Checking Alternator System - Piper SENECA II Service Manual

PIPER SENECA II SERVICE MANUAL
d. 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.
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, prelubricated ball bearing in which the drive end of the
rotor shaft rotates, and a blast tube connection for ventilation.
11-7. CHECKING ALTERNATOR SYSTEM. Two ammeters are used which enable an independent
output check of eac~ alternator, as well as the electrical output-input of the battery. Should either alternator
show no output on its ammeter, check the appropriate circuit breakers. If a further check of the ammeters
show no output from both alternators, check the alternator system. (Refer to Combined Schematic Figure
11-23.)
a. Ascertain that the ammeters are operating properly.
b. Disconnect the battery lead(+) at the alternator.
c. Disconnect field leads at the alternator.
d. Ascertain that all electrical units are off and battery is full charged.
e. Turn on the master switch.
f. To check the alternator output circuit, connect a voltmeter or 12-volt test light to the battery
lead and to ground. If a reading of approximately 12-volts registers on the voltmeter or the test lights, the
battery circuit is operational.
g. Should there be no indication of voltage, trace back through the output circuit until voltage is
indicated. A component that allows no voltage to pass through it should be replaced.
Revised: 3/16/81
ELECTRICAL SYSTEM
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