Preparation For Testing - Piper SENECA II Service Manual

PIPER SENECA II SERVICE MANUAL
k. The balancing regulator system as described provides for automatic load balancing of parallel
operated alternators having independent field excitation circuits. The pilot can while in flight remove either
alternator system completely from the aircraft system and maintain operation of the other system.
11-21. PREPARATION FOR TESTING. (Regulators may be tested using the aircraft's alternator or an
alternator test stand.)
CAUTION
Do not interchange regulator leads. This will destroy regulator and
void warranty.
a. The aircraft technician or other electrical system's specialist must disconnect the battery ground
cable at the battery before connecting or disconnecting a test ammeter or other test equipment or before
making wiring changes in the electrical system.
b. Voltmeters with test probes or clips are not recommended. Fully insulated bolted terminal
connections are best and these should be attached when all power is removed as described above.
c. When installing a battery in an aircraft, be sure that the battery negative terminal is in a position
so that this terminal can be connected to the battery ground cable for negative ground systems.
d. The regulator under test is to be mounted on a grounded metallic surface using three No. 8
screws pulled up tight. For extended test periods the heat transfer from regulator to the mounting surface is
significant.
e. A ground wire between the regulator "GND" terminal and the aircraft or test stand structure is
essential for proper operation. The alternator frame must also be solidly bonded to the system ground.
f. The alternator does not need to be polarized; therefore, never connect ground even momentarily
to either the regulator field terminal or to the alternator field terminals. Do not interchange leads to
regulator as this will destroy the regulator.
CAUTION
Never under any circumstance permit a ground to contact the field
circuit even for an instant while power is applied to the system.
g. The alternator should be in good condition and capable of producing full output, and the
alternator drive belt must be adjusted tight enough to prevent slippage.
h. The battery must be in good condition and should be fully charged.
i. The voltmeter and ammeter should be of the best quality and should be accurate.
j.
A carbon pile connected across the battery may be used to load the charging circuit while testing
the regulator.
Reissued: 10 / 11 /79
ELECTRICAL SYSTEM
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