DC current flows from the battery to brushes and sl
on the rotor. See Figure 6-28.
ip rings
6-5. BRUSHES
6-5.1 General. The brushes transfer current from the volt-
age regulator to slip rings. The brushes carry a very low cur-
rent (approximately 2 Amps) and should last the life of the
generator set. Abrasive dust on the slip rings could, how-
ever, shorten the life of the brushes. Excessive arcing at the
brushes could damage the voltage regulator. Arcing could
be caused by weak springs, damaged slip rings, sticking
brushes, loose holder, or poor brush alignment.
6-5.2. Maintenance.
1. Remove the end bracket panel to gain access to the
brushes.
2. The brushes must be free to move within the holder and
held in proper contact by the springs. When properly
positioned, spring pressure on the brush surface will
cause the brush to wear evenly. Figure 6-29 shows normal
brush wear.
3. Replace the brushes if worn excessively or unevenly.
4. Replace the springs if damaged or discolored.
5. Be sure to use original or identical l/2 inch (12.7mm)
screws when reinstalling the brush holder. Longer screws
will break the holder when tightened.
6. To install the brushes and holder insert a wire as shown
in Figure 6-30, to hold the brushes in. Position the brushes
on the slip rings and install the two screws. Remove the
wire.
CAUTION
If the retainer wire is not removed, the voltage
regulator will be damaged when the generator
is started.
Figure 6-29. Brushes
WIRE
Figure 6-30. Brush Holder
STARTER
GENERATOR
ROTOR
/
BRUSHES &
SLIP RINGS
4CR
GENERATOR
REGULATOR
12 VOLT
BATTERY
Figure 6-28. Buildup Circuit
6-8