Piper CHEROKEE WARRIOR PA-28-151 1995 Maintenance Manual page 386

PIPER CHEROKEE WARRIOR SERV I C E M A N U A L
11-5. P R E S TOLITE AND ELECTROSYSTEMS ALTERNATOR AND COMPONENTS
11-6. GENERAL
The PA-28-151, Warrior and PA-28-161, Warrior II were equipped with either a 14 Vdc, 60 amp
Prestolite or Chrysler alternator. The later version of the PA-28 161, Warrior II were equipped 14 Vdc, 60 amp
Electrosystems (formally Prestolite) alternators. The PA-28-161, Warrior III is equipped with an
Electrosystems 28 Vdc, 70 amp alternator.
11 - 7 DESCRIPTION OF PRESTOLITE AND ELECTROSYSTEMS ALT E R N ATO R S (See Figure 11-1)
The principle components of both 14 Vdc, 60 amp, and either the 14 Vdc, 60 amp or 28 Vdc, 70 amp
Prestolite and Electrosystems alternators are basically the same. Thus, the following applies to both of these
alternators.
The principle components of the alternator are the brush holder assembly (1), the slip ring end head
(2), the rectifiers (3), the stator (4), the rotor (5), and the drive end head (6).
a. The brush and holder assembly contains two brushes, two brush springs, a brush holder and
insulator. Each brush is connected to a separate terminal stud and is insulated from ground. The brush and
holder assembly can easily be removed for inspection or brush replacement purposes.
b. 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.
c. The rectifiers used in these units are rated at 150 peak inverse voltage (PIV) 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.
d. The stator contains a special lead which is connected to the center of the three phase windings,
and is used to activate low voltage warning systems or relays. The stator has been treated with a special epoxy
varnish for high temperature resistance.
e. 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.
f. The drive end head supports a sealed, pre-lubricated ball bearing in which the drive end of the
rotor shaft rotates.
11-8 CHECKING PRESTOLITE AND ELECTROSYSTEMS ALTERNATOR SYSTEM
With the engine operating, and all electrical equipment, except master switch, OFF, the ammeter will
read amount of charging current demanded by battery. The amount will vary, depending on percentage of battery
c h a rge. As the battery is c h a rged, the current displayed on the ammeter will reduce to approximately two
amperes. Current reading on the ammeter will show if the alternator system is operating normally.
Revised: February 28, 1995
2E3
Island Enterprises
ELECTRICAL SYSTEM