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Generac Power Systems Recreational Vehicle Generator 5413 User Manual

Page 7

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Section 1

GENERATOR FUNDAMENTALS

NOTE: AC output frequency at 3720 rpm will be

about 60 Hertz. The “No-Load” is set slightly high

to prevent excessive rpm, frequency and voltage

droop under heavy electrical loading.
Generator operation may be described briefly as fol-

lows:
1. Some “residual” magnetism is normally present in

the Rotor and is sufficient to induce approximately

7 to 12 volts AC Into the STATOR’s AC power

windings.

2. During startup, a Printed Circuit Board (PCB)

delivers battery voltage to the ROTOR, via the

brushes and slip rings.

a. The battery voltage is called “Field Boost”.
b. Flow of direct current through the ROTOR

increases the strength of the magnetic field

above that of “residual” magnetism alone.

3. “Residual” plus “Field Boost” magnetism induces

a voltage into the Stator excitation (DPE) and AC

Power windings.

4. Excitation winding unregulated AC output is deliv-

ered to an electronic voltage regulator, via an

excitation circuit breaker.

a. A “Reference” voltage has been preset into

the Voltage Regulator.

b. An “Actual” (“sensing”) voltage is delivered to

the Voltage Regulator via sensing leads from

the Stator AC power windings.

c. The Regulator “compares” the actual (sens-

ing) voltage to its pre-set reference voltage.

(1) If the actual (sensing) voltage is great-

er than the pre-set reference voltage, the

Regulator will decrease the regulated current

flow to the Rotor.

(2) If the actual (sensing) voltage is less than

the pre-set reference voltage, the Regulator

will increase the regulated current flow to the

Rotor.

(3) In the manner described, the Regulator

maintains an actual (sensing) voltage that is

equal to the pre-set reference voltage.

NOTE: The Voltage Regulator also changes the

Stator excitation windings alternating current (AC)

output to direct current (dC).
5. When an electrical load is connected across the

Stator power windings, the circuit is completed

and an electrical current will flow.

6. The Rotor’s magnetic field also induces a voltage

into the Stator battery charge windings.

Page 5

Figure 1-7. – Generator Operating Diagram