10
Section 2 – Operation
Recreational Vehicle Generators
2.7
APPLYING LOADS TO
GENERATOR
When applying electrical loads to the generator, observe these
guidelines:
Before applying electrical loads, let the generator stabilize and
•
warm up for a minute or two.
DO NOT overload the generator.
•
2.7.1 LETTING THE ENGINE STABILIZE
The generator supplies correct rated voltage only at the proper
governed speed. Some electrical appliances may be extremely
sensitive to voltage. Incorrect voltages can damage such appli-
ances.
If electrical loads are applied at reduced operating speeds, such
loads imposed on the engine when sufficient power is not available
may shorten engine life. Never turn ON electrical loads until after
the generator engine has started and stabilized at no-load.
2.7.2 DO NOT OVERLOAD THE GENERATOR
Read the rated wattage/amperage capacity of the generator on the
generator data label (See the "Generator Identification" section.).
Applying electrical loads in excess of the unit’s rated capacity will
cause the engine/generator to automatically shut down.
To avoid overloading, add up the wattage of all connected electrical
lighting, appliance, tool and motor loads. This total should not be
greater than the generator’s rated wattage capacity.
Most lighting, appliance, tool and motor loads indicate their
•
required watts on their nameplate or data plate. For light bulbs,
simply note the wattage rating of the bulb.
If a load does not show its rated wattage, multiply that load’s
•
rated VOLTS times AMPS to obtain WATTS.
Induction type motors (such as those that run the vehicle’s
•
furnace fan, refrigerator, air conditioner, etc.) need about 2-1/2
times more watts of power for starting than for running (for a
few seconds during motor starting). Be sure to allow for this
when connecting electrical loads to the generator. First, figure
the watts needed to start electric motors in the system. To that
figure, add the running wattages of other items that will be oper-
ated by the generator.
Do not apply heavy electrical loads for the first two or three
•
hours of operation.
2.8 PROTECTION
SYSTEMS
2.8.1 LOW OIL PRESSURE SWITCH
This switch (Figure 2.2) has normally closed (N.C.) contacts that
are held open by engine oil pressure during cranking and operat-
ing. Should oil pressure drop below a preset level, switch contacts
close, and the engine automatically shuts down. The unit should
not be restarted until oil is added.
2.8.2 HIGH TEMPERATURE SWITCH
This switch (Figure 2.2), which has normally open (N.O.) contacts,
is mounted near the oil filter. The contacts close if the temperature
should exceed approximately 270º F (132º C) for gasoline mod-
els.
Figure 2.2 – Low Oil Pressure and
High Temperature Switches
2.8.3 FIELD
BOOST
The Controller Circuit Board houses a field boost diode and resistor
that are not part of the automatic choke circuit. These two compo-
nents are part of a “field boost” circuit (Figure 2.3). During engine
cranking only, a positive DC (battery) voltage is delivered through
a diode, resistor, brushes, slip rings, and the generator rotor.
Application of this voltage to the rotor “flashes the field” whenever
it is started. Flashing of the field each time the generator starts
makes sure that a sufficiently strong magnetic field is available to
produce “pickup” voltage in the stator windings.
Figure 2.3 – Field Boost Circuit
Summary of Contents for RV 45 SERIES
Page 18: ...16 Section 4 Notes Recreational Vehicle Generators ...
Page 38: ...36 Section 5 Notes ...
Page 39: ...37 Section 5 Notes ...
