Piper SENECA II - Alternator Nomenclature; Alternator Service Test Specifications

PIPER SENECA II SERVICE MANUAL
11-15. ALTERNATOR SERVICE TEST SPECIFICATIONS. Prestolite specifications for the 14-volt
alternators installed as standard equipment on PA-34-200T airplanes are as follows:
TABLE XI-II. ALTERNATOR SPECIFICATIONS
Alternator Model ALY 9402
Voltage
12 volts
Rated Output
65 amperes
Ground Polarity
Negative
Rotation
Bi-Directional
Rotor:
Current Draw (77 ° F)
3.2A nominal 4.0 max
Resistance (77° F)
4 ohm nominal
3 ohm min.
Output Test (77° F)
I
Volts
14.0 ± .2
Amperes Output
65
Field Amperes
3.2A nominal
Alternator RPM
5167
11-16. ALTERNATOR NOMENCLATURE.
a. Bearings: These units have a sealed ball bearing at the drive end and a two-piece roller bearing at
the slip ring end. The inner race is pressed onto the rotor shaft and the rest of the bearing is in the slip ring
end head. When the unit is assembled, the inner race aligns with the bearing. When the bearing is replaced,
the new inner race must be installed on the rotor shaft.
b. Lubrication: The slip ring end bearing should be lubricated whenever the alternator is
disassembled. The bearing should be thoroughly cleaned and repacked with Shell Alvania No. 2 or an
equivalent bearing lubricant. The cavity behind the bearing should be packed one-third to one-half full with
the same lubricant.
c. Brushes: These units have a separate brush holder assembly that is installed after the alternator
has been assembled. The brush holder has a small hole that intersects the brush cavities. Use a pin or a piece
of wire to hold the brushes in the holder during assembly. Remove the pin after the brush holder retaining
screws have been tightened. Make a continuity check to be sure the brushes are seated against the slip rings.
Reissued: 10/11/79
2G8
ELECTRICAL SYSTEM