Generac Power Systems 004701-0 用户手册

下载
页码 56
 
 
9
Section 2 – Operation
Recreational Vehicle Generator
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 284º F (140º C), initiating an engine 
shutdown.
Figure 2.2 – Low Oil Pressure and 
High Temperature Switches
High Temperature Switch
Low Oil Pressure
Switch
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 components are part of 
a “field boost” circuit (Figure 2.3). During engine 
cranking only, a positive DC (battery) voltage is 
delivered through the diode, resistor, brushes and 
slip rings, to 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
‹
‹
 2.8.4  OVERVOLTAGE PROTECTION
A solid-state voltage regulator (Figure 2.4) controls 
the generator’s AC output voltage. This regulator sup-
plies an excitation current to the rotor. By regulating 
the rotor’s excitation current, the strength of its mag-
netic field is regulated and, in turn, the voltage deliv-
ered to connected electrical loads is controlled. When 
the AC frequency is 60 Hertz, voltage is regulated at 
120 volts (voltage-to-frequency ratio is 2-to-1).
Figure 2.4 – Solid State Voltage Regulator
The voltage regulator also incorporates a “voltage 
surge protection circuit.” This circuit prevents trou-
blesome surges in the generator AC output voltage. 
Voltage surge is a common cause of damage to elec-
tronic equipment.
2.9   ADDITIONAL INFORMATION
2.9.1  25-HOUR BREAK-IN PERIOD
The first 25 hours of operation is the break-in period 
for the generator. Properly breaking in the genera-
tor is essential to minimize fuel consumption and 
provide maximum engine performance. During this 
25-hour break-in period, follow this procedure:
•  Run the unit at varying electrical loads to help seat 
the engine piston rings properly.
• Check the engine oil level frequently. Add oil if 
needed. It is normal for the generator engine to 
consume more oil than is normal until the piston 
rings have properly seated.
• For the 75-hour operation following the break-in 
period, avoid light electrical loads. Load the gen-
erator at 50 percent (or more) of its rated watt-
age capacity. Repeated light loads during these 75 
hours can cause improper seating of engine piston 
rings, resulting in blowby and high oil consump-
tion.
•  After operating the unit for 25 hours, complete the 
tasks recommended under "25-Hour Check-up".
‹
‹