Cen c720 alternator description and operation – C.E. Niehoff & Co. C720 Troubleshooting Guides User Manual
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Page 2
TG0036A
Section A: Wiring Diagrams
B– terminal
stud
W terminal
Figure 2 — C720 Alternator with A2-206 Regulator
Figure 1 — C720 Alternator Terminals
B+ terminal stud
T
T
T
T
T
T
T
T
T
T
T T T T T
DF (D+)
terminal
T T T T T
CEN C720 Alternator
Description and Operation
C720 28 V (300 A) alternator is self-rectifying.
All windings and current-transmitting components
are non-moving, so there are no brushes or slip rings
to wear out. The alternator has a DF (orD+) terminal
for a charge warning lamp, and a W terminal for a
tachometer or control circuit.
When controlled by the
A2-206 regulator, this alternator
becomes self-energizing through internal diode trios.
Residual magnetic field induces small voltage in stator
and energizes field coil. Field coil continues receiving
incremental voltage until full voltage is achieved. AC is
rectified into DC output through diodes. Regulator
controls voltage output.
Regulator has overvoltage cutout (OVCO). Regulators
with OVCO (overvoltage cutout) will trip at vehicle
electrical system voltages
above 33 volts that exist
longer than 3 seconds. OVCO feature detects high
voltage and reacts by signaling F+ alternator circuit
to open. This turns off alternator. Restarting engine
resets OVCO circuit. Regulator regains control of
alternator output voltage.