Circuit Breakers; Operation - DeWalt DXGN4500 Manual

Section 1 Capacitive Discharge (Brushless)

Circuit Breakers

See Figure 1-3. Each individual circuit on the generator
is protected by a circuit breaker to prevent overload.
MLB = MAIN LINE
CIRCUIT BREAKER
120 VAC
STATOR
POWER
WINDING
ENGINE -
DIRECT
DRIVE
Figure 1-3. Generator Operating Diagram

Operation

Startup
When the engine is
magnetism from the rotor induces a voltage into (a) the
stator AC power windings, and (b) the stator excitation
windings. In an "On-speed" (engine cranking) condition,
residual/permanent magnetism is capable of creating
approximately one to three Volts AC.
2
TO LOAD
MLB
240 VAC
120 VAC
STATOR
POWER
WINDING
MAGNETIC
FIELD
ROTOR
MAGNETIC
FIELD
STATOR
EXCITATION
WINDING
CAPACITOR
started, residual/permanent
On-Speed Operation
As the engine accelerates, the voltage that is induced
into the stator windings increases rapidly, due to the
increasing speed at which the rotor operates.
Field Excitation:
An AC voltage is induced into the stator excitation
windings. The excitation winding circuit is completed to
the capacitor where the capacitor is charged until the AC
voltage peaks and then discharges as the AC voltage
starts to decay. The charging and discharging causes a
voltage to be induced back into the rotor which will
produce voltage. The greater the current flow through the
rotor windings, the more concentrated the lines of flux
around the rotor become. The more concentrated the
lines of flux around the rotor that cut across the stationary
stator windings, the greater the voltage that is induced
into the stator windings. Initially, the AC power winding
voltage is low, but as the capacitor is charged and
discharged this relationship between the rotor and the
capacitor is what will regulate voltage at a desired level.
AC Power Winding Output
A maintained voltage is induced into the stator AC power
windings. When electrical loads are connected across
the AC power windings to complete the circuit, current
can flow in the circuit.
003817
NOTE: The voltage of a brushless capacitive discharge
generator will start low and increase as load is applied.
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