Generac Power Systems 00847-1, Operating & Installation Manual

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Generac ® Power Systems, Inc. 9
Figure 3.3 — 12 Position Terminal Block
3.3 ELECTRICAL PANEL
The Electrical Panel, mounted at one end of the
enclosure contains all the electrical components for
proper unit operation (see Figure 3.4).
3.4 ELECTRICAL OPERATION
The engine runs at a speed of 2700 RPM and drives
the alternator at 3600 rpm, producing an AC 6 phase
voltage. This voltage is taken directly from the stator
windings and into two independent 3-phase bridge
rectifiers. The DC output from the rectifier is then fed
into an inductive-capacitive filter assembly designed
to reduce the AC ripple content of the DC output. The
output of the filter is then fed directly to the genera-
tor output terminals.
12 V DC fans assist in cooling both the rectifier and
filter during generator operation. During any inspec-
tion or service of the generator, the operation of both
fans should be checked and replaced if faulty.
The following section describes in some detail most
of the components the user may interface with.
3.4.1 VOLTAGE REGULATOR
A solid state voltage regulator (Figure 3.5). controls
the generator output by supplying an excitation cur-
rent to the rotor. By regulating the rotors excitation
current, the strength of its magnetic field is regulated.
This, in turn, controls the output voltage. To regulate
the field current to the rotor, the voltage regulator
must be connected to the customer DC Bus. This pro-
vides sensing voltage to the regulator. Figure 3.6
shows a simple schematic for the voltage regulator.
Figure 3.5 — Voltage Regulator
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Section 3 — Operation
Generac APS 6.0 DC Auxiliary Power System
Figure 3.4 — Electrical Panel
Control PCB
12 VDC Fan
Current Transformer
Smoothing
Capacitor
3-Phase Bridge
Rectifier
Ground Terminal Hour Meter
Voltage
Regulator