Parts oil specifi cally formulated for RV generators. However, you can use
the same oil you use in your vehicle engine provided it meets or exceeds SG/
CE API specifi cations. To get you off to a good start, all new Cummins Onan
generators are factory prepared with Onamax 15W-40 oil.
Q: Will high-octane gasoline reduce the amount of fuel varnish?
A: No, because var
nish is a form of fuel degradation that is not a function of
octane level. Rather, it is a function of fuel quality, age and additive treatment.
High-octane fuel without stabilizer additive will oxidize or varnish at a faster rate
than fuel treated with a fuel stabilizer.
Q: When I’m checking my oil, does the dipstick need to be screwed
in all the way?
A: In or
der to get the correct oil level reading, the dipstick must be screwed in
completely on all models with a screw-type dipstick, except for the RV QG
2800/2500 & RV QG 2800/2500 RM models; it sits on top of the fi ll tube.
Make sure the vehicle is level when checking oil level.
Q: Do diesel generators need exercising like gasoline generators?
A: Y
es, it helps lubricate the seals and engine components and keeps carbon
from building up. Regular exercise also heats up the generator windings and
removes or expels excess moisture. In sets equipped with brushes, exercising
helps prevent corrosion build up on the slip rings.
Q: How do I keep mice/rodents out of my generator during storage?
A: Use r
odent prevention techniques around the generator/compartment just as
you would with any other area of your RV.
Q: Can I use the RV QG 4000 RM, RV QG 4000 or
Emerald 4000 generator to run two air conditioners?
A: No.
Q: Will the starter motor continue to be engaged if the start button
is held too long?
A: All Cummins Onan generators ar
e equipped with a start disconnect feature
which will not allow the starter to crank once the generator is producing
electrical output.
Q: Why don’t I have as much power as I think I should?
A: Battery chargers run as “invisible” loads, and can draw as much power
as two air conditioners, depending on size. This can continue for several
hours, depending on battery charger and battery bank size. (See the Battery
Management section on page 12 for mor
e information.)
LP Generators
Q: Should I get an LP or a diesel generator for my diesel
motorhome? What are the differences?
A: Each fuel option has its own advantages. LP generators generally have a lower
initial cost than diesel units. Plus, they’r
e smaller and lighter weight, allowing
for more fl exibility in the fl oor plan of large RVs. LP generators also have less
exhaust fume smell. Diesel generators have a much longer engine life. They
consume less fuel, and diesel fuel usually costs less than LP, which brings
additional savings. A diesel generator gives you a common fuel system, and the
convenience of operating your generator from the vehicle’s main fuel supply.
The generator best for you depends on how you use it and your own personal
preferences.
Q: How is LP fuel supplied to my generator?
A: LP fuel is stor
ed in the fuel tank in liquid form with some vapor at the top of
the tank at relatively high pressure. The pressure in the tank is determined by
the ambient (outdoor) temperature. The higher the temperature the higher the
pressure. Ambient heat vaporizes fuel until the pressure won’t allow any more
liquid to vaporize. The tank pressure will be about 200 psi at 110°F, 70 psi at
40°F, and 0 psi at -40°F (40°C).
In order for the fuel to be burned at a controlled rate in the generator (or
any other appliance) it must be converted to a vapor form and supplied at
a controlled pressure.
LP fuel systems for many Cummins Onan generators are available in two
forms, vapor withdrawal and liquid withdrawal.