Owner`s manual
9 10
Starting And Stopping Procedures
Your Cummins Onan generator can be started and stopped from the integral
control panel on the generator, or from the optional remote control panel inside the
vehicle if your RV is so equipped. Your Operator’s Manual outlines the simple steps
for starting and stopping. Remember to:
• Before starting the generator, turn off air conditioners and large electrical loads.
• Before starting in cold weather, turn off all appliances for best long-term
performance.
• Prime by holding stop (all Quiet Diesels, Quiet Gas 3600-7000).
• To start - press and hold start at the control panel or at the set.
- Quiet Diesel: auto pre-heat fl ash, then crank/start
- Don’t over-crank with no start
• Before turning on appliances, let the generator warm up for a few minutes.
• Turn off air conditioners and large electrical loads and allow the generator to run
for 3-5 minutes before stopping, to allow the generator to cool down.
Breaking In Your New Generator
Your generator will perform better if you follow the break-in procedure
recommended in the Operator’s Manual. The break-in process typically involves
running the generator at about 50 percent load for two hours, then at about 75
percent load for two hours, then letting it cool down. You should change the engine
crankcase oil after the fi rst 20 hours of operation, and every 100 to 150 hours
thereafter. (See the Maintenance Chart on page 23-24 for specifi c intervals.)
Exercising Your Generator
It may seem surprising that “not” using a machine could cause performance
problems, but with RV generators that’s exactly the case. Regular “exercise” is
an important part of keeping your generator healthy. Lack of exercise can cause
moisture build-up and fuel system degradation that make it run poorly. In fact, in
as little as 30 days, the fuel in gasoline-powered generators can begin to gum
and varnish the fuel system. Fuel varnishing results in hard starting and surging. (A
surging generator never settles at a stable operating speed.)
To prevent such problems, it is recommended to run gasoline generators at a
minimum of 50 percent capacity (2000-watts, or one air conditioner for a 4000-watt
set) for two hours once every four weeks. This is necessary to help keep moving
parts lubricated, expel moisture and control fuel varnishing in the carburetor. A long
two-hour exercise period is preferable to several short periods. While traveling, this
can be accomplished by running the air conditioning. If you own a diesel generator,
regular exercising can help reduce internal condensation and helps keep seals
lubricated.
Operating Motor Driven Appliances
When using an appliance with a motor, turn it on and let it reach normal running
speed before starting other appliances. Air conditioners, like all electric motors,
can draw up to three times more power during the fi rst few seconds of start up
than during normal operation. While this is common for all electric motors, it is
especially true for air conditioners if the compressor tries to start against built-up
high pressure in its refrigeration system.
Air Conditioner “Short-Cycling”
When an air conditioner runs, the compressor builds refrigerant pressure. When the
compressor is then shut off, either manually or by satisfying thermostat demand,
it must stay off for some period of time, usually 3-4 minutes, to allow pressure in
the system to equalize before safely restarted. Trying to restart the air conditioner
compressor before pressure equalizes is known as “short-cycling”.
A “short-cycled” air conditioner could 1) trip the air conditioner circuit breaker;
2) shut down the generator due to overload; or 3) trip the air conditioner due to
thermal overload. The air conditioner thermal overload will reset itself after the
compressor cools. Typically, you cannot manually reset.
Some, but not all, RV air conditioner thermostats have built-in time delays to
prevent short-cycling. Short-cycling occurs in some RVs when the thermostat is
mounted so that cold air blows directly on it. If this happens, the thermostat shuts
the compressor off before the cabin has cooled, but quickly warms back up and
signals the compressor to restart before refrigerant pressure equalizes. In this case,
direct the fl ow of air from the air conditioner away from the thermostat or relocate
the thermostat. You can prevent air conditioner short-cycling by always ensuring the
air conditioner rests for 3-4 minutes after the compressor shuts off before trying to
restart it.
Effects Of High Altitude And Extreme
Temperatures
If you travel at high altitudes or in extreme temperatures, your generator can lose
power. In such lower-density air conditions, you can’t operate as many electrical
devices as you could under normal operating conditions.
Power decreases 3.5% for each 1,000 feet above an altitude of 500 feet. For
example, to operate at 4,500 feet (4,000 feet above rated generator altitude)
multiply 3.5% x 4 (4,000 ft) = 14% power loss. Then multiply .14 x your
generator’s power rating: 4,000 watts x .14 = a loss of 560 watts at that altitude.
Power decreases in extreme temperatures by 1% for each 10° F (5.5° C)
above 85° F (29.4°C).
NOTE:
The carburetor on a non-EFI gasoline generator may require adjustment at high altitudes.
(See your Operator’s Manual or your Cummins Onan Authorized RV Service and Parts Dealer.)