Piper SARATOGA PA-32-301 Maintenance Manual page 174

PIPER AIRCRAFT
PA-32-301/301T
MAINTENANCE MANUAL
D.C. GENERATION.
I ALTERNATOR SYSTEM - PRESTOLITE.
DESCRIPTION OF ALTERNATOR. (Refer to Figure 24-1.)
The principal components of the alternator are the brush holder assembly, the slip ring end head. the
rectifiers, the stator. the rotor and the drive end head.
1. The brush and holder assembly contains two brushes, two brush springs, a brush holder and
insulator. One brush is connected to a terminal stud and is insulated from ground. The other brush is
connected to ground through the brush holder. The brush and holder assembly can easily be removed for
inspection or brush replacement purposes.
2. The slip ring end head provides the mounting for the rectifiers and rectifier mounting plate. output
and auxiliary terminal studs. and the brush and holder assembly. The slip ring end head contains a roller
bearing and outer race assembly and a grease seal.
3. The rectifiers used in these units are rated at 150 peak inverse voltage (P.I.V.) minimum for transient
voltage protection. Three positive rectifiers are mounted in the rectifier mounting plate while the three
negative rectifiers are mounted in the slip ring end head. Each pair of rectifiers is connected to a stator lead with
high temperature solder. The stator leads are anchored to the rectifier mounting plate with epoxy cement for
vibration protection.
4. The stator contains a special lead which is connected to the center of the three phase windings. The
stator has been treated with a special epoxy varnish for high temperature resistance.
5. The rotor contains the slip ring end bearing inner race and spacer on the slip ring end of the shaft. The
rotor winding and winding leads have been specially treated with a high temperature epoxy cement to provide
vibration and temperature resistance characteristics. High temperature solder is used to secure the winding
leads to the slip rings.
6. The drive end head supports a sealed. prelubricated ball bearing in which the drive end of the rotor
shaft rotates.
I EFFECTIVITY: PRESTOLITE
24-31-01
Page 24-09
Revised: August 23, 1982
1H6