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Section 3
DESCRIPTION & COMPONENTS
Figure 3-2. – The 2-Pole Rotor Assembly
STATOR ASSEMBLY
The stator can houses and retains (a) dual AC power
windings, (b) an excitation winding, and (c) two bat-
tery charge windings. A total of thirteen (13) stator
leads are brought out of the stator can as shown in
Figure 3-3.
The stator can is sandwiched between an engine
adapter and a rear bearing carrier. It is retained in that
position by four stator studs.
11
44
22
77A
55
77
6
2
66
66A
55A
44S
11S
Figure 3-3. – Stator Assembly Leads
BRUSH HOLDER AND BRUSHES
The brush holder is retained to the rear bearing car-
rier by means of two Taptite screws. A positive (+) and
a negative (-) brush are retained in the brush holder,
with the positive (+) brush riding on the slip ring near-
est the rotor bearing.
Wire 4 connects to the positive (+) brush and Wire 0
to the negative (-) brush. Wire 0 connects to frame
ground. Rectified and regulated excitation current, as
well as current from a field boost circuit, are delivered
to the rotor windings via Wire 4, and the positive (+)
brush and slip ring. The excitation and field boost cur-
rent passes through the windings and to frame ground
via the negative (-) slip ring and brush, and Wire 0.
This current flow creates a magnetic field around the
rotor having a flux concentration that is proportional to
the amount of current flow.
4
0
Figure 3-4. – Brush Holder and Brushes
OTHER AC GENERATOR COMPONENTS
Some AC generator components are housed in the
generator control panel enclosure. These are (a) an
Excitation Circuit Breaker, (b) a Voltage Regulator,
and (c) a main line circuit breaker.
EXCITATION CIRCUIT BREAKER:
The Excitation Circuit Breaker (CB2) is housed in the
generator control panel enclosure and electrically
connected in series with the excitation (DPE) wind-
ing output to the Voltage Regulator. The breaker is
self-resetting, i.e.; its contacts will close again when
excitation current drops to a safe value.
If the circuit breaker has failed open, excitation current
flow to the Voltage Regulator and, subsequently, to
the rotor windings will be lost. Without excitation cur-
rent flow, AC voltage induced into the stator AC power
windings will drop to a value that is commensurate
with the rotor residual magnetism (see Figure 3-5).
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